annual broadleaved weeds, including Consolida regalis Gray. During stem node stage treatment, a reduction in the efficacy of all herbicides and herbicide tank ...
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LATE USE OF HERBICIDES IN DURUM WHEAT CROP (TRITICUM DURUM DESF.) MONOGRAPH
Author: Assoc. Prof. Dr. Grozi Delchev, PhD
PREFACE
This Monograph includes studies on chemical control of weeds in durum wheat. In the investigations have been tested 21 antibroadleaved herbicides 5 antigraminaceous herbicides, 2 combined herbicides, 1 total herbicide and 4 herbicide tank mixtures. They are applied during tillering, stem elongation or maturing stages of durum wheat. All of experiments were carried out during 2004 – 2014 period. The experiments were carried out with 4 Bulgarian durum wheat cultivars (Triticum durum Desf.). It was investigated the influence of herbicides and herbicide tank mixtures on durum wheat grain yield, grain quality for processing and sowing characteristics of seeds. It was established technologically the most valuable variants from the viewpoint of technology for durum wheat growing.
1
ȱ. INTRODUCTION The late optimal sowing time of durum wheat greatly limited opportunities to fight against weeds in the autumn – during after sowing, before germination period (Delchev, 2003, 2003a, 2003b) and also makes this fight almost impossible during the 3-rd leaf stage of durum wheat. This stage usually begins late in the autumn or the beginning of winter and in most years is accompanied by low temperatures and high soil and atmospheric humidity. These specific characteristics of durum wheat required the fight against weeds is carried out mainly in spring during tillering stage of durum wheat. It was established many herbicides and herbicide combinations which can be used during tillering stage (van Himme and Bulcke, 1989; Glusaþ and Malašaviþ, 1994; Kozaczenko, 1995; Mueen-ud-Din and Ahmad, 2011; Sangi et al., 2012; Shehzad et al., 2012). Often under the influence of various factors - meteorological, organizational, financial et al. - the fight against weeds overdue and durum wheat is entering in stem elongation stage. The question of herbicides selectivity with regard to the plants during stem elongation stage of durum wheat still not well investigated. The spreading of perennial broadleaved weeds and increasing competition between them and durum wheat becomes these weeds in more technological problem during cultivation of this crop (Zinchenko and Tobolinoy, 1988). The studies of many authors indicate that in the fight against perennial broadleaved weeds the highest efficacy is the chemical method (Orth, 1965; O’Sullivan, 1980; Ahmed et al., 1993). Many herbicides are created that not only destroyed above ground mass of perennial weeds, but inhibit the formation of new shoots, both
2
during the wheat vegetation and also after its harvest in the stubble period. For achieving the high efficacy the surface parts of perennial weeds must be well developed in order to absorb the maximum amount of herbicide (Smajlagiü and Ĉikiü, 2011; Nakayama et al., 2010; Gupta et al. 2011). In some years under the influence of weather conditions, shoots of perennial weeds appear later in the spring and to the formation of their optimal size for herbicide action durum wheat is entering in stem elongation stage. This requires the fight against perennial weeds sometimes be done during the early periods of this stage. The creation high-producing crops of durum wheat and obtaining high-quality grain requires efficacy weed control (Kieloch et al. 2008; Stashinskis, 2008). In its evolutionary development weeds have gained mechanisms for adaptation to adverse conditions. This is why they are especially harmful in drought due to their great ecological plasticity and adaptability compared to the cultivated plants and that makes them more competitive (Heap, 1999). In creating environment of ever louder and more frequent drought are appear serious problems that must be solved (Labrada, 2000; Shehzad et al., 2012). One of them is for the efficacy and for the selectivity, i.e. about the behavior of foliar-applied and soil-applied herbicides under these conditions. We need to consider a number of factors that determine the effective application of these complex organic compounds. Pesticides will remain in the future agriculture an effective means of weed control as part of integrated control, which is why there is need for research for optimization of the their use (Kudsk and Streibig, 2003; Adamczewski and Paradowski, 2004; Khan et al., 2006). Increased application of herbicides in the agricultural practices raises many open questions about their effect on the quality of obtained products. 3
It has been carried out a number of attempts to establish the efficacy of different herbicides for weed control in durum wheat fields (Alegri, 1998; Montemurro; 1998; Holm et al., 2000). It is still insufficient studies on the reaction of different cultivars to some herbicides (Rapparini et al., 1998; Rola et al., 1999). At foliar application of herbicides weather conditions in the region are an important condition for the occurrence of the herbicidal effect and establish their influence on cultivated plants (Kucharski and Sadowski, 2004). Studies show that the quantity and quality of the grain are in direct dependence on weather conditions during the treatment with herbicides and during the period following the treatment (Citron et al., 1998; Stashinskis, 2001; Cacak-Pietrzak et al., 2008; Delchev, 2015). When using herbicides in the practice it is necessary to know not only the sensitivity of weeds about them but also their specific effect on the wheat plants (Orlando, 1994; Kudsk and Streibig, 2003; Hassan et al., 2008; Shehzad et al, 2012). Durum wheat compared to common wheat exhibits specific sensitivity to some herbicides (Rapparini et al., 2004; Campagna and Rueegg, 2006). There are data for the changes in the values of grain yield and grain quality (Baerg et al., 1996; Lobkov et al., 2012). The treatment of seed production crops of durum wheat with herbicides is an important moment of the technology of cultivation. We found from our previous studies that sowings seeds properties of different durum wheat cultivars are changed differently under influence of some herbicides applied during tillering stage (Delchev, 2015).The question of the influence of herbicides applied during stem elongation stage of durum wheat on sowing properties of durum wheat seeds is not fully explored (Borojevic et al., 1990; Yenish and Young, 2000; Belanovskaya et al., 2006). 4
The use of herbicides leads to large changes in the number and the species composition of weeds in wheat agrophytocenoses. Chemical weed control is associated with a significant improvement in plant health of wheat crops (Lizanko et al., 1988; Valenti and Wicks, 1992; Rapparini et al., 1994; Clay et al., 1995; Grundy et al., 1996; Markovic et al., 1998 and 2000; Kostrzewska, 2000; Michel, 2001; Jedruszczak et al., 2004; Zewdie and Rungsit, 2005; Buczek et al., 2007; Kieloch et al. 2008; Stashinskis, 2008; Nakayama et al ,. 2010; Gupta et al., 2011; Smajlagiü and Ĉikiü, 2011; Lobkov et al., 2012). Abtali et al. (1995) investigated the effectiveness of herbicides Topic (clodinafop-propargyl), Grasp (tralkoxydim), Scorpio Super (fenoxapropethyl) and Iloxan (diclofop-methyl), applied at the end of tillering of wheat and 4-6 leaf weeds. They provide 100 % control of Avena fatua L. and Avena ludoviciana Durien. Four antigramineous herbicides not cause phytotoxicity in wheat plants, even higher doses of the treatment. The yield of wheat is increased significantly when compared to all the herbicides weeded controls, but no difference between the individual herbicides. Herbicide Axial (pinoxaden) has high efficiency against graminaceous weeds and good selectivity for common wheat, durum wheat and barley (Campagna and Rueegg, 2006). Herbicide Derby Super (aminopyralid + florasulam) has an excellent efficacy against annual and perennial broadleaved weeds (Dalla Valle et al., 2006). Pasquini et al. (2006) reported about efficacy of Granstar (tribenuron-methyl) against these weeds.
Herbicides
imazamethabenz,
diclofop-methyl,
tralkoxydim,
fenoxaprop-P-ethyl and clodinafop-propargy are most efficacious against wild oat species (Tiebaset al., 1999). Imanat (2002) found that herbicides Topic and Logran are most efficient at higher soil and atmospheric humidity. 5
The high efficiency of the herbicide Hussar max (mesosulfuron + iodosulfuron) against gramineous and broadleaved weeds report Ceconi et al. (2000) and Cittar et al. (2002). According Montemurro et al. (2006) iodosulfuron + mesosulfuron (Atlantis) is more effective than metribuzin (Zenkor), 2.4-D + metosulam (Sound) metosulam (Eclipse) and herbicide mixture proporgil-clodinafop (Topic) + tribenuron-methyl (Granstar). Soroka et al. (1999) reported that the herbicide Zirol destroys all of broadleaf weeds which are resistant to hormone similar herbicides 2.4-D and 2M-4X. Weed control with herbicide Marathon in autumn is more effective than herbicides Cougar and Hussar Turbo (Tsyuganov and Potarenko, 2011). The results obtained from Bassi et al. (2002) showed supplement the spectrum of broadleaved weeds controlled by the tank herbicidal mixture carfentrazone-ethyl + tribenuron-methyl, and no antagonism in the control of graminaceous weeds by combining the new herbicide carfentrazone-ethyl with fenokiprop-ethyl and clodinafoppropargyl. Due to the poor efficacy of antigramineous herbicides to Bromus ssp., Hamal et al. (1996, 1996a and 1998) recommend chemical combat these weeds can be combined with soil cultivation. These results were confirmed by Kelley et al., (1998), according to which the fight against these dangerous weeds of wheat should focus the predecessors. The seriousness of the problem with Bromus ssp. is reported by Koscelny et al. (1996) and Koscelny and Peeper (1997). Tityanov et al. (2009) found higher efficacy of the herbicide Palace (piroxulam) against Avena fatua L., Alopecurus myosuroides L., Lolium multiflorum L. and Bromus arvensis L. Efficiency does not change with the introduction of the Palace as a tank mixture with Derby Super (florasulam + aminopyralid). It was reporting weak antagonism in the tank mixture Palace + Mustang (florasulam + 2.46
D ester) and strong antagonism in the tank mixture Palace + Herboxon (2.4-D amine salt). There are no symptoms of phytotoxicity at none of the variants. Herbicide Attribute than annual gramineous weeds Alopecurus myosuroides L., Apera spica-venti P.B. and Bromus arvensis L., due to systematic action also destroys roots of the perennial wheat weed Agropyrum repens L. (Ammon et al., 2000). Soukup et al. (2000) found that the herbicide mixtures of sulfonylurea herbicides with hormone-similar herbicides do not have a higher effect on Cirsium arvense Scop. and other perennial broadleaved weeds compared with separate application of these herbicides. Fenoxaprop-ethyl (Puma Super) tralkoxydim (Grasp) and diclofop-methyl (Iloxan) are highly effective against Avena ludoviciana Durien, but imzametabenz (Acer) is not effective against this annual gramineous weed (Montazeri, 1994). Adamczewski and Paradowski (2004) studies the biological efficacy of
herbicides
Attribute
(propoxycarbazone-sodium)
and
Apiros
(sulfosulfuron) found that the addition of adjuvants to both herbicides have a positive influence on herbicide effect and increase the yield of wheat grain. The lowest grain yield was obtained after the use of herbicides Attribute and Apiros without adjuvants. Adjuvants Adbios, Aero, Atpolan and Olbras increase most the efficacy of the tested herbicides. Ammonium nitrate used as adjuvant showed the weakest effect. Attribute herbicide is more efficient in the control of graminaceous weeds in comparison with Apiros. On the other hand, Apiros better control the broadleaved weeds. Both herbicides have a long persistence. After application Attribute (propoxycarbazone-sodium) must be grown winter oilseed canola, spring oilseed canola and sugar beet. After using Apiros (sulfosulfuron) should not be grown winter oilseed canola, however, can be grown spring oilseed canola and sugar beet. 7
Markovic (1990) investigated the influence of some herbicides: Glean, Racer, Banvel D, Monosan, Racer + Banvel D, Granstar, Granstar + Glean, Harmony, Chisel, Dicuran, Granstar + Banvel D, Buktril, Satis, Starane, Glean + Racer imported in period after sowing before emergence of wheat and in 3 - 4 leaf stage in autumn. Efficiency and selectivity of herbicides and their combinations depend on weather conditions, their period of application and the stage of development of culture. Similar results were reported by Ognjanovic and Lomovic (1994). Callens et al., (1996) reported about increase the efficacy of herbicides Puma Super and Topic upon the addition of adjuvants. The effect is the best of the addition of the adjuvant Atplus. The combination of antigramineous herbicides Puma Super and Topic with antibroadleaved herbicide Buktril increased grain yield by 58 % to 107 % depending on the level of weed density (Hassan et al., 2003 and 2008). The tank mixture of herbicides Puma Super + Secator also has high efficacy against gramineous and broadleaved weeds (Gorbacheva et al., 2011). In tank mixtures Puma Super and Topic with Arelon exists synergism with regard to gramineous weeds (Khan et al., 2002 and 2003). Ahmed et al. (1993), Khan and Noor-ul-Haq (1994 and 2002), Khan et al. (1999 and 1999a), Hashim et al. (2002), Cheema and Akhtar (2005) and Sangi et al., (2012) report about high herbicidal efficacy of herbicides Arelon, Graminon, Tribunil, Buktril, Dicuran, Tolcan and Dozanex. The increase in grain yield is due to the increase of the productive tillering, the grains number per spike and the 1000 grains weight. The efficacy of the mixtures of these herbicides with hormone-similar herbicides is commented by Marwat et al. (2002 and 2005) and Mueen-ud-Din and Ahmad (2011). The combination of the herbicides Arelon and Zencor
8
affords higher grain yields compared to their separate application (Khan et al., 2006). Bartolini et al. (2002) and Bucchi et al. (2006) investigated the phytotoxicity in some common wheat cultivars by the influence of herbicides and herbicide tank mixtures iodosulfuron + fenoxaprop-ethyl, tralkoxydim, clodinafop-proporgil, fenoxaprop-ethyl, fenoxaprop-ethyl + diclofop-methyl, fluroxypyr + clopyralid + MCPA and tribenuron methyl + fluroxypyr. The results show that all the investigated variants have good tolerance to investigated common wheat cultivars. Some mixtures have weak phytotoxicity, but it does not lead to a reduction in grain yield. These variants have good tolerance and a large number of durum wheat cultivars (Rapparini et al., 1998, 2000 and 2002; Geminiani et al., 2006). Antigramineous herbicides Iloxan, Grasp, Topic and Puma Super, which are completely selective to common wheat showed a higher phytotoxicity to durum wheat (Bell 1999). Camele and Rana (1995) also reported that the durum wheat is characterized by higher sensitivity to some herbicides compared to the common wheat. Amidosulfuron, carfentriazon-ethyl, fluroxypyr, florasulam and ciklosulfuron have high efficacy against Galium aparine L. Metosulam, metsulfuron-methyl, tribenuron-methyl and rikolinofen show less effect against this weed (Covarelli, 1998; Covarelli and Stagnari, 2002). Chlorotoluron, chlorbromuron, dicamba and bentazone exhibit high selectivity for the most common wheat cultivars (Dadari et al., 1990). Korres et al. (1999) have reported that isoproturon and chlorotoluron in different wheat cultivars cause damage to varying degrees. Damage from these two herbicides decreased with increasing plant density of 1 m2. Isoproturon reduces grain yield in the susceptible cultivars due to the lower grades of 1 m2. Tralkoxydim decreases less yield because less impact on 9
the yield components (Kumar et al., 1997). According Kulshresta et al. (1999) in resistant wheat biotypes the isoproturon is degraded completely to 8 days after treatment. In sensitive biotypes it degrades for more than 18 days. Dastgheib et al. (1994) found that 48 hours after treatment resistant to chlorsulfuron cultivars degrade more than 90 % of herbicide and the sensitive - about 40 %. Hormone-similar herbicides Lontrel 418 C (MCPP + 2.4-D), Morogal (MCPP + MCPA) and Monosan C (2.4-D + MCPA), introduced in stem elongation stage of the wheat lead to a reduction in grain yield, spike length, numbers of spikelets and grains per spike and plant height. When introduced in tillering stage, such a reduction is not found (Bozinovic, 1996). Glusac and Malasavic (1994) and Marinkovic et al. (1997) also reported the decrease in the yield by treatment during of stem elongation stage. Herbicides Puma Super in treatment in the stem elongation stage not reduce grain yield, but herbicide Asert reduces grain yield (Holm et al., 2000). Puma Super causes phytotoxicity in some wheat cultivars. Combination Puma Super + Asert reduces phytotoxicity as compared with their separate treatments (Liu et al., 1994). Rola et al. (1999) found that many wheat cultivars are sensitive to herbicides Glean and Stomp which treated after sowing - before germination; to herbicide Dicuran which treated in autumn in third leaf stage and to herbicide Arelon which treated in spring in tillering stage. Most of the investigated cultivars by these authors, however, are tolerant to these herbicides. Wheat and maize resistance to the herbicide chlorsulfuron is determined by the dominant condition of a particular gene and sensitivity - of recessive condition of this gene (Yang and Wu, 1994). Baerg et al. (1996) reported about antagonism between diclofopmethyl (Iloxan) and tribenuron-methyl (Granstar). Tribenuron difficult 10
diclofop translocation in wild oat‘s meristem tissues. Brzozowska end Brzozowski (2002) found that leaf treatment with the combination of herbicide Granstar (tribenuron-methyl) and urea increased the amount of grain yield, but reduces the protein content of the grain of the common wheat. Combined treatment of herbicides Arelon (isoproturon), Partner (isoproturon + diflufenican), Dublet (isoproturon + bromoxynil + MCPA) and Agmol Kombi (cypermethrin + MCPA) with urea, however increases the yield and quality of the wheat grain (Tanveer al., 1999). Combined use of dicamba and metsulfuron with urea ammonium nitrate (UAN) also increases the yield and grain quality (Wicks et al., 1995). Efficacy and selectivity as one of the most important parameter for assessment the effect of chemical treatment against weeds has been investigated for a large number of herbicides and herbicide combinations by many authors (Wybieralski and Wybieralska, 1984; Salarzai et al., 1999; Rapparini et al., 1997, 1998, 2000, 2004, 2004a; Lukyanyuk and Gaytyukevich, 2007; Chernuha and Dolzhenko 2009; Shehzad et al., 2012). In investigation of herbicides Puma Universal, Secator and Hvastox Extra, Cacak-Pietrzak et al. (2008) found that a higher dose of Secator reduce grain yield and gluten quality in the two cultivars of common wheat. Stashinskis (2001, 2001a) reported higher increase of quality indicators at spring wheat cultivars in compared weeded control than at winter wheat cultivars in the use of herbicides Lintur, Secator, Ariana and Duplozan Super. The reasons for this are the different stages of development of the plants of both species wheat and most natural competitiveness of winter wheat, as a result of which it is easier to deal with weeds. Kostowska et al. (1994) found residues of the herbicide chlorotoluron and isoproturon in three cultivars of common wheat. In other cultivars of research a wide range, such is not found. Residues of 11
investigated herbicides in grain have always been lower than the limit. There are no residues in the grain of the herbicides 2.4-D, MCPA, dicamba (Kucharski and Sadowski, 2004). Belanovskaya et al. (2006) found that treatment of wheat, barley, rye and triticale with herbicide glyphosate 10-12 days before harvesting, decreases the protein content of rye grain and triticale grain respectively by 0.29 % and 0.12 %, and increases the protein content of the wheat grain and barley grain by 0.47 % and 0.54 %. Yenish and Young (2000) investigated the influence of preharvest treatment with glyphosate at 2 wheat cultivars. Glyphosate was applied at different doses in stages milk ripeness (Zadoks' scale 79), wax ripeness (Zadoks' scale 85) and full ripeness (Zadoks' scale 87). The grain yield decreased only when treatment is done in milk ripeness from 20 to 77 % depending by the year, by the cultivar and by the dose of glyphosate. The 1000 grains weigh decreases from 19 to 73 %, while the germination decreases from 2 to 46 %. The following year, by the use of these seeds decreased: crop density - from 28 to 99 %, plant height - from 19 to 39 %, and the grain yield - from 12 to 97 %. The decrease depends strongly by the stage of ripeness of the wheat during treatment and less by cultivar and by the dose of the herbicide. Treatment of common wheat with the herbicide 2.4-D, MCPP and MCPA in wheat growing season, leads to decrease in length of the primary root and coleoptile upon seed germination (Borojevic et al., 1990). Literature review demonstrates the views of cited authors formulated a series of laws. Chemical control has emerged as the most efficient method of weed control. Herbicides combinations and tank mixtures of herbicides with adjuvants, fertilizers, growth regulators, fungicides, insecticides, are more effective than when they are applied alone in wheat 12
crops. Their combined use often leads to high synergistic effect on yield. Many authors present data from which it is clear that durum wheat differs from common wheat in their reaction to some herbicides, herbicide combinations and herbicide tank mixtures. Although without claim to be exhaustive literature review should be noted, that a serious problem in wheat is Bromus arvensis L. due to their resistance to most antigramineous herbicides. In recent years entering effective herbicides to fight against them, but their number is still too limited. Problem is the persistence of some herbicides used in the predecessors on succeeding crops, which is directly related to the weather conditions during their degradation. On some problems are published contrary opinions, due primarily to the different conditions under which the experiments were conducted and the biological characteristics of the tested cultivars. Most of the information on these subjects mainly refers to common wheat and only a limited number of it is for durum wheat. A serious problem is also the self-sown plants of Clearfield canola (Brassica napus L.), Clearfield and Express sun sunflower (Helianthus annuus L.). They have resistance to herbicides different from that one of conventional canola and sunflower hybrids. A problem is also self-sown plants of coriander (Coriandrum sativum L.) and milk thistle (Silybum marianum Gaertn.). There is no information still in the scientific literature to control of these self-sown plants.
13
ȱȱ. PURPOSE AND TASKS OF INVESTIGATION The biology of durum wheat, as well as the need to increase crop yields and quality, requires the application of optimal agro-technology consistent with the area and the field specificity. In recent years, as a result of constantly rising global fuel prices, farmers have reduced part of their soil tilths due to the fact that they are the most energy-intensive part of the growing technology of each crop. As a result, the main burden of weed control is transferred to herbicides. The ban on burning stubble in Bulgaria has further increased the importance of chemical weed control. In addition, the issue of the impact of herbicides on the environment is also particularly acute. Without claiming to be exhaustive, it should be pointed out that most of the studies on chemical weed control are related to the efficacy and selectivity of herbicides. Less attention is paid to questions related to differences in their efficacy under the influence of weather conditions. The formation of highly effective crops of durum wheat by adapting their cultivation technology to the specific soil and climatic conditions of the area, including highly effective weed control, is one of the main roads for obtaining stable yields of high-quality grain. Expanding and deepening research on both the factors on which the quantity depends, as well as on the quality of the produce and the seed material are timely and useful for theory and practice. Chemical weed control is highly effective but relatively costly and with significant effects on the environment. Enhancing the food and environmental crisis and the problems of ownership, hiring and land tilth at this stage raises the actuality of the problem.
14
Based on the literature review and the needs of the practice, the present study PURPOSES to establish the influence of some herbicides and herbicide tank mixtures on durum wheat (Triticum durum Desf.) grain yield, grain quality for processing and sowing characteristics of seeds as well as technologically the most valuable variants from the viewpoint of technology for durum wheat growing. To achieve the stated purpose, attention was directed to the following TASKS: 1. To establish of the productivity and selectivity of grain yield by influence of some antibroadleaved and antigraminaceous herbicides, applied during 1-st, 2-nd and 3-rd stem node stages of durum wheat. 2. To establish of the changes on structural elements and grain quality by the influence of some antibroadleaved and antigraminaceous herbicides, applied during 1-st, 2-nd and 3-rd stem node stages of durum wheat. 3. To establish of the changes in sowing properties of seeds and in the quantity of waste grain by the influence of some antibroadleaved and antigraminaceous herbicides, applied during 1-st, 2-nd and 3-rd stem node stages of durum wheat. 4. To test of combined herbicides and herbicide tank mixtures against economically important weeds, applied during tillering and stem elongation stages of durum wheat. 5. To investigate their effect on the structural elements of the yield, the grain quality and the sowing properties of the seeds. 6. To test of the efficacy and selectivity of foliar systemic nonselective herbicide Glyphosan, applied during milk development, dough development and ripening stages of durum wheat.
15
7. To investigate the effect of this herbicide on the structural elements of the yield, the grain quality and the sowing properties of the seeds.
16
ȱȱȱ. MATERIALS AND METHODS 1. IVESTIGATED VARIANTS The investigations were conducted during the period 2004 - 2014. They were carried out 4 field experiments with durum wheat (Triticum durum Desf.). All experiments were carried out as a block method in 4 repetitions, on a 20 m2 harvesting area, on pellic vertisol soil type, after sunflower predecessor. First experient was conducted during 2012 - 2014 with Bulgarian durum wheat cultivar Victoria (Triticum durum Desf. var. valenciae). For exploration the possibilities to fight with secondary weed infestation with broadleaved weeds in durum wheat crop for processing 20 antibroadleaved herbicides were investigated. The active substances and doses of the investigated herbicides are given in Table 1. The weak adhesion of herbicides Granstar, Granstar super and Ally max required their application with adjuvant Trend 90 - 0.1%. The weak adhesion of herbicides Arat and Biathlon required their application with adjuvant Dash HC - 500 ml/ha. All herbicides were treated during 1-st, 2-nd and 3-rd stem node stages of durum wheat. All variants are applied with working solution consumption 200 l/ha. To examine only the influence of herbicides and eliminate the negative influence of weeds they are removed by hand weeding during the growing period. Second experient was conducted during 2004 - 2006 for exploration the possibilities to fight with secondary weed infestation with graminaceous weeds in durum wheat crop. Factor A included 2 Bulgarian durum wheat cultivars - Progress, which belongs to var. leucurum and
17
Table 1 Investigated antibroadleaved herbicides ʋ
Herbicide
1
Check
2
Granstar 75 DF
3
Granstar super 50 SG
4
Ally max SG
5
Arat
6
Active substance
Doses
-
-
tribenuron-methyl tribenuron-methyl + tifensulfuronmethyl
25 g/ha 40 g/ha
metsulfuron-methyl + tribenuron-methyl
35 g/ha
tritosulfuron + dicamba
200 g/ha
Biathlon 4 D
tritosulfuron + florasulam
55 g/ha
7
Derby super WG
florasulam + aminopyralid
33 g/da
8
Mustang 306.25 SC
florasulam + 2.4-D
800 ml/ha
9
Weedmaster 646 CL
2.4-D + dicamba
1 l/ha
10
Sunsac
metosulam + 2.4-D
1 l/ha
11
Secator OD
iodosulfuron + amydosulfuron
100 ml/ha
12
Logran 60 WG
triasulfuron
37.5 g/ha
13
Lintur 70 WG
triasulfuron + dicamba
150 g/ha
14
Akurat 60 WG
10 g/ha
15
Akurat extra WG
50 g/ha
16
Eagle 75 DF
metsulfuron-methyl metsulfuron-methyl + tifensulfuronmethyl chlorsulfuron
17
Herbaflex
beflubutamid + isoproturon
2 l/ha
fluroxypyr
1 l/ha
2.4-D
2 l/ha
2M-4X
4 l/ha
2.4-D + 2M-4X
1.4 l/ha
18
Starane 250 EK
19
Sanafen
20
Dicotex 400
21
Herby 675
15 g/ha
Vuzhod, which belongs to var. valenciae. Factor B included no treated control and 4 herbicides: Puma super, Grasp, Topik, Hussar max. The active substances and doses of the investigated herbicides are given in Table 2. The weak adhesion of Grasp and Hussar max required their application with adjuvant - accordingly Atplus and Genapol.
18
Table 2 Investigated antigraminaceous herbicides ʋ
Variants
Active substance
Doses
1
Control – no treated
-
-
2
Puma super EB 7.5
phenoxyprop-ethyl
1 l/ha
3
Grasp 25 EC
tralkoxydim
1.2 l/ha
4
Topic 080 EC
clodinafop
450 ml/ha
5
Hussar max WG
mesosulfuron + iodosulfuron
250 g/ha
Herbicides Grasp and Hussar max are used with adjuvant respectively Atplus – 1.2 l/ha and Biopower – 250 ml/ha.
All herbicides were treated during 1-st, 2-nd and 3-rd stem node stages of durum wheat. All variants are applied with working solution consumption 200 l/ha. To examine only the influence of herbicides and eliminate the negative influence of weeds they are removed by hand weeding during the growing period. Third experiment was conducted during 2009 - 2011 with Bulgarian durum wheat cultivar Zvezditsa. It was investigated the efficiency and selectivity on the durum wheat of 6 new products: 1 combined herbicide Axial one; 2 antigrass herbicides - Axial 050 EC and Traxos 050 EC a; 3 antibroadleaved herbicides - Lintur 70 WG, Logran 20 WG and Bromotril 24 EC. It was investigated 4 tank mixtures between antigrass and antibroadleaved herbicides: Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur. The active substances and doses of the investigated herbicides and tank mixtures are given in Table 3. All of herbicides and herbicide tank mixtures were treated in tillering and stem elongation stages of the durum wheat, with working solution 200 l/ha. Mixing was done in the tank on the sprayer. Fourth experiment was conducted during 2008 - 2010. Factor A included 2 Bulgarian durum wheat cultivars - Victoria and Predel, which
19
Table 3 Investigated herbicide combinations ʋ
Variants
Active substance
Doses
-
-
1
Control – no treated
2
Axial one
pinoxaden + florasulam
1 l/ha
Axial 050 ȿɄ + Lintur 70 WG Axial 050 ȿɄ + Logran 20 WG Axial 050 ȿɄ + Bromotril 24 EC Traxos 045 ȿɄ + Lintur 70 WG
pinoxaden triasulfuron + dicamba pinoxaden + clodinafop triasulfuron pinoxaden bromoxynil-octanoate pinoxaden + clodinafop triasulfuron + dicamba
900 ml/ha 150 g/ha 1.3 l/ha 37.5 g/ha 800 ml/ha 200 ml/ha 1.3 l/ha 150 g/ha
3 4 5 6
belongs to Triticum durum var. valenciae. Factor B included 4 rates - no treated check and 3 durum wheat stages for treatment with herbicide Glyphosan: milk development (Zadoks’ scale 77), dough development (Zadoks’ scale 85) and ripening (Zadoks’ scale 92) of the durum wheat. Foliar systemic non-selective herbicide herbicide Glyphosan 36 SL (360 g/l glyphosate) was treated in dose 12 l/ha, with working solution 300 l/ha. All other agronomic practices were carried out according to technology for growing of durum wheat.
20
2. RESEARCHED INDICATORS Phenological observations, biometric measurements and chemical analyzes were conducted during the experimental work. It was investigated efficacy and selectivity of herbicides and their tank mixtures. Efficacy of herbicides against weeds was appointed according to 100 % scale of EWRS (European Weed Research Society). The number and species composition of weeds and self-sown plants were determined prior to treatment and 7, 14 and 21 days after treatment. Percentages of efficacy were determined according to the EWRS methodology. Some of the weeds that were missing or found in single specimens were sown manually during sowing of the crop. Their seeds are collected from other areas in the Chirpan region and the surrounding villages where these weeds meet in greater density. Selectivity of herbicides to durum wheat plants was followed according to the 9-rate scale of EWRS (rating 1 - without damages, rating 9 - crop is completely destroyed). For foliar applied herbicides, it is reported up to 21 days after treatment and for soil-applied herbicides after the crop. Grain yields of wheat are determined in all variants - in kg/ha and in %. They are assimilated to 12 % grain moisture (standard humidity). To better explain the effect of herbicides on grain yields of durum wheat, their structural elements that determine the yield are determined. Durum wheat is a "crop of quality". It is used exclusively for human food. In order to better explain the corresponding reactions and manifestations of the various herbicides and herbicide mixtures on the durum wheat grain, samples were taken from all variants and the physical
21
and biochemical properties that most influence the quality of the grain were determined. To investigate the effect of herbicides and herbicide tank mixtures on sowing-seeds, the indicators have a direct impact on the seed characteristics of durum wheat seeds are detected. Definitely is also a quantity of waste grain (siftings) in the preparation of these seeds.
22
3. MATHEMATICAL PROCESSING OF THE OBTAINED RESULTS Statistical evaluation to rate the representativeness and reliable effect of the studied parameters has been applied through dispersion analysis and Fischer’s parametric criterion F (Shanin, 1977; Barov, 1982). In the variance analysis the ANOVA123 software is used for calculation (Lidanski, 1988). Such analysis is done for: - the grain and seed yields; - the structural elements of the yields; - the physical and biochemical properties of the grains; - the sowing characteristics of the seeds. The selectivity of herbicides was established through their effect on grain or seed yields and the following variances have been calculated: Shukla, (1972) stability variance (ıi2) ݄ܵ െ ߪଶ ൌ ሾͳΤሺ݁ െ ͳሻ ሺ ݐെ ͳሻሺ ݐെ ʹሻሿ ௦
ଶ
௧
௦
ଶ
ൈ ݐሺ ݐെ ͳሻ ൫ݑ െ ݑത ൯ െ ൫ݑ െ ݑത ൯ ୀଵ
ୀଵ ୀଵ
where: ݑ ൌ ܺ െ ܺതǤ ܺ ൌ observed trait value of ith cultivar in jth environment, ܺതǤ ൌ mean of all cultivars in jth environment,
ݑതǤ ൌ ݑ Τ݁ ୀଵ
݁ ൌ number of environments, ݐൌ number of cultivars.
23
In this study, calculation of adjusted stability variance (Sh – Si2) was necessary, because the heterogeneity term was significant (ܲ ൏ ͲǤͲͳ). The stability statistic Sh-Si2 calculated following removal of heterogeneity due to environmental index (ܼ ൌ ܺതǤ െ ܺതǤǤ ) as a covariate from GE interaction variance, where ܺതǤ ൌ mean of all cultivars in jth environment and ܺതǤǤ ൌ mean of all cultivars across all environments, using the following equation (Shukla 1972): ௧
݄ܵ െ
ܵଶ
ൌ ሾݐΤሺ ݐെ ʹሻሺ݁ െ ʹሻሿ ൈ ݏ െ ݏ Τݐሺ ݐെ ͳሻ൩ ୀଵ
where: ௦
ݏ ൌ ൫ݑ െ ݑതǤ െ ܾ ܼ ൯
ଶ
ୀଵ ௦
ܾ ൌ
௦
ൣ൫ݑ െ ݑǤ ൯ܼ ൧൘ ܼଶ
ୀଵ
ୀଵ
Cultivar stability across multiple years and locations also was evaluated using the ecovalence (Wi) (Wricke 1962): ௧
ܹଶ
ଶ ൌ ൫ܺ െ ܺതǤ െ ܺതǤ ܺതǤǤ ൯ ୀଵ
Greatest stability is when ܹ ൌ ܹଶ ൌ Ͳ. For grain yields stability parameters have been calculated. Stability variances (ıi2 and Si2) by Shukla (1972) and ecovalence Wi by Wricke (1962) show what portion of variation related to interaction of the preparations and years are accounted by the specific variant. Through the stability criterion (YSi) of Kang (1993) the value of each variant has been shown by simultaneous taking into account the parameter value and the stability of the variant. The value of that criterion is that by
24
using non-parametric methods and statistical reliability of differences we obtain a combined valuation ranking variants in a descending order according to their economic value. To calculate these parameters, the STABLE software of Louisiana State University Agricultural Center, Baton Rouge, USA (1993) was used. The following model was applied to assess the stability of various variants in their interaction with years: Xij = m + Ni + Yj + NYij +Lij where: Xij – grain parameter (yield, mass) of the i-th variant with j-th environment (year), m – general mean, Ni – effect of the ith variant, Yj – effect of the jth environment (year), NYij – effect of interaction of the ith variant with the jth environment (year), Lij – error relating to the ith variant in the jth environment (year).
25
ȱV. RESULTS AND DISCUSSION 1. CHANGES IN PRODUCTIVITY OF DURUM WHEAT BY LATE TREATMENT WITH ANTIBROADLEAVED HERBICIDES 1.1. Grain yields. Stability and technological value of yields during 1-st stem node stage For exploration the possibilities to fight with secondary weed infestation with broadleaved weeds in durum wheat fields for processing and for seed production 20 antibroadleaved herbicides were investigated: Granstar 75 DF, Granstar super 50 SG, Ally max SG, Arat, Biathlon 4 D, Derby super WG, Mustang 306.25 SC, Weedmaster 646 CL, Sunsac, Secator OD, Logran 60 WG, Lintur 70 WG, Akurat 60 WG, Akurat extra WG, Eagle 75 DF, Herbaflex, Starane 250 EK, Sanafen, Dicotex 400 and Herby 675. The active substances and doses of the investigated herbicides are described in detail in Table 1 of the Material and Methods section. The weak adhesion of herbicides Granstar, Granstar super and Ally max required their application with adjuvant Trend 90 - 0.1%. The weak adhesion of herbicides Arat and Biathlon required their application with adjuvant Dash HC - 500 ml/ha. All herbicides were treated during 1-st, 2-nd and 3-rd stem node stages of durum wheat. To examine only the influence of herbicides and eliminate the negative influence of weeds they are removed by hand weeding during the growing period.
26
Data about the influence of investigated antibroadleaved herbicides on grain yield are showed that herbicides Arat, Biathlon, Derby super, Mustang, Weedmaster, Sunsac, Secator, Lintur, Akurat, Akurat extra, Eagle, Starane, Dicotex and Herby, applied during 1-st stem node stage of durum wheat have not proved decrease on grain yield (Table 4). Special interest here causes herbicide Weedmaster with active substance dicamba. Durum wheat (Triticum durum Desf.) appears to have significantly higher resistance to this herbicide than common wheat (Triticum aestivum L.). Herbicides based on dicamba can be used not only during the tillering stage of durum wheat (Delchev, 2003, 2003a,2003b), but also during early stem elongation stage. At the same time, at common wheat these herbicides have significant phytotoxicity even during the tillering stage, especially in some cultivars (Orth, 1965, Ahmed et al., 1993). Herbicides Granstar, Granstar super, Ally max and Weedmaster cannot be used during stem elongation stage of durum wheat. When comparison of the data by years can be seen that yields in the particular years is different. During 2013 herbicides Granstar, Granstar super and Ally max has not proved decrease of grain yield. During 2013 herbicide Weedmaster leads to grain yield equal to this one from untreated check. This is due to different weather conditions in the particular years. Herbicides Logran, Herbaflex and Sanafen also cannot to be used during 1-st stem node stage, because they have high phytotoxicity to durum wheat. Bearing in mind the active substance of the three hormone-similar herbicides (Sanafen, Dicitex and Herby), was found that the herbicide of the base 2M-4X (Dicotex) has better expressed selective action on durum wheat in comparison with that of the base 2.4-D (Sanafen). Herbicide 27
Table 4 Grain yield of durum wheat at treatment during 1-st stem node stage (2012 2014) 2012 kg/ha %
2013 kg/ha %
2014 kg/ha %
Mean kg/ha %
Check
5184
100
5199
100
5299
100
5227
100
Granstar
4818
93.0
5233
100.6
4667
88.0
4906
93.8
Granstar super
4818
93.0
5251
101.0
4674
88.8
4929
94.3
Ally max
4818
93.0
5233
100.6
4728
89.2
4929
94.3
Arat
4930
95.1
5200
100.0
5079
95.8
5070
97.0
Biathlon
4928
95.0
5147
99.0
5034
95.0
5034
96.3
Derby super
5121
98.8
5133
98.7
5300
100.0
5188
99.2
Mustang
5028
97.0
4989
96.0
5167
97.5
5060
96.8
Herbicides
Weedmaster
4939
95.3
5200
100.0
5167
97.5
5102
97.6
Sunsac
5121
98.8
4883
93.9
4933
93.1
4979
95.3
Secator
5073
97.9
5250
101.0
5300
100.0
5207
99.6
Logran
4515
87.1
5033
96.8
4267
80.5
4605
88.1
Lintur
4818
93.0
4967
95.5
5033
95.2
9678
94.6
Akurat
4909
94.7
4939
95.0
5087
96.0
4976
95.2
Akurat extra
4925
95.0
4918
94.6
5087
96.0
4976
95.2
Eagle
4818
93.0
5100
98.1
5033
95.0
4984
95.3
Herbaflex
4864
93.8
4900
94.2
4733
89.3
4832
92.4
Starane
4909
94.7
5233
100.6
5233
98.7
5125
98.0
Sanafen
5122
98.8
4733
91.0
4940
93.2
4932
94.4
Dicotex
4909
94.7
5233
100.6
5033
95.2
5058
96.8
Herby
4939 351 465 604
95.3 6.8 9.0 11.7
4967 338 433 566
95.5 6.5 8.3 10.9
5467 376 488 600
103.1 7.1 9.2 11.3
5125
98.0
LSD 5% LSD 1 % LSD 0.1%
Herby due to its lower content of 2.4-D and lower dose per hectare also has better selectivity to durum wheat.
28
Weather conditions during the three years included in the investigation, were significantly different between them. Significant differences between years were very favorable for evaluation of investigated antibroadleaved herbicides.
Table 5 Analysis of variance for grain yield Source of variation
Degrees of freedom
Sum of squares
Influence of factor, %
Mean squares
Total
188
138094
100
-
Tract of land
2
40992
1.5
13961.0***
Variants
62
398966
96.5
31572.6***
2
198198
37.1
29363.4***
20
176855
34.9
31320.0***
40
163288
24.5
27754.7**
124
51606
2.0
303.8
Factor A – Years Factor B – Herbicides AxB Pooled error *p5%
**p1%
***p0.1%
Analysis of variance for grain yield (Table 5) shows that investigated variants have proven influence on grain yield – 96.5 %. The years have the highest influence on grain yield – 37.1 % on the variants. It is determined by unequal response of variants to changes in environmental conditions. The reason is the large differences in the meteorological conditions during the three years of investigation. The strength of influence of investigated herbicides is 34.9 %. The influence of years and preparations is well proven at p 0.1. There is an interaction between herbicides and meteorological conditions of years (AxB) – 24.5 %. It is well proven at p 0.1. That means that some of herbicides Granstar, Granstar super, Ally max, Arat, Biathlon, Derby super, Mustang, Weedmaster, Sunsac, Secator,
29
Logran, Lintur, Akurat, Akurat extra, Eagle, Herbaflex, Starane, Sanafen, Dicotex and Herby, applied during the 1-st stem node stage of durum wheat, have negative influence on grain yield which depends on different weather conditions in the particular years. Based on proven preparation x year interaction, it was evaluated stability parameters for each variant for grain yield of durum wheat with relation to years (Table 6). It was calculated the stability variances ıi2 and Si2 of Shukla, the ecovalence Wi of Wricke and the stability criterion YSi of Kang. Stability variances (ıi2 ɢ Si2) of Shukla, which recorded respectively linear and nonlinear interactions, unidirectional evaluate the stability of the variants. These variants which showed lower values are considered to be more stable because they interact less with the environmental conditions. Negative values of the indicators ıi2 and Si2 are considered 0. At high values of either of the two parameters - ıi2 and Si2, the variant are regarded as unstable. At the ecovalence Wi of Wricke, the higher are the values of the index, the more unstable is the variant. On this basis, using the first three parameters of stability, it is found that during 1-st stem node stage of durum wheat the most unstable are herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Herbaflex and Herby, followed by Mustang, Eagle, Sanafen and Dicotex. At herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Herbaflex and Herby values of stability variance ıi2 and Si2 of Shukla and ecovalence Wi of Wricke are the highest and mathematically proven. Instability is a linear type and a nonlinear type - proven values of ıi2 and Si2. At herbicides Mustang, Eagle, Sanafen and Dicotex instability is a linear type - proven values of ıi2, the values of Si2 are not proven. The reason for this high instability is greater variation in grain yields during years of experience as 30
Table 6 Stability parameters of herbicides for grain yield with relation to years at treatment during 1-st stem node stage ത
ıi2
Si2
Wi
YSi
Check
5227
203.7
5.8
402.6
22+
Granstar
4635
403.7**
250.5**
996.5
-8
Granstar super
4647
405.6***
339.3***
988.8
-4
Ally max
4642
485.6***
406***
913.4
-5
Arat
4987
297.9
108.8
562.3
19+
Biathlon
4945
328.2
65.3
633.2
18+
Derby super
5003
246.3
24.5
481.5
21+
Mustang
4913
188.8*
400.0
420.8
7
Weedmaster
5102
518.0
1.1
339.7
5
Sunsac
4630
121.9**
200.2**
200.8
-7
Secator
4982
32.0
62.1
84.7
17+
Logran
4605
408.3***
833.6***
781.5
-7
Lintur
4929
91.9
36.6
195.7
15+
Akurat
4913
99.5
47.6
209.7
17+
Akurat extra
4903
99.0
50.8
200.5
16+
Eagle
4984
307.8*
63.5
595.5
3
Herbaflex
4832
560.7***
126.0***
1063.8
-6
Starane
5125
95.9
51.6
185.7
7
Sanafen
4932
218.4*
2.8
200.6
3
Dicotex
5058
289.2*
52.1
532.2
4
Herby
5125
246.4*
60.3*
248.0
2
Herbicides
weather conditions affect those most. Other ninth herbicides Arat, Biathlon, Derby super, Weedmaster, Secator, Lintur, Akurat, Akurat extra and
31
Starane exhibit high stability because they interact poorly with the conditions of years. To evaluate the complete efficacy of each herbicide should be considered as its effect on grain yield of durum wheat and its stability - the reaction of wheat to this variant during the years. Valuable information about the value of technologic value of the variant give the stability criterion YSi of Kang for simultaneous assessment of yield and stability, based on the reliability of the differences in yield and variance of interaction with the environment. The value of this criterion is experienced that using nonparametric methods and warranted statistical differences we get a summary assessment aligning variants in descending order according to their economic value. Generalized stability criterion YSi of Kang, taking into accounts both the stability and value of yields gives a negative assessment of herbicides Granstar, Granstar super, Ally max, Sunsac, Logran and Herbaflex, characterizing them as the most unstable and low yields. These four herbicides receive low estimates due to their high phytotoxicity to durum wheat during applying in 1-st stem node stage of durum wheat. According to this criterion, during treatment in 1-st stem node stage of durum wheat, technologically the most valuable appears herbicides Derby super, Arat, Biathlon, Secator, Akurat, Akurat extra and Lintur. These herbicides combine high levels of grain yield and high stability of this index during the years. From the viewpoint of technology for durum wheat growing, during 1-st stem node stage good estimates have also herbicides Mustang, Weedmaster, Starane, Herby, Dicotex, Sanafen and Eagle. These herbicides combine good levels of grain yield and good stability of this index during the years.
32
1.2. Grain yields. Stability and technological value of yields during 2-nd stem node stage Data about the influence of investigated antibroadleaved herbicides on grain yield are showed that herbicides Arat, Biathlon, Derby super, Mustang, Sunsac, Secator, Lintur, Akurat, Akurat extra, Starane, Dicotex and Herby, applied during 2-nd stem node stage of durum wheat have not proved decrease on grain yield (Table 7). With the advancement of stem elongation stage (from 1-st to 2-nd stem node stage), herbicides Granstar, Granstar super, Ally max and Weedmaster have enhanced their phytotoxicity with regard to the durum wheat, which is especially strongly expressed at Weedmaster. When are compared the active substances of the three hormonesimilar herbicides (Sanafen, Dicotex and Herby) it is establishes that the herbicide of base 2M-4X (Dicotex) has better expressed selective action on durum wheat in comparison with that one of base 2.4-D (Sanafen). Herbicide Herby due to its lower content of 2.4-D and lower dose per hectare also has better selectivity to durum wheat. These differences between hormone-similar herbicides also continued during 2-nd stem node stage. Sanafen increase its phytotoxicity and Dicotex and Herby have good selectivity. During 2-nd stem node stage is occurred turning point with regard to reaction of durum wheat to herbicides based on chlorsulfuron (Eagle). Up to this point durum wheat shows no sensitivity to Eagle, regardless of cultivars, doses, weather conditions or period of applying: during after sowing - before emergence or during tillering stage (Delchev, 2003) or
33
during early stem elongation stage. From 2-nd stem node stage herbicide Eagle has high phytotoxicity during each year of investigation.
Table 7 Grain yield of durum wheat at treatment during 2-nd stem node stage (2012 - 2014)
Check
2012 kg/ha % 5184 100
2013 kg/ha % 5199 100
2014 kg/ha % 5299 100
Mean kg/ha % 5227 100
Granstar
4818
93.0
4933
94.9
4667
88.0
4806
91.9
Granstar super
4847
93.5
4939
95.0
4716
89.0
4835
92.5
Ally max
4818
93.0
4949
95.2
4716
89.0
4830
92.4
Arat
4900
94.7
5131
98.7
5087
96.0
5044
96.5
Biathlon
4873
94.0
5087
97.8
5034
95.0
4997
95.6
Derby super
4939
95.3
5000
96.1
5267
99.4
5069
97.0
Mustang
4925
95.0
4887
94.0
5087
96.0
4966
95.0
Herbicides
Weedmaster
4818
93.0
4533
87.2
4900
92.4
4750
90.9
Sunsac
5121
98.8
4883
93.9
4933
93.1
4979
95.3
Secator
4900
94.7
5167
99.4
5000
94.3
5025
96.1
Logran
3909
75.4
4750
91.3
3700
70.1
4120
78.8
Lintur
4795
92.5
4950
95.2
5034
95.0
4924
94.2
Akurat
4879
94.1
4888
94.0
5066
95.6
4948
94.6
Akurat extra
4925
95.0
4871
93.7
5000
94.3
4927
94.3
Eagle
4727
91.2
4633
89.1
4867
91.8
4742
90.7
Herbaflex
4864
93.8
4900
94.2
4733
89.3
4832
92.4
Starane
4909
94.7
5005
96.3
5200
98.1
5038
96.4
Sanafen
4727
91.2
4700
90.4
4933
93.1
4787
91.6
Dicotex
4879
94.1
4950
95.2
4958
93.6
4929
94.3
Herby
5091 373 481 606
98.2 7.2 9.3 11.7
4888 322 428 555
94.0 6.2 8.2 10.7
4967 345 426 522
93.7 6.5 8.0 9.9
4982
95.3
LSD 5% LSD 1 % LSD 0.1%
34
Weather conditions during the three years included in the investigation, were significantly different between them. Significant differences between years were very favorable for evaluation of investigated antibroadleaved herbicides.
Table 8 Analysis of variance for grain yield Source of variation
Degrees of freedom
Sum of squares
Influence of factor, %
Mean squares
Total
188
138091
100
-
Tract of land
2
40989
1.5
139601***
Variants
62
398960
96.4
31570.7***
2
198192
37.0
29362.8***
20
176851
34.8
31320.8***
40
163283
24.6
27756.7**
124
51611
2.1
304.0
Factor A – Years Factor B – Herbicides AxB Pooled error *p5%
**p1%
***p0,1%
Analysis of variance for grain yield (Table 8) shows that investigated variants have proven influence on grain yield – 96.4 %. The years have the highest influence on grain yield – 37.0 % on the variants. It is determined by unequal response of variants to changes in environmental conditions. The reason is the large differences in the meteorological conditions during the three years of investigation. The strength of influence of investigated herbicides is 34.8 %. The influence of years and preparations is well proven at p 0.1. There is an interaction between herbicides and meteorological conditions of years (AxB) – 24.6 %. It is well proven at p 0.1. That means that some of herbicides Granstar, Granstar super, Ally max, Arat, Biathlon, Derby super, Mustang, Weedmaster, Sunsac, Secator,
35
Logran, Lintur, Akurat, Akurat extra, Eagle, Herbaflex, Starane, Sanafen, Dicotex and Herby, applied during the 2-nd stem node stage of durum wheat, have negative influence on grain yield which depends on different weather conditions in the particular years. Based on proven preparation x year interaction, it was evaluated stability parameters for each variant for grain yield of durum wheat with relation to years (Table 9). It was calculated the stability variances ıi2 and Si2 of Shukla, the ecovalence Wi of Wricke and the stability criterion YSi of Kang. Stability variances (ıi2 ɢ Si2) of Shukla, which recorded respectively linear and nonlinear interactions, unidirectional evaluate the stability of the variants. These variants which showed lower values are considered to be more stable because they interact less with the environmental conditions. Negative values of the indicators ıi2 and Si2 are considered 0. At high values of either of the two parameters - ıi2 and Si2, the variant are regarded as unstable. At the ecovalence Wi of Wricke, the higher are the values of the index, the more unstable is the variant. On this basis, using the first three parameters of stability, it is found that during 2-nd stem node stage of durum wheat the most unstable are herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Eagle, Herbaflex and Herby, followed by Mustang, Sanafen and Dicotex. At herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Eagle, Herbaflex and Herby values of stability variance ıi2 and Si2 of Shukla and ecovalence Wi of Wricke are the highest and mathematically proven. Instability is a linear type and a nonlinear type - proven values of ıi2 and Si2. At herbicides Mustang, Sanafen and Dicotex instability is a linear type - proven values of ıi2, the values of Si2 are not proven. The reason for this high instability is greater variation in grain yields during years of 36
Table 9 Stability parameters of herbicides for grain yield with relation to years at treatment during 2-nd stem node stage ത
ıi2
Si2
Wi
YSi
Check
5227
203.7
5.8
402.6
22+
Granstar
4635
473.0**
1050.0**
1006.5
-9
Granstar super
4647
455.3***
48.7***
912.7
-5
Ally max
4642
499.7***
42.6***
963.8
-5
Arat
4987
207.0
100.0
502.3
18+
Biathlon
4945
358.2
75.3
669.1
18+
Derby super
5003
240.5
29.5
470.5
20+
Mustang
4913
200.8*
403.9
411.1
6
Weedmaster
4750
618.4
-7.0
404.4
-4
Sunsac
4630
128.2**
209.4**
204.2
-8
Secator
4982
42.0
72.1
94.7
15+
Logran
4120
598.6***
187.0***
837.6
-8
Lintur
4924
111.9
86.6
295.7
14+
Akurat
4948
100.5
47.0
200.4
15+
Akurat extra
4927
99.9
59.8
222.5
13+
Eagle
4742
246.2***
186.2***
481.3
-3
Herbaflex
4832
336.3**
81.2**
648.8
-7
Starane
5038
100.9
30.6
105.7
6
Sanafen
4787
218.4*
-0.8
244.6
5
Dicotex
4929
300.2*
55.5
533.2
3
Herby
4982
236.0*
70.2*
548.8
0
Herbicides
experience as weather conditions affect those most. Other ninth herbicides Arat, Biathlon, Derby super, Weedmaster, Secator, Lintur, Akurat, Akurat extra and Starane exhibit high stability because they interact poorly with
37
the conditions of years. At herbicide Weedmaster however high stability has always been connected with the low grain yields during this stage. To evaluate the complete efficacy of each herbicide should be considered as its effect on grain yield of durum wheat and its stability - the reaction of wheat to this variant during the years. Valuable information about the value of technologic value of the variant give the stability criterion YSi of Kang for simultaneous assessment of yield and stability, based on the reliability of the differences in yield and variance of interaction with the environment. The value of this criterion is experienced that using nonparametric methods and warranted statistical differences we get a summary assessment aligning variants in descending order according to their economic value. Generalized stability criterion YSi of Kang, taking into accounts both the stability and value of yields gives a negative assessment of herbicides Granstar, Granstar super, Ally max, Sunsac, Weedmaster, Logran, Eagle and Herbaflex, characterizing them as the most unstable and low yields. Herbicides Granstar, Granstar super, Ally max and Sunsac, receive low estimates due to their high instability during different meteorological conditions. Herbicides Weedmaster, Logran, Eagle and Herbaflex receive low estimates due to their high phytotoxicity to durum wheat during applying in 2-nd stem node stage of durum wheat. Herbicide Herby receives estimate 0. According to this criterion, during treatment in 2-nd stem node stage of durum wheat, technologically the most valuable appears herbicides Derby super, Arat, Biathlon, Secator, Akurat, Akurat extra and Lintur. These herbicides combine high levels of grain yield and high stability of this index during the years. From the viewpoint of technology for durum wheat growing, during 2-nd stem node stage good estimates have also 38
herbicides Mustang, Starane, Dicotex and Sanafen. These herbicides combine good levels of grain yield and good stability of this index during the years.
1.3. Grain yields. Stability and technological value of yields during 3-rd stem node stage Data about the influence of investigated antibroadleaved herbicides on grain yield are showed that herbicides Arat, Biathlon, Derby super, Secator, Lintur, Akurat, Akurat extra and Starane, applied during 3-rd stem node stage of durum wheat have not proved decrease on grain yield (Table 10). At herbicides Granstar, Granstar super, Ally max, Mustang, Weedmaster and Sunsac is remained the same trend - an increase of phytotoxicity and a decrease of grain yield from 592 kg/ha to 663 kg/ha or from 11.3 % to 12.7 %. The decrease of the grain yield by treatment with herbicides Granstar, Weedmaster and Sunsac during 3-rd stem node stage is proven during each year, regardless of weather conditions. At herbicides Granstar super, Ally max and Mustang decrease of the yield is reported only during certain years. Hormone-similar herbicides Sanafen, Dicotex and Herby as well as Logran, Eagle and Herbaflex also have phytotoxicity on the durum wheat. The biggest is the negative effect at the herbicide Logran where the decrease of grain yield in relative to the control is up to 1911 kg/ha during 2012 or 36.9 %. 3-rd stem node stage is the first stage during which the herbicides Mustang, Dicotex and Herby appear phytotoxicity to durum wheat. During
39
1-st and 2-nd stem node stages these three herbicides appear good selectivity for durum wheat.
Table 10 Grain yield of durum wheat at treatment during 3-rd stem node stage (2012 2014)
Check
2012 kg/ha % 5184 100
2013 kg/ha % 5199 100
2014 kg/ha % 5299 100
Mean kg/ha % 5227 100
Granstar
4636
89.5
4767
91.7
4500
84.9
4635
88.7
Granstar super
4666
90.0
4767
91.7
4504
85.0
4647
88.9
Ally max
4636
89.5
4783
92.0
4504
85.0
4642
88.8
Arat
4879
94.1
5100
98.1
4981
94.0
4987
95.4
Biathlon
4868
93.9
4933
94.9
5034
95.0
4945
94.6
Derby super
4909
94.7
4933
94.9
5167
97.5
5003
95.7
Mustang
4879
94.1
4833
92.9
5034
95.0
4913
94.0
Herbicides
Weedmaster
4758
91.8
4500
86.5
4433
83.6
4564
87.3
Sunsac
4758
91.8
4833
92.9
4300
81.1
4630
88.6
Secator
4879
94.1
5100
98.1
4967
93.7
4982
95.3
Logran
3273
63.1
4400
84.6
3433
64.8
3702
70.8
Lintur
4879
94.1
4903
94.3
5029
94.6
4929
94.3
Akurat
4868
93.9
4835
93.0
5045
95.2
4913
94.0
Akurat extra
4900
94.5
4835
93.0
4981
94.0
4903
93.8
Eagle
4727
91.2
4500
86.5
4833
91.2
4687
89.6
Herbaflex
4818
93.0
4350
83.6
4567
86.2
4578
87.6
Starane
4849
93.6
4907
94.4
5067
95.6
4941
94.5
Sanafen
4666
90.0
4600
88.5
4767
90.0
4798
89.5
Dicotex
4879
94.1
4800
92.3
4700
88.7
4793
91.7
Herby
4818 350 466 603
93.0 6.7 9.1 11.6
4733 339 432 565
91.0 6.6 8.2 10.8
4900 374 487 598
92.4 7.0 9.1 11.1
4817
92.1
LSD 5% LSD 1 % LSD 0.1%
40
Weather conditions during the three years included in the investigation, were significantly different between them. Significant differences between years were very favorable for evaluation of investigated antibroadleaved herbicides.
Table 11 Analysis of variance for grain yield Source of variation
Degrees of freedom
Sum of squares
Influence of factor, %
Mean squares
Total
188
138088
100
-
Tract of land
2
40999
1.6
13966.1***
Variants
62
398970
96.5
31572.0***
2
198201
36.9
29364.2***
20
176862
35.0
31323.3***
40
163290
24.6
27756.6**
124
51601
1.9
303.2
Factor A – Years Factor B – Herbicides AxB Pooled error *p5%
**p1%
***p0,1%
Analysis of variance for grain yield (Table 11) shows that investigated variants have proven influence on grain yield – 96.5 %. The years have the highest influence on grain yield – 36.9 % on the variants. It is determined by unequal response of variants to changes in environmental conditions. The reason is the large differences in the meteorological conditions during the three years of investigation. The strength of influence of investigated herbicides is 35.0 %. The influence of years and preparations is well proven at p 0.1. There is an interaction between herbicides and meteorological conditions of years (AxB) – 24.6 %. It is well proven at p 0.1. That means that some of herbicides Granstar, Granstar super, Ally max, Arat, Biathlon, Derby super, Mustang,
41
Weedmaster, Sunsac, Secator, Logran, Lintur, Akurat, Akurat extra, Eagle, Herbaflex, Starane, Sanafen, Dicotex and Herby, applied during the 3-rd stem node stage of durum wheat, have negative influence on grain yield which depends on different weather conditions in the particular years. Based on proven preparation x year interaction, it was evaluated stability parameters for each variant for grain yield of durum wheat with relation to years (Table 12). It was calculated the stability variances ıi2 and Si2 of Shukla, the ecovalence Wi of Wricke and the stability criterion YSi of Kang. Stability variances (ıi2 ɢ Si2) of Shukla, which recorded respectively linear and nonlinear interactions, unidirectional evaluate the stability of the variants. These variants which showed lower values are considered to be more stable because they interact less with the environmental conditions. Negative values of the indicators ıi2 and Si2 are considered 0. At high values of either of the two parameters - ıi2 and Si2, the variant are regarded as unstable. At the ecovalence Wi of Wricke, the higher are the values of the index, the more unstable is the variant. On this basis, using the first three parameters of stability, it is found that during 3-rd stem node stage of durum wheat the most unstable are herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Eagle, Herbaflex and Herby, followed by Mustang, Sanafen and Dicotex. At herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Eagle, Herbaflex and Herby values of stability variance ıi2 and Si2 of Shukla and ecovalence Wi of Wricke are the highest and mathematically proven. Instability is a linear type and a nonlinear type - proven values of ıi2 and Si2. At herbicides Mustang, Sanafen and Dicotex instability is a linear type - proven values of ıi2, the values of Si2 are not proven. The reason for this high instability is greater variation in grain yields during years of 42
Table 12 Stability parameters of herbicides for grain yield with relation to years at treatment during 3-rd stem node stage ത
ıi2
Si2
Wi
YSi
Check
5227
203.7
5.8
402.6
22+
Granstar
4635
573.0**
1150.0**
1086.5
-10
Granstar super
4647
563.0***
35.9***
1058.7
-5
Ally max
4642
560.7***
12.6***
1063.8
-6
Arat
4987
200.7
100.5
497.3
17+
Biathlon
4945
400.3
85.7
744.0
16+
Derby super
5003
230.3
21.8
452.1
19+
Mustang
4913
213.8*
443.9
421.4
5
Weedmaster
4564
718.4
-0.8
444.6
-5
Sunsac
4630
118.2**
239.4**
244.4
-9
Secator
4982
72.1
82.8
104.4
14+
Logran
3702
573.0**
1150.0**
1086.5
-10
Lintur
4929
151.9
106.6
395.7
10+
Akurat
4913
120.0
49.9
210.4
14+
Akurat extra
4903
111.9
70.8
234.0
12+
Eagle
4687
146.2***
86.2***
381.3
-5
Herbaflex
4578
118.2**
239.4**
244.4
-9
Starane
4941
91.9
36.6
195.7
4
Sanafen
4798
307.8*
630.5
595.5
-3
Dicotex
4793
328.2*
65.3
633.2
0
Herby
4817
336.3**
81.2**
648.8
-1
Herbicides
experience as weather conditions affect those most. Other ninth herbicides Arat, Biathlon, Derby super, Weedmaster, Secator, Lintur, Akurat, Akurat extra and Starane exhibit high stability because they interact poorly with
43
the conditions of years. At herbicide Weedmaster however high stability has always been connected with the low grain yields during this stage. To evaluate the complete efficacy of each herbicide should be considered as its effect on grain yield of durum wheat and its stability - the reaction of wheat to this variant during the years. Valuable information about the value of technologic value of the variant give the stability criterion YSi of Kang for simultaneous assessment of yield and stability, based on the reliability of the differences in yield and variance of interaction with the environment. The value of this criterion is experienced that using nonparametric methods and warranted statistical differences we get a summary assessment aligning variants in descending order according to their economic value. Generalized stability criterion YSi of Kang, taking into accounts both the stability and value of yields gives a negative assessment of herbicides Granstar, Granstar super, Ally max, Sunsac, Weedmaster, Logran, Herbaflex, Eagle, Sanafen and Herby, characterizing them as the most unstable and low yields. These tenth herbicides receive low estimates due to their high phytotoxicity to durum wheat during applying in 3-rd stem node stage of durum wheat. for durum wheat. Herbicide Dicotex receives estimate 0. According to this criterion, during treatment in 3-rd stem node stage of durum wheat, technologically the most valuable appears herbicides Derby super, Arat, Biathlon, Secator, Akurat, Akurat extra and Lintur. These herbicides combine high levels of grain yield and high stability of this index during the years. From the viewpoint of technology for durum wheat growing, during 3-rd stem node stage positive estimates have also herbicides Mustang and Starane. These herbicides combine good levels of grain yield and comparatively good stability of this index during the years. 44
1.4. Grain quality indicators Durum wheat is the main raw material for the production of high quality pasta. To meet this requirement, it must be grown in suitable agrotechnology, providing a high-quality grain. From this perspective, the efficient and timely displayed weed control in durum wheat crops is important for improving the quality of the durum wheat grain. The high selectivity of the herbicides used in the cultivation of durum wheat also has a positive impact on these indicators. The lowest values of 1000 grain weight are accounted in use of herbicides Weedmaster, Logran, Herbaflex and Eagle when they applied during early stem elongation stage (Tables 13, 14 and 15). The delay in treatment of herbicides - from 1-st to 3-rd stem nodes of durum wheat - leads to a small increase of 1000 grain weight at herbicides Granstar, Granstar super, Ally max, Eagle, Starane, Herbaflex, Dicotex and Herby. The reason for this increase is the smaller number of grains in the spike of main tiller. The indicator values are not changed by use of herbicides Arat, Biathlon, Derby super, Mustang, Sunsac, Secator, Akurat, Akurat extra, Lintur and Starane. Only herbicides Weedmaster and Logran by treatment in stem elongation stage of durum wheat always lead to mathematically proven decrease of 1000 grain weight. Test weight characterizes the density of the grain and is one of the important technological parameters. Usually with increasing nitrogen rate specific weight decreases. This is associated with the preparation of a more lax tissue cell at a high nitrogen fertilizer, especially under dry conditions. Uses of investigated antibroadleaved herbicides not adversely affect the test weight of the grain. It retains its high levels characteristic of durum wheat all variants except weeded control have test weight over 82 kg. 45
Table 13 Grain quality of durum wheat at treatment during 1-st stem node stage (2012 - 2014) Gluten
Herbicides
1000 grain weight, g
Test weight, kg
Vitreousness, %
Protein, %
Check Granstar Granstar super Ally max Arat Biathlon Derby super Mustang Weedmaster Sunsac Secator Logran Lintur Akurat Akurat extra Eagle Herbaflex Starane Sanafen Dicotex Herby LSD 5% LSD 1% LSD 0.1%
48.8 48.0 48.0 48.1 48.7 48.6 48.2 48.4 46.8 48.0 48.6 47.4 48.2 48.4 48.7 47.8 47.6 46.4 48.2 48.4 48.2 1.5 2.4 3.2
82.3 82.7 82.7 82.7 82.6 82.6 82.5 82.5 82.8 82.3 82.1 82.0 82.2 82.0 81.9 82.3 82.2 82.4 82.1 82.2 82.0 1.4 2.0 3.4
95.0 94.8 94.5 94.5 94.6 94.6 94.4 94.4 95.4 93.4 94.4 93.8 94.4 94.5 94.5 95.2 94.2 94.2 93.8 93.4 94.6 1.9 2.4 4.2
18.13 18.31 18.16 18.17 18.20 18.21 18.16 17.98 17.63 17.37 18.17 18.13 18.12 19.00 18.98 18.56 17.71 17.19 18.14 19.04 18.48 0.30 0.37 0.44
Wet %
Dry %
39.6 39.2 39.6 32.4 39.5 39.5 39.8 39.0 38.2 39.8 39.8 39.6 39.2 40.6 40.4 39.2 37.6 36.8 36.8 40.4 41.6 0.7 1.9 2.8
14.9 14.7 14.9 14.7 14.5 14.6 14.9 14.7 14.6 14.6 14.7 14.9 15.2 15.2 15.2 15.2 14.1 13.7 13.8 15.2 15.6 0.4 1.0 1.5
The use of antibroadleaved herbicides does not lead to proven decreases virteousness of durum wheat grain, although this was some variation during years.
46
Table 14 Grain quality of durum wheat at treatment during 2-nd stem node stage (2012 - 2014)
Herbicides
1000 grain weight, g
Check Granstar Granstar super Ally max Arat Biathlon Derby super Mustang Weedmaster Sunsac Secator Logran Lintur Akurat Akurat extra Eagle Herbaflex Starane Sanafen Dicotex Herby LSD 5% LSD 1% LSD 0.1%
48.8 48.2 48.3 48.5 48.6 48.6 48.4 48.7 46.4 48.2 48.6 46.2 48.7 48.8 48.7 48.2 48.0 47.2 48.4 48.8 48.6 2.0 3.2 4.4
Gluten VitreousTest weight, ness, kg % 82.3 82.3 82.3 82.2 82.2 82.2 82.2 82.3 82.6 82.5 82.2 82.2 82.2 82.2 82.4 82.3 82.1 82.3 82.1 82.4 82.4 1.6 2.3 3.6
95.0 94.0 94.0 94.0 93.8 93.8 93.8 93.7 94.4 93.2 93.6 93.6 93.4 93.6 93.5 95.0 94.6 94.6 93.4 93.6 93.4 2.1 2.9 4.5
Protein, %
18.13 18.73 18.70 18.69 18.67 18.67 18.80 17.88 16.86 17.88 18.71 17.79 18.14 19.19 18.22 18.05 18.31 17.79 18.39 18.14 18.14 0.28 0.32 0.40
Wet %
Dry %
39.6 39.2 39.1 39.0 39.2 39.2 39.9 39.4 37.6 40.0 39.9 39.6 40.0 40.4 40.4 38.8 38.2 38.0 40.4 38.8 40.4 1.0 2.1 3.3
14.9 14.7 14.6 14.6 14.5 14.4 14.9 14.8 14.6 14.5 14.8 14.9 14.0 14.6 14.2 15.0 14.6 14.2 14.6 14.6 14.2 0.5 1.3 2.4
The keeping the physics properties of the grain (1000 grain weight, test weight and virteousness) high and stable guaranteed good mill qualities and high semolina output.
47
Table 15 Grain quality of durum wheat at treatment during 3-rd stem node stage (2012 - 2014)
Herbicides
1000 grain weight, g
Check Granstar Granstar super Ally max Arat Biathlon Derby super Mustang Weedmaster Sunsac Secator Logran Lintur Akurat Akurat extra Eagle Herbaflex Starane Sanafen Dicotex Herby LSD 5% LSD 1% LSD 0.1%
48.8 48.6 48.7 48.8 48.6 48.6 48.6 48.7 46.2 48.2 48.8 48.8 46.0 48.8 49.0 49.0 48.8 49.0 48.0 48.6 49.0 2.9 3.8 5.0
Gluten VitreousTest weight, ness, kg % 82.3 82.0 82.0 82.0 82.2 82.2 82.2 82.1 82.6 82.0 82.2 82.3 82.4 82.0 82.3 82.3 82.3 82.1 82.0 82.0 82.3 1.9 3.1 4.5
95.0 93.4 93.4 93.4 93.3 93.3 93.6 93.5 94.4 93.0 93.6 95.0 93.2 93.2 94.4 93.4 95.0 94.6 94.8 94.4 93.2 2.0 2.8 4.2
Protein, %
18.13 19.76 19.77 19.78 18.55 18.55 18.97 17.80 16.85 18.05 18.99 18.13 17.36 17.80 19.42 17.82 17.62 18.82 18.13 19.42 17.80 0.22 0.31 0.43
Wet %
Dry %
39.6 46.0 46.0 46.0 39.8 39.8 39.6 39.6 35.6 41.2 39.8 39.6 39.6 38.8 43.6 38.8 38.8 40.8 40.8 43.6 38.8 1.2 2.4 3.6
14.9 16.1 16.1 16.1 15.0 15.0 14.9 14.7 13.4 15.5 14.9 14.9 14.9 14.6 15.3 14.1 14.6 15.3 14.8 15.3 14.6 0.6 1.5 2.7
Other indexes included in the investigation characterized the biochemical properties of the grain from the different variants as raw material for the pasta production. The protein quantity and the wet and dry gluten quantities are one of the most important indexes, leading to pasta with a good culinary quality.
48
The protein quantity is definitely by cultivar, but it varies depending on weather conditions and the agrotechnology. In this sense it is necessary to note that later treatment -from 1-st to 3-rd stem nodes of durum wheat with herbicides Granstar, Granstar super, Ally max, Sunsac, Derby super, Secator, Starane, Herbaflex and Sanafen leads to prove increase of protein quantity. At herbicides Granstar, Granstar super, Ally max, Sunsac, Herbaflex and Sanafen this increase can be explained by the significantly lower grain yields, which are obtained by these variants, as a result of the existing negative correlation between quantity and quality of yield. At herbicides Arat, Biathlon, Derby super, Secator, Akurat and Starane protein quantity has increased, although the yield of grain does not change proven by treatment with these herbicides during stem elongation stage. Other herbicides included in investigation - Mustang, Weedmaster, Logran, Lintur, Akurat extra, Eagle, Decotex and Herby - decrease protein quantity. Wet and dry gluten quantities are an important element of the quality characteristics of the grain. The obtained data show that late treatment with herbicides Sunsac, Starane, Herbaflex and Sanafen leads to increase of wet and dry gluten quantities. These quantities decreased by treatment with herbicides Weedmster, Mustang, Eagle, Dicotex and Herby. Herbicides Arat, Biathlon, Derby super, Secator and Logran do not change wet and dry gluten quantities. Herbicides Granstr, Granstar super, Ally max and Akurat do not change wet and dry gluten quantities at treatment during 1-st and 2-nd stem node stages, but increase these quantities at treatment during 3-rd stem node stage of durum wheat. All variants are over the standard requirements about the wet gluten quantity - more than 28 %. The ratio between wet and dry gluten (2.5 - 3 to 1) remains unchanged and favorable for producing high quality pasta.
49
The differences in the biochemical properties of the grain are due to the changes in the speed and nature of the physiological and biochemical processes in plants occurring under the influence of different herbicides.
1.5. Sowing characteristics of seeds One of the important conditions for obtaining a normal crop and a good harvest is the use of quality seeds. Apart from the high-yield cultivar which is resistance to diseases and pests, it must have the necessary sowing properties, the main of which are high germination energy and seed germination. Germination energy is one of the most important characteristics of the sowing properties of the seed. The low germination energy is the reason for slower development of primary roots and coleoptile after seed germination and is associated with later germination in field conditions, less tempering of plants and a higher risk of frost in the winter. Its lead to lower grain yields. The obtained results (Tables 16, 17 and 18) show that none of investigated herbicides at treatment during 1-st stem node stage of durum wheat influence proven on this index. Herbicides Granstar, Granstar super, Ally max, Weedmaster, Logran and Eagle at treatment during 2-nd stem node stage of durum wheat lead to decrease in the germination energy of seeds. At treatment during 3-rd stem node stage of durum wheat germination energy is decreased not only by influence of these six herbicides, but also by influence of herbicides Sunsac and Herbaflex. Germination is the most important index who characterizing the sowing properties of the seed. At low laboratory germination sowing should be done with higher sowing rate, which increases the cost production. Laboratory germination of the seeds by treatment during 1-st 50
Table 16 Sowing characteristics of durum wheat seeds at treatment during 1-st stem node stage (2012 - 2014) Length, cm Herbicides
Check Granstar Granstar super Ally max Arat Biathlon Derby super Mustang Weedmaster Sunsac Secator Logran Lintur Akurat Akurat extra Eagle Herbaflex Starane Sanafen Dicotex Herby LSD 5% LSD 1% LSD 0.1%
Germination energy, %
Seed germination %
Coleoptile
Root
Waste grain, %
96.0 91.0 91.5 91.5 96.5 97.0 98.0 97.0 95.0 95.5 99.0 95.0 95.5 96.5 95.0 92.5 97.0 98.0 96.0 99.5 98.5 5.8 7.2 8.3
99.0 96.6 96.5 96.5 98.0 98.5 99.0 99.0 96.5 98.0 99.0 96.0 97.5 97.5 97.0 97.0 97.0 99.0 97.0 99.5 98.0 4.6 5.9 7.4
11.56 10.03 10.05 10.65 10.85 10.98 11.54 10.60 10.62 11.50 11.44 11.09 10.82 10.93 10.95 10.69 10.89 10.16 10.20 10.20 10.20 2.1 4.8 6.2
18.01 18.09 18.07 18.02 18.06 18.06 18.06 18.00 18.02 18.18 18.44 17.96 17.86 17.90 18.00 17.93 17.16 18.04 18.03 18.03 18.03 3.3 5.9 8.1
7.8 8.1 8.1 8.1 8.0 8.0 7.1 7.8 8.1 8.1 7.6 8.3 7.8 7.3 7.6 8.9 7.6 8.4 7.8 7.3 7.6 1.3 2.6 4.3
stem node stage of durum wheat at all variant is above the requirements of the standard for over 85% germination, although in different years account for some variation of its values. Herbicides Granstar, Granstar super, Ally max, Weedmaster, Logran and Herbaflex at treatment during 2-nd stem node stage of durum wheat are unproven decrease seed germination – decreasing is from 5 % to 9 %. Uses 51
Table 17 Sowing characteristics of durum wheat seeds at treatment during 2-nd stem node stage (2012 - 2014) Herbicides
Check Granstar Granstar super Ally max Arat Biathlon Derby super Mustang Weedmaster Sunsac Secator Logran Lintur Akurat Akurat extra Eagle Herbaflex Starane Sanafen Dicotex Herby LSD 5% LSD 1% LSD 0.1%
Length, cm Seed Germination energy, germination, ColeopRoot % % tile 96.0 86.0 86.5 86.5 96.0 96.5 97.0 96.5 87.0 95.0 98.0 88.0 94.5 97.0 95.5 87.0 94.0 97.0 95.5 96.0 93.5 5.7 7.1 8.2
99.0 91.0 92.0 92.5 98.0 98.5 99.0 98.0 90.0 98.0 98.5 92.0 98.0 99.0 96.5 96.0 94.0 99.0 96.5 98.0 96.5 4.5 5.8 7.3
11.56 9.02 9.04 9.64 10.84 10.97 11.53 10.58 9.61 11.49 11.42 9.08 10.80 10.91 10.94 9.68 10.88 10.17 10.19 10.21 10.22 2.0 4.6 6.0
18.01 16.08 16.06 16.00 18.00 18.07 18.05 18.08 16.50 18.06 18.05 16.90 17.83 17.88 18.01 16.90 17.17 18.03 18.04 18.06 18.05 2.1 5.0 7.2
Waste grain, % 7.8 10.8 10.6 10.6 8.0 8.0 7.8 7.9 11.9 8.6 8.5 8.6 8.8 8.5 8.6 11.9 8.8 10.3 9.1 10.3 9.1 1.2 2.5 4.2
of the same herbicides during 3-rd stem node stage also decrease seed germination, but the negative effect is more intense - from 9 % to 14%. This is negative effect of their use, because it is necessary to the sowing rate (in kg/ha). This also increases the cost of necessary seeds and reduces economic effects of the durum wheat cultivation.
52
Table 18 Sowing characteristics of durum wheat seeds at treatment during 3-rd stem node stage (2012 - 2014) Herbicides
Check Granstar Granstar super Ally max Arat Biathlon Derby super Mustang Weedmaster Sunsac Secator Logran Lintur Akurat Akurat extra Eagle Herbaflex Starane Sanafen Dicotex Herby LSD 5% LSD 1% LSD 0.1%
Length, cm Seed Germination energy, germination, ColeopRoot % % tile 96.0 78.0 78.0 78.0 96.0 96.5 97.0 95.5 81.0 90.5 93.5 95.0 95.5 96.5 95.0 86.5 93.0 98.0 96.0 99.5 98.5 5.5 6.9 8.0
99.0 88.0 89.5 89.5 98.0 98.5 99.0 98.0 86.0 98.0 98.5 96.0 97.5 97.5 97.0 97.0 93.0 99.0 97.0 99.5 98.0 4.4 5.7 7.3
11.56 8.83 8.85 9.24 10.80 10.95 11.52 10.55 9.42 11.46 11.40 9.08 10.78 10.90 10.93 9.67 10.78 10.16 10.17 10.20 10.20 2.2 4.7 6.1
18.01 16.00 16.01 16.00 18.06 18.02 18.04 18.07 16.39 18.02 18.03 16.90 17.82 17.86 18.00 16.69 17.15 18.02 18.03 18.05 18.04 2.0 5.1 7.3
Waste grain, % 7.8 11.2 11.0 11.0 8.9 8.9 8.7 8.0 14.1 9.4 8.9 7.8 8.8 8.8 8.7 8.7 13.4 11.6 12.7 9.4 12.8 1.4 2.7 4.4
Herbicides Sunsac and Eagle although decrease germination energy by treatment during stage 3-rd stem node stage, not have proven inhibitory effect on laboratory seed germination. Under influence of these two herbicides seeds germinate normally, although their initially pace of development is weak due to weaker germination energy.
53
The obtained results for germination energy and seed germination are a prerequisite continue to investigate the effect of herbicides on initial intensity of the growth of seeds, expressed by the length of roots. It was found that the length of coleoptiles and coleoptiles of durum wheat is decreased by Granstar, Granstar super, Ally max, Weedmaster, Logran and Eagle. The decreasing is proven by analysis of variants. These herbicides difficult young plants developments, reduces their resistance to cold and increase risk of frost damages during winter months. Other herbicides have not negative effect on the growth of the length of primary roots and coleoptiles of the durum wheat and recommended for use in seed production crops of durum wheat. At the evaluation of the sowing characteristics we have to consider not only the characteristics of the sowing seeds but also the quantity of the waste grain (siftings) which are gained at the preparation of these seeds. Bigger quantity screenings lead to higher cost of the seed and reduce the economic effect of seed production of durum wheat. The obtained results show that none of investigated herbicides at treatment during 1-st stem node stage of durum wheat change the quantity of the waste grain. Herbicides Granstar, Granstar super, Ally max, Weedmaster, Eagle, Starane, Sanafen, Dicotex and Herby at treatment during 2-nd and 3-rd stem node stages of durum wheat increase the quantity of the waste grain. Herbicides Sunsac and Herbaflex increase the quantity of the waste grain only at treatment during 3-rd stem node stage of durum wheat. Herbicide Logran although has high depressing influence on germination energy and laboratory germination of seeds does not increase proven quantity of received screenings. On the other hand, herbicide Starane and three hormone-similar herbicides - Sanafen, Dicotex and 54
Herby, although not influence on germination energy and seed germination, increase proven waste grain quantity. Herbicides Arat, Biathlon, Derby super, Mustang, Secator, Akurat, Akurat extra and Lintur lead to slight changes in the values of the investigated indices - germination energy, laboratory germination and quantity of waste grain which do not prove mathematically at analysis of variance. Decreases in the values of germination energy and laboratory seed germination, changes in the intensity of the initial growth, expressed by the length of the root and coleoptile at germination and changes in the quantity of waste grain under the influence of investigated herbicides are explained by the depressing effects on growth and development of the durum wheat during its vegetative period.
55
2. CHANGES IN OVER-GROUND PART AND PRODUCTIVITY OF DURUM WHEAT BY LATE TREATMENT WITH ANTIGRAMINACEOUS HERBICIDES 2.1. Changes in leaf area For exploration the possibilities to fight with secondary weed infestation with graminaceous weeds in durum wheat fields for processing and for seed production it was carried out a two factor experiment. Factor A included 2 Bulgarian durum wheat cultivars - Progress, which belongs to var. leucurum and Vuzhod, which belongs to var. valenciae. Factor B included no treated control and 4 herbicides: Puma super, Grasp, Topik and Hussar max. The active substances and doses of the investigated herbicides are described in detail in Table 2 of the Material and Methods section. The weak adhesion of Grasp and Hussar max required their application with adjuvant - accordingly Atplus and Genapol. All herbicides were treated during 1-st, 2-nd and 3-rd stem node stages of durum wheat. To examine only the influence of herbicides and eliminate the negative influence of weeds they are removed by hand weeding during the growing period. The obtained results (Table 19) show that from both tested cultivars, cultivar Progress formed a larger leaf area. In weeded control of this cultivar, the leaf area of the main tiller occupies 62 % of that of the whole plant. The second tiller occupies 33 %, and the other tillers 5 % of the total leaf area. In cultivar Vuzhod, the leaf area of the main tiller in the weeded control is slightly higher and represents 64 % of the plant leaf area. The
56
area of the second tiller is 32 % of that of the plant, and the leaf area of the other tillers - mainly third and fourth - is 4 %. Table 19 Leaf area index, m2/da (mean 2004 - 2006) Variant
Whole plant
Progress Main Second tiller tiller
Control
83040
51480
27410
Other tillers
Whole plant
Vuzhod Main Second tiller tiller
Other tillers
4150
74850
47910
23950
2990
44570
26010
3710
-st
1 stem node stage Puma super
82480
48640
28040
5800
74290
Grasp
82520
48680
28060
5780
74320
44590
25990
3740
Topik
82670
48770
28110
5790
73530
44120
25740
3670
Hussar max
82600
48750
28080
5810
73270
43970
25650
3650
2
-nd
stem node stage
Puma super
81650
48170
27760
5720
72790
43670
25480
3640
Grasp
81740
48220
27790
5780
72690
43590
25440
3660
Topik
81870
48300
27840
5730
72560
43540
25390
3630
Hussar max
81760
48240
27800
5720
72400
43440
25350
3610
3-rd stem node stage Puma super
80920
47740
27550
5630
71310
42770
24960
3580
Grasp
80710
47610
27440
566
71490
42870
25020
3600
Topik
80790
47680
27570
5700
71220
42730
24940
3550
80880
47720
27500
5660
71160
42700
24890
3570
3330 6330 8200
3440 6210 8370
1770 3010 4240
1020 2130 3550
4690 7850 9890
4910 7770 9120
1940 2980 3930
530 1800 3020
Hussar max LSD 5% LSD 1% LSD 0.1%
The plant leaf area index values of whole plant (the maximal leaf area formed by plant) in both cultivars practically do not change under the influence of the different herbicides applied during the same stage. All four used herbicides: Puma super, Grasp, Topic and Hussar max, decrease plant leaf area index of whole plant, especially when they are applied during 3-rd stem node stage, but the differences are not mathematically proven. The
57
distribution of the leaf area between the individual brethren inside the plant also changes. The distribution of the leaf area between the individual tillers in the plant also changes. For cultivar Progress the main tiller already occupies 59 %, the second tiller is 34 % and the other tillers 7 % of the total leaf area of the whole plant. For cultivar Vuzhod this ratio is 60 % for the main tiller, 35 % for the second tiller and 5 % for the other tillers. The total leaf area of main tiller decreases by treatment with each of the four herbicides during 3-rd stem node stage of both cultivars. In 1-st and 2-nd stem node stages, the trend to decreasing of leaf area index of main tiller is clearly visible but not mathematically proven. For the second tiller, there is an undetermined tendency to increase leaf area index versus control. For the other tillers mainly third and partly fourth - this increase is mathematically proven. This is explained by the plant's aspiration to compensate for the decrease of the leaf area of the main tiller whose growth is mostly strongly influenced by antigraminaceous herbicides. The increase in these tillers expressed in absolute values in m2/ha, however, is less than the decrease in the main tiller, resulting in a decrease in the total plant leaf area of these variants.
2.2. Plant height and biological yield The plant height changes under the influence of part of the tested herbicides (Table 20). Herbicide Puma super - during the three stages and herbicide Hussar max - only during 3-rd stem node, proven to reduce the height of the main and second tiller of cultivar Progress. The use of herbicide Topic during 3-rd stem node stage in this cultivar decreases the height of second tiller only, but not of main tiller (the central stem of the durum wheat). In cultivar Vuzhod only herbicide Puma super applied 58
Table 20 Stem height, biological and economical yield (mean 2004 - 2006) Variant
Progress Height, cm Dry biomass, Main Second kg/ha tiller tiller
Grain yield, kg/ha
Vuzhod Height, cm Dry biomass, Main Second kg/ha tiller tiller
Grain yield, kg/ha
Contol
99.7
4526
86.5
89.6
12713
75.5
12119
4569
1-st stem node stage Puma super
95.2
84.7
12720
4503
83.8
74.7
12391
4659
Grasp
98.5
87.5
12788
4526
83.5
73.8
12306
4627
Topik
98.7
87.8
12712
4500
84.8
74.7
12223
4596
Hussar max
97.5
85.3
12768
4520
84.5
74.8
12234
4600
2-nd stem node stage Puma super
94.7
83.2
12565
4455
83.2
73.7
12231
4599
Grasp
97.8
87.2
12664
4483
83.0
73.0
12112
4554
Topik
98.3
87.3
12542
4440
84.5
74.6
12146
4567
Hussar max
96.7
85.6
12641
4475
84.5
74.2
12088
4545
3-rd stem node stage Puma super
94.3
83.2
12552
4431
81.7
72.8
12107
4540
Grasp
96.5
84.8
12397
4376
82.3
72.2
11947
4480
Topik
96.5
83.8
12499
4412
83.5
73.5
12029
4511
94.8
82.7
12561
4434
83.3
73.7
11984
4494
4.7 8.0 11.1
5.6 7.8 9.9
666 983 1259
230 301 384
4.5 7.7 10.2
4.0 6.2 8.3
555 976 1234
218 280 363
Hussar max LSD 5% LSD 1% LSD 0.1%
during 3-rd stem node stage reduces the height of main tiller, but does not change the height of second tiller. Treating with these herbicides, although reducing the stem heigh, is not associated with negative effects on biological and economical yields. Therefore, they have a retardant and not phytotoxic effect on durum wheat. The other tillers - mainly third and sometimes fourth - do not form a true stem. The third tiller sometimes forms a low stem, which even less often ends with a small spike. However, it is infertile, contains a very small number of spikelets that are sterile and
59
do not form grains. These tillers have no influence on both the yield and the stability of the plants to lodging. The accumulation of dry biomass follows the formation of the leaf area. Variants with smaller leaf area are formed and less biomass. Generally cultivar Progress formed a larger biomass of cultivar Vuzhod. The differences between dry biomass in different variants are small and are within the error range. Grain yields also do not change under the influence of tested herbicides. Both of yields - biological and economical, there is a tendency to decrease from 1-st to 3-rd stem node stage, more pronounced in cultivar Progress. The use of herbicides is associated with a deterioration of grain: straw ratio. In cultivar Progress, this ratio is less favorable than cultivar Vuzhod. In Progress it is 1: 1.81, while in Vuzhod - 1: 1.65. The grain yield reduction increases the percentage of straw in dry biomass. Grain: straw ratio reflects on the harvest index - the ratio of grain yield to total plant biomass. Weeded control in Progress is characterized by a harvest index of 0.356, and in Vuzhod - of 0.377. It changes with the use of antigraminaceous herbicides during stem elongation stage. For cultivar Progress, the harvest index by treatment with Puma super, Grasp, Topic and Hussar max is 0.354 - 0.353 with grain ratio: straw 1: 1.83 - 1.84 and for cultivar Vuzhod the values are 0.376 - 0.375 and 1: 1.66 - 1.67. Lower yield variants are also characterized by a lower harvest index.
2.3. Grain yield The meteorological conditions in the three years included in the investigation, was very different between each other - the 2004 was with rains, that are average as quantity, the 2005 was with droughty in the end of 60
tillering stage of the durum wheat and in stem elongation stage as well, and the 2006 was very humid. Significance differences between years were opportune for estimate the efficiency to the investigated antigraminaceous herbicides (Table 21). The data for the influence of preparations – Puma
Table 21 Influence of the herbicides on grain yield, kg/ha (2004 - 2006) Progress Variant Contol
2011
2012
4444
5167
Vuzhod
2013
Mean
2011
2012
2013
Mean
3967
4526
4523
5333
3850
4569
1-st stem node stage Puma super
4450
5110
3950
4503
4666
5383
3927
4659
Grasp
4408
5200
3967
4525
4646
5367
3867
4627
Topik
4384
5183
3933
4500
4539
5400
3850
4596
Hussar max
4392
5200
3967
4520
4567
5333
3900
4600
2-nd stem node stage Puma super
4392
5067
3907
4455
4606
5333
3857
4599
Grasp
4365
5183
3900
4483
4545
5283
3833
4554
Topik
4321
5150
3850
4440
4551
5300
3850
4567
Hussar max
4376
5150
3900
4475
4507
5300
3827
4545
3
-rd
stem node stage
Puma super
4373
5033
3887
4431
4554
5233
3833
4540
Grasp
4244
5150
3733
4376
4500
5200
3740
4480
Topik
4269
5133
3833
4412
4492
5250
3790
4511
Hussar max
4312
5133
3857
4434
4483
5233
3767
4494
LSD, kg/ha: F. A p5%=36 F. B p5%=151 AxB p5%=228
p1%=47 p1%=181 p1%=271
p0.1%=62 p0.1%=218 p0.1%=323
61
super, Grasp, Topik and Hussar max on the grain yield show that they do not give negative effect on him and at the two durum wheat cultivars. The herbicide Grasp, treated in 3-rd stem node stage at cultivar Progress, leads to decrease of grain yield only, but it does not prove itself mathematically. The produced analysis of variance shows that from the general variation of the data, the years give most strong influence on the grain yield – 94.7 % (Table 22). Their action is showed at level of probability ɪ0.1 %. Cultivars give more strong influence - 4.1 % from the two factors of the
Table 22 Analysis of variance for grain yield Source of variation Total Years Variants Factor A-Cultivars Factor B-Herbicides AxB Pooled error *p5%
**p1%
Degrees of freedom
Sum of squares
Influence of factor, %
Mean squares
77
247135
100
-
2
240473
94.7
120236.5***
25
3606
4.1
144.2**
1
1828
1.7
1828.0**
12
1568
1.6
132.2
12
192
0.8
16.0
50
3056
1.2
61.1
***p0.1%
investigation. Influencing of herbicides is 1.6 %. The action of the variants as well this of cultivars is showed at level of probability ɪ1 %. Influencing the herbicides is unproved. Interaction did not exist as well between the cultivars (Factor A) and the herbicides (Factor B). This means that the investigated antigrass herbicides Puma super, Grasp, Topik and Hussar max treated in the 1-st, 2-nd in 3-rd stem node stage of the durum wheat do not show negative effect on the grain yield independently from the meteorological conditions in the different years for the investigation.
62
2.4. Structural elements of the yield The late treatment with antigraminaceous herbicides in stem elongation stage influence on the spike structural components as on the main tiller so on the second tiller as well. At cultivar Progress the spike length and the spikelets number of per the spike do not change (Table 23).
Table 23 Spike structural elements of the main and second tiller at cultivar Progress (mean 2004 - 2006) Main tiller Variant Check
Spike length,
Second tiller
cm
Spikelets per spike, number
Grain per spike, number
Grain weight per spike, g
Spike length, cm
Spikelets per spike, number
Grain per spike, number
Grain weight per spike, g
9.0
21.8
42.8
2.82
7.3
18.2
28.8
1.42
1-st stem node stage Puma super Grasp Topik Hussar max
8.9
21.0
40.2
2.74
7.2
18.0
28.0
1.44
9.0
21.6
42.2
2.78
7.3
18.2
28.6
1.42
8.9
20.8
40.0
2.72
7.2
17.8
27.8
1.46
8.9
21.2
41.8
2.74
7.2
18.0
27.8
1.48
2-nd stem node stage Puma super Grasp Topik Hussar max
8.7
20.2
37.6
2.36
7.0
17.4
27.6
1.64
8.9
20.9
39.8
2.40
7.1
17.6
28.0
1.60
8.7
20.2
37.4
2.32
6.9
17.2
27.8
1.66
8.8
20.6
38.6
2.38
7.0
17.4
27.8
1.62
3-rd stem node stage Puma super Grasp Topik Hussar max LSD 5% LSD 1% LSD0.1%
8.4
19.5
35.0
2.22
6.7
16.8
27.8
1.72
8.3
19.0
34.2
2.12
6.6
16.6
28.2
1.74
8.4
19.8
35.2
2.18
6.8
16.8
27.8
1.78
8.6
20.0
35.8
2.26
6.6
17.0
27.6
1.76
1.2 2.5 3.7
2.3 3.4 4.6
7.6 9.7 11.1
0.43 0.57 0.66
0.9 2.8 4.0
1.8 3.2 5.1
5.4 7.0 7.9
0.29 0.47 0.63
63
The use to Puma super, Grasp, Topik and Hussar max in the 3-rd stem node stage mathematically proved decrease to the grain number of per spike of the main tiller. Their number of the spike of the second tiller does not change. The use of the four herbicides in the 2-nd in 3-rd stem node stage decreases. The use to Puma super, Grasp, Topik and Hussar max in the 3-rd stem node stage in some time increases grain weight per spike of second tiller.
Table 24 Spike structural elements of the main and second tiller at cultivar Vuzhod (mean 2004 - 2006) Main tiller Variant Check
Second tiller
cm
Spikelets per spike, number
Grain per spike, number
Grain weight per spike, g
Spike length, cm
Spikelets per spike, number
Grain per spike, number
Grain weight per spike, g
8.2
20.4
46.8
2.52
6.1
17.2
2.0
0.82
Spike length,
1-st stem node stage Puma super Grasp Topik Hussar max
8.1
20.4
45.6
2.46
6.1
17.0
24.0
0.94
8.1
20.4
46.2
2.48
6.0
17.0
24.2
0.92
7.9
20.0
45.2
2.40
6.1
16.8
25.0
0.86
8.0
20.4
45.8
2.42
6.0
16.8
25.2
0.88
2-nd stem node stage Puma super Grasp Topik Hussar max
7.7
19.8
44.4
2.34
5.9
16.8
25.8
1.06
7.4
19.4
43.6
2.28
5.7
16.4
26.2
1.10
7.6
19.6
43.8
2.32
5.8
16.6
26.0
1.08
7.3
19.4
43.2
2.26
5.5
16.6
26.4
1.14
3-rd stem node stage Puma super Grasp Topik Hussar max LSD 5% LSD 1% LSD 0.1%
7.2
19.2
41.6
2.12
5.6
16.0
27.8
1.20
6.8
18.8
40.8
1.98
5.2
15.6
28.6
1.22
7.0
19.2
41.2
2.04
5.4
15.8
28.6
1.24
6.9
18.8
41.0
2.00
5.6
15.8
28.4
1.22
1.7 3.4 5.3
1.9 3.8 5.0
6.3 7.4 8.6
0.30 0.49 0.66
1.3 2.7 4.0
2.1 3.2 4.3
4.9 6.2 7.7
0.36 0.48 0.60
64
The grain yield does not change, because the decreasing of the last two indexes at main tiller was compensate on their increase at the second tiller and from the higher 1000 grain weight as well. The late treatment with antigraminaceous herbicides in stem elongation stage at a cultivar Vuzhod, in comparison with a cultivar Progress, brings until more weak disturbances of the development (Table 24). The changes to the grain number per spike of the main tiller are not proved, even though the tendency is in evidence such. The 1000 grain in spike of the main tiller decreases mathematically proved by treatment with Puma super, Grasp, Topik and Hussar max in the 3-rd stem node stage only. At the second tiller is in evidence mathematically proved increase on the grain number per spike and the 1000 grain weight only in treatment during 3-rd stem node stage - the plant compensates and the grain yield does not change.
2.5. Grain quality The physical properties of the grain - a mass of 1000 grains, specific weight and vitreousness, do not change under the influence of Puma super, Grapp, Topik and Hussar max on both varieties (Tables 25 and 26). In cultivar Progress, there is a slight unproven, tendency to increase the mass per 1000 grains when using the four herbicides. It is due to the smaller grains number, mainly in spike of the main tiller. The plant compensates and the grain yield does not change. In cultivar Vuzhod, there is a tendency for a 1000 grain weight reduction when treated with antigraminaceous herbicides during stem elongation stage. In cultivar Vuzhod, grain number spike of main tiller does not decrease, as in cultivar Progress.
65
Table 25 Physical and biochemical properties of the cultivar “Progress” (mean 2004 - 2006) Variant
1000 grain weight, g
Test weight, kg
Control
56.2
76.7
Vitreousness %
Protein %
Wet, %
Dry, %
Gluten stretching, cm
87.2
18.66
31.6
12.0
15
Gluten
1-st stem node stage Puma super
56.8
76.3
86.4
18.54
31.5
11.7
15
Grasp
56.4
76.2
87.4
18.27
31.6
11.7
15
Topik
56.6
77.3
85.8
18.27
31.6
11.8
15
Hussar max
56.8
77.1
85.8
18.60
31.6
11.8
15
2-nd stem node stage Puma super
57.4
76.1
85.6
18.27
31.3
11.6
15
Grasp
56.8
76.4
88.2
18.18
31.0
11.4
15
Topik
56.8
77.2
85.4
18.17
31.1
11.5
15
Hussar max
57.2
77.0
85.4
18.44
31.0
11.5
15
30.2
11.4
15
3-rd stem node stage Puma super
57.6
76.9
85.2
17.98
Grasp
57.0
76.3
89.4
18.08
30.0
11.3
15
Topik
57.0
76.9
89.6
17.82
30.2
11.3
15
Hussar max
57.6
76.1
85.8
18.06
30.0
11.2
15
LSD 5% LSD 1% LSD 0.1%
1.8 2.7 3.2
3.5 4.0 5.4
3.2 5.3 7.4
0.60 0.77 0.94
2.3 3.1 4.2
1.0 2.1 3.3
0 0 0
The treatment with the four tested herbicides does not affect the biochemical properties of cultivar Progress. In cultivar Vuzhod, the protein content decreases in all variants, most clearly expressed in the use of herbicides Topic and Hussar max during 3-rd stem node stage, but always kept above the requirements of the standard. Use of herbicides Grasp, Topik and Hussar max during 3-rd stem node stage decreases proven wet and dry gluten content. Decreases in the gluten quantity exist in all variants of this cultivar, but it is always above
66
Table 26 Physical and biochemical properties of the cultivar “Vuzhod” (mean 2004 2006) Variant
1000 grain weight, g
Test weight, kg
Control
54.4
75.6
Vitreousness %
Protein %
Wet, %
Dry, %
Gluten stretching, cm
89.8
18.08
30.6
10.7
15
Gluten
1-st stem node stage Puma super
54.6
76.3
88.2
17.73
29.6
10.4
15
Grasp
54.2
76.2
87.2
17.54
29.6
10.5
15
Topik
54.2
75.8
86.6
18.05
30.0
10.5
15
Hussar max
54.4
75.9
90.2
17.82
29.2
11.0
15
2-nd stem node stage Puma super
53.2
75.8
87.4
17.69
29.4
10.2
15
Grasp
53.4
76.1
88.4
17.43
29.2
10.2
15
Topik
53.6
75.7
89.6
17.36
29.8
10.9
15
Hussar max
53.0
75.9
87.8
17.82
29.0
10.1
15
29.2
10.0
20
3-rd stem node stage Puma super
53.0
76.0
87.6
17.09
Grasp
53.4
75.8
87.2
17.09
26.0
9.8
20
Topik
53.2
75.8
89.2
16.09
26.0
9.4
20
Hussar max
53.0
75.9
87.2
16.27
26.4
9.2
20
LSD 5% LSD 1% LSD 0.1%
2.1 4.0 5.4
3.1 4.9 6.2
3.8 5.2 7.5
0.87 0.99 1.11
2.6 4.0 6.3
0.8 1.9 3.2
4.0 5.5 6.7
the standard requirements of more than 28 % wet gluten and over 10 % dry gluten. The gluten stretchiness increases proven by treatment with all four herbicides during 3-rd stem node stage.
2.6. Sowing properties of the seeds The germinating energy is one of the most important characteristics of the seed sowing properties. Low germinating energy is associated with
67
later germination under field conditions, less hardening of plants, and hence a greater risk of frosting in the winter. The obtained results show that for both cultivars treatment with graminaceous herbicides during 1-st stem node stage of durum wheat does not cause reduction of germination energy. For cultivar Progress, the use of Grasp and Hussar max during the 2-nd stem node stage resulted in a proven decrease in germinative seed energy values (Table 27). In cultivar Vuzhod during this stage and the four herbicides decrease the values of this indicator (Table 28). During 3-rd stem node stage, herbicides Puma super, Grasp, Topic and Hussar max, lead to a mathematically proven reduction in germination in both durum wheat cultivars. Germination is the most important indicator characterizing seed seed properties. For cultivar Progress, none of the tested variants have a suppressive effect on laboratory seed germination. Under their influence the seeds germinate normally, although in some of them, their growth rate is initially weaker due to the weaker germinative energy. In cultivar Vuzhod, the four herbicides applied during 3-rd stem node stage of durum wheat have a strongly depressing effect on laboratory germination values. These variants are also characterized by the strongest negative effect on germinative energy. To compensate for these disadvantages, sowing must be done at a higher sowing rate, which makes production more expensive. Therefore, they should not be applied to seed crops. Treating of cultivar Vuzhod during 2-nd stem node stage with Puma super, Grasp, Topic, and Hussar max also has some suppressing effect on laboratory seed germination, but it always remains above the standard for over 85% germination.
68
Table 27 Influence of the herbicides and their treatment period on cultivar Progress (mean 2004 - 2006) Variant
Germinative power, %
Control
87.0
Germination, % 96.5
Root
Length, cm Coleoptile
Waste grain, %
15.88
13.06
8.4
-st
1 stem node stage Puma super
86.0
96.5
15.87
13.04
8.3
Grasp
81.5
96.5
15.76
12.82
8.4
Topik
85.0
96.0
15.84
13.04
8.7
Hussar max
82.0
95.5
15.29
12.43
8.5
2-nd stem node stage Puma super
83.0
96.0
15.74
12.78
8.7
Grasp
79.0
95.0
15.55
12.62
8.6
Topik
81.5
95.5
15.82
13.03
8.8
Hussar max
78.5
95.0
15.04
12.32
8.7
15.28
12.40
8.9
3-rd stem node stage Puma super
74.0
94.0
Grasp
77.5
95.0
15.26
12.41
10.0
Topik
79.0
95.0
15.80
13.01
9.0
Hussar max
77.5
94.5
14.35
11.64
9.2
6.4 9.3 11.1
5.9 7.5 8.3
0.43 0.61 0.78
0.50 0.66 0.82
1.9 3.3 4.6
LSD 5% LSD 1% LSD 0.1%
The obtained results for germinative energy and seed germination are a prerequisite for the studies to continue and to investigate whether the herbicides do not have a negative effect on the initial growth intensity of the seeds expressed by the length of coleoptile and roots. Herbicide Hussar max was found to be regardless of the stage during which it was introduced, but the length of the primary roots and coleoptile in cultivar Progress always decreased. In this cultivar, a mathematically proven negative influence is also observed in the use of herbicides Puma super and Grasp, but only in the treatment of them during 3-rd stem node stage of 69
Table 28 Influence of the herbicides and their treatment period on cultivar Vuzhod (mean 2004-2006) Variant
Germinative power, %
Control
88.0
Germination, % 95.5
Root
Length, cm Coleoptile
Waste grain, %
15.85
13.29
8.9
-st
1 stem node stage Puma super
84.5
95.0
15.83
13.27
9.0
Grasp
82.0
94.0
15.73
13.19
8.8
Topik
80.5
93.0
15.77
13.24
10.0
Hussar max
81.0
95.0
15.67
13.14
8.9
2-nd stem node stage Puma super
78.0
90.5
15.68
13.13
10.0
Grasp
77.0
92.0
15.70
13.15
8.9
Topik
76.5
90.0
15.72
13.20
10.8
Hussar max
75.0
91.5
15.61
13.03
9.1
15.60
12.98
10.6
3-rd stem node stage Puma super
72.5
88.5
Grasp
71.5
89.0
15.11
12.31
9.0
Topik
70.5
88.0
15.19
12.48
11.1
Hussar max
70.0
87.5
15.23
12.57
9.2
7.8 106 12.8
6.3 8.8 10.4
0.54 0.70 0.91
0.38 0.54 0.78
2.0 3.6 5.2
LSD 5% LSD 1% LSD 0.1%
durum wheat. In the Rise variety, the picture differs significantly from that of Progress. None of the herbicides applied during 1-st and 2-nd stem node stage of durum wheat affects the intensity of the initial growth of the resulting seeds. Three of the tested herbicides, Grasp, Topik and Hussar max applied during 3-rd stem node stage, have been shown to reduce the length of the coleoptiles and the roots in cultivar Vuzhod. The obtained results for germinative energy and seed germination are a prerequisite for the studies to continue and to investigate whether the herbicides do not have a negative effect on the initial growth intensity of 70
the seeds expressed by the length of coleoptile and roots. Herbicide Hussar max was found to be regardless of the stage during which it was introduced, but the length of the primary roots and coleoptile in cultivar Progress always decreased. In this cultivar, a mathematically proven negative influence is also observed in the use of herbicides Puma super and Grasp, but only in the treatment of them during 3-rd stem node stage of durum wheat. In the Rise variety, the picture differs significantly from that of Progress. None of the herbicides applied during 1-st and 2-nd stem node stage of durum wheat affects the intensity of the initial growth of the resulting seeds. Three of the tested herbicides, Grasp, Topik and Hussar max applied during 3-rd stem node stage, have been shown to reduce the length of the coleoptiles and the roots in cultivar Vuzhod. When assessing the sowing properties, account must be taken not only of the characteristics of the seed for sowing, but also of the quantity of waste grain obtained by the preparation of those seeds. For cultivar Progress, none of the tested herbicides affects the amount of the resulting cuttings. For cultivar Vuzhod, a mathematically proven increase in the quantity of waste grain is recorded only when applied with herbicide Topic during 3-rd stem node stage of durum wheat. The higher the amount of seeding results in a higher cost of the resulting seed, therefore this option is not recommended for use in seed crops of cultivar Vuzhod. Other herbicides do not significantly alter the amount of waste grain. The decrease in seed germination and seed germination, the decrease in the initial growth intensity expressed by the root length and coleoptile during germination and the increase in the amount of waste grain under the influence of the respective herbicides are explained by their oppressive impact on the growth and development of durum wheat during its vegetation period. It should be noted, however, that none of the used 71
herbicides: Puma super, Grasp, Topik and Hussar max, irrespective of the period of their treatment, does not result in a proven reduction in grain yield. In some of the variants, some reduction was found, especially in cultivar Progress, but it was not mathematically proved in the dispersion analysis.
72
3. EFFICACY AND SELECTIVITY OF SOME HERBICIDE TANK MIXTURES AND COMBINED HERBICIDES AT LATE TREATMENT OF DURUM WHEAT 3.1. Efficacy against weeds The late optimal sowing time of durum wheat greatly limited opportunities to fight against weeds in the autumn – during after sowing, before germination period and also makes this fight almost impossible during the 3-rd leaf stage of durum wheat. This stage usually begins late in the autumn or the beginning of winter and in most years is accompanied by low temperatures and high soil and atmospheric humidity. These specific characteristics of durum wheat required the fight against weeds is carried out mainly in spring during tillering stage of durum wheat. Often under the influence of various factors - meteorological, organizational, financial et al. - the fight against weeds overdue and durum wheat is entering in stem elongation stage. The question of herbicides selectivity with regard to the plants during stem elongation stage of durum wheat still not well investigated. In some years under the influence of weather conditions, shoots of perennial weeds appear later in the spring and to the formation of their optimal size for herbicide action durum wheat is entering in stem elongation stage. This requires the fight against perennial weeds sometimes be done during the early periods of this stage. In order to determine the impact of a group of herbicides and herbicide combinations applied during the beginning of stem elongation stage, a field experiment with durum wheat cultivar Zvezditsa was carried out to control annual graminaceous, annual and perennial broadleaved weeds. 6 new products have been tested: 1 combined herbicide - Axial one; 2 antigraminaceous herbicides - Axial and Traxos; 3 antibroadleaved 73
herbicides - Lintur, Logran and Bromotril. 4 tank mixtures between antigraminaceous and antibroadleaved herbicides also have been tested: Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur. The active substances and dosages of studied herbicides and herbicide mixtures during tillering and stem elongation stages are described in detail in Table 3 of the Material and Methods section. In addition to tillering stage, the preparations are also applied during stem elongation stage to investigate the possibilities for control of secondary weed infestation in durum wheat commodity and seed crops. Annual broadleaved weeds in the experience are represented by Anthemis arvensis L., Chamomilla recutita Rauchert, Galium aparine L., Sinapis arvensis L., Raphanus raphanistrum L., Capsella bursa-pastoris L., Falopia convolvulus Leve, Lithospermum arvense L., Papaver rhoes L., Consolida regalis Gray, Viola tricolor L., Myagrum perfoliatum L., Lamium purpureum L., Veronica hederifolia L., Stellaria media Cyr. Perennial broadleaf weeds are established Cirsium arvense Scop., Convolvulus arvensis L., Cardaria draba L., Sonchus arvensis L. Graminaceous weeds are reported Avena fatua L., Avena ludoviciana Durien., Alopecurus myosuroides L., Apera spica-venti P.B., Lolium temulentum L., Lolium multiflorum L., Bromus arvensis L. Combined herbicide Axial one and tank mixtures between antigraminaceous herbicides Axial and Traxos on one side, and antibroadleaved herbicides Lintur, Logran and Bromotril on the other, have very good efficacy against Avena fatua L., Avena ludoviciana Durien., Alopecurus myosuroides L., Apera spica-venti P.B., Lolium temulentum L., Lolium multiflorum L., when they are treated in tillering stage of the durum wheat (Table 29). Herbicides Axial one and Axial are not efficacy against Bromus arvensis L. only. They destroy about 10% of the plants, mainly 74
those that are in very early stages of their development. The combination of active substances of antigraminaceous herbicides Axial and Topic (respectively pinoxaden and clodinafop) in herbicide Traxos result in synergism and good herbicidal efficacy against Bromus arvensis L. – 92 % at treatment during tillering stage.
Avena ludoviciana
Lolium multiflorum
Lolium temulentum
Alopecurus myosoroides
Apera spica-venti
Bromus arvensis
Cirsium arvense
Convolvulus arvensis
Control – untreated
Avena fatua
Variants
Weeds
Table 29 Efficacy of some herbicide mixtures against annual graminaceous and perennial broadleaved weeds according to the 100 % visual scale of EWRS (mean 2009 - 2011)
0
0
0
0
0
0
0
0
0
Tillering stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
100
100
100
100
100
100
10
100
10
100
100
100
100
100
100
10
100
82
100
100
100
100
100
100
10
94
0
100
100
100
100
100
100
10
100
0
100
100
100
100
100
100
92
100
82
Stem elongation stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
100
94
88
87
92
90
0
96
88
100
94
88
87
92
90
0
96
92
100
94
88
87
92
90
0
82
0
100
94
88
87
92
90
0
96
0
100
98
95
95
98
94
80
96
92
75
The antibroadleaved herbicides Lintur, Logran and Bromotril applied during tillering stage show very good efficacy against the perennial broadleaved weeds Cirsium arvense Scop. and Cardaria draba L. – 100 % for Lintur and Bromotril and 94 % for Logran. Herbicide Lintur is less efficacious against Convolvulus arvensis L. - it controls at 82 %. Herbicides Logran and Bromotril are inefficacy against Convolvulus arvensis L. Combined herbicide Axial one has very high efficacy against Cirsium arvense Scop. and Cardaria draba L. It has low efficacy against Convolvulus arvensis L. - it controls at 10 %. The differences in efficacy are due to the late emergence of this weed. Lintur, besides foliar action, has also soil action, as a result of which satisfactory control of Convolvulus arvensis L. is carried out. Axial one, Logran and Bromotril are typical foliar herbicides, and applied during tillering stage cannot control shoots emerging after the treatment time of this late-spring perennial weed. Antibroadleaved herbicides Lintur, Logran and Bromotril, applied during tillering stage, have very good efficacy against almost all annual broadleaved weeds (Table 30). Lintur and Logran are fewer efficacies against Consolida regalis Gray - they control it at 45 % and 40 %, respectively. Bromotril has a very high efficacy against this weed. The combined herbicide Axil one has a very good efficacy against all annual broadleaved weeds, including Consolida regalis Gray. During stem node stage treatment, a reduction in the efficacy of all herbicides and herbicide tank mixtures are obtained for some winter-spring weed as Avena ludoviciana Durien., Alopecurus myosuroides L., Apera spica-venti P.B., Lolium temulentum L., Lolium multiflorum L., Anthemis arvensis L., Chamomilla recutita Rauchert, Capsella bursa-pastoris L., 76
Raphanus raphanistrum
Anthemis arvensis
0
0
0
0
Selectivity
Consolida regalis
0
Falopia convolvulus
Papaver rhoes
0
Myagrum perfoliatum
Chamomolla recondita
Control – untreated
Galiun aparine
Variants
Weeds
Table 30 Efficacy of some herbicide mixtures against annual broadleaved weeds according to the 100 % visual scale of EWRS and selectivity according to the 9-rate scale of EWRS (mean 2009 - 2011)
0
0
1
Tillering stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
100
100
100
100
95
100
100
100
1
100
100
100
45
95
100
100
100
1
100
100
100
40
100
100
95
100
1
100
100
100
100
100
100
95
100
1
100
100
100
45
95
100
100
100
1
Stem elongation stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
100
98
94
95
92
98
100
100
2
100
96
95
35
90
96
100
100
2
100
95
92
30
88
94
92
95
2
100
97
93
92
85
98
90
97
2
100
96
95
35
90
96
100
100
3
Papaver rhoes L., Viola tricolor L. This decrease is mainly observed for those weeds that have advanced in development and have passed the optimal for treatment stage. It should be borne in mind that the abovementioned graminaceous and broadleaved weeds form the primary, but not the secondary weed infestation of durum wheat crops. In the early spring weeds of Avena fatua L., Galium aparine L., Sinapis arvensis L., Raphanus raphanistrum L., Myagrum perfoliatum L., 77
Falopia convolvulus Leve, Lithospermum arvense L., Consolida regalis Gray, efficacy persists because at the treatment time at the beginning of stem elongation stage they are still in earlier stages of their development. Applying of combined herbicide Axial one and herbicide mixtures Axial + Lintur, Axial + Bromotril and Traxos + Lintur during stem elongation stage resulted in a slight decrease by 4 % of their efficacy against Cirsium arvense Scop. More significantly, with 12 % is the reduction in herbicidal efficacy against Cirsium arvense Scop. in the herbicide Axial + Logran. The use of herbicide Axial one and tank mixtures Axial + Lintur and Traxos + Lintur during stem elongation stage increases their efficacy only against Convolvulus arvensis L. The increase in efficacy in Axial one is 78 % and is significantly greater than that of the Lintur with 10 %. At Axial one, the efficacy increases from 10 % to 88 % and in Lintur from 82 % to 92 %. The high efficacy of Axial against Convolvulus arvensis L. during stem elongation stage is due to the fact that the treatment time with this foliar-applied herbicide coincides with the period of the massive appearance of the shoots of Convolvulus arvensis L.
3.2. Selectivity to durum wheat Treatment in stem elongation stage with combined herbicide Axial one and tank mixtures Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur produced slight phytotoxicity of durum wheat - rating 2 by the scale of EWRS (Table 30). It is expressed in light chlorosis on the leaves of durum wheat.
78
In the Traxos + Lintur tank, phytotoxic effects are slightly stronger rating 3 by the scale of EWRS. It is overcome after 5-7 days and has no mathematically proven reduction on the grain yield. All herbicides and tank mixtures which treated during the tillering stage have very high selectivity for durum wheat - rating 1 by the scale of EWRS.
3.3. Grain yields. Stability and technological value of yields The obtaining grain yields are the result of the combined effect of the efficacy and selectivity of investigated herbicides and herbicide tank mixtures (Table 31). In treatment during tillering stage highest grain yield obtained by tank mixtures Traxos + Lintur – 4993 kg/ha, or 114.9 % over untreated control. Very similar yield is obtained by treatment with Axial + Bromotril – 4963 kg/ha, or 114.2 %. These yields are the result of good herbicidal efficacy and high selectivity of these herbicide combinations. In the treatment in stem elongation stage with herbicide mixture Axial + Bromotril is obtained the highest grain yield of 4769 kg/ha – 109.8 %. Tank mixture Traxos + Lintur is the second one with 4740 kg/ha, or 109.1 %. Differences in yields between these two variants do not prove mathematically. Slightly lower are the yields of combined herbicide Axial one and tank mixtures Axial + Lintur and Axial + Logran. The reason for this is their lower herbicidal efficacy in treatment during stem elongation stage.
79
Table 31 Influence of some herbicide tank mixtures on grain yield of durum wheat (2009 - 2011) Factor Ⱥ
Factor ȼ
2009
2010
Mean (Factor ȼ)
2011
kg/ha
%
kg/ha
%
kg/ha
%
kg/ha
%
Control - untreated
3460
100
4735
100
4840
100
4345
100
Axial one
3758
108.6
5355
113.1
5368
110.9
4827
111.1
3717
107.4
5313
112.2
5319
109.9
4783
110.1
3740
108.1
5327
112.5
5339
110.3
4802
110.5
3874
112.0
5497
116.1
5518
114.0
4963
114.2
3906
112.9
5526
116.7
5547
114.6
4993
114.9
Tillering stage
Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
Stem elongation stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
3630
104.9
5180
109.4
5188
107.2
4666
107.4
3584
103.6
5114
108.0
5126
105.9
4608
106.1
3587
103.7
5261
111.1
5213
107.7
4687
107.9
3717
107.4
5284
111.6
5305
109.6
4769
109.8
3688
106.6
5261
111.1
5271
108.9
4740
109.1
-
5260
-
5276
-
Mean 3696 (Factor Ⱥ) LSD, kg/ha: F.A p5%=159 F.B p5%=213 AxB p5%=296
p1%=178 p1%=250 p1%=360
-
p0.1%=202 p0.1%=295 p0.1%=438
Analysis of variance for grain yield (Table 32) shows that the years have the highest influence on grain yield – 83.9 % on the variants. The reason is the large differences in the meteorological conditions during the three years of investigation. The strength of influence of herbicides is 6.6 %. The influence of years and herbicides is well proven at p 0.1 %. There is an interaction between herbicides and meteorological conditions of years (AxB) – 1.4 %. It is proven at p 5 %.
80
Table 32 Analyses of variance for grain yield Source of variation
Degrees of freedom
Sum of squares
Influence of factor. %
Mean squares
Total
98
623350
100
-
Tract of land
2
41364
6.6
20682.0***
Variants
32
572750
91.9
17898.4***
2
543208
83.9
271604.0***
10
27822
6.6
2782.2***
20
1720
1.4
186.8*
9236
1.5
144.3
Factor A – Years Factor B – Herbicides AxB Pooled error *p5%
64 **p1%
***p0.1%
Based on proven herbicide x year interaction, it was evaluated stability parameters for each herbicide for grain yield of durum wheat with relation to years (Table 33). It was calculated the stability variances ıi2 and Si2 of Shukla, the ecovalence Wi of Wricke and the stability criterion YSi of Kang. Stability variances (ıi2 and Si2) of Shukla, which recorded respectively linear and nonlinear interactions, unidirectional evaluate the stability of the variants. These variants which showed lower values are considered to be more stable because they interact less with the environmental conditions. Negative values of the indicators ıi2 and Si2 are considered 0. At high values of either of the two parameters - ıi2 and Si2, the variant are regarded as unstable. At the ecovalence Wi of Wricke, the higher are the values of the index, the more unstable is the variant. On this basis, using the first three parameters of stability, it is found that the most unstable are untreated control and herbicide tank mixture Axial + Logran during stem elongation stage. In these variants values of
81
Table 33 Stability parameters of some herbicide mixtures for grain yield with relation to years Variants
Control - untreated
_ x
4345
ıi2
Si2
Wi
YSi
789.1**
150.8
1306.8
-10
Tillering stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
4827
3.2
-1.9
20.9
12+
4783
0.8
-0.4
16.9
10+
4802
-3.6
-1.7
9.7
11+
4963
38.0
-1.8
77.8
13+
33.5
-1.8
70.5
14+
4993
Stem elongation stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
4666
-5.3
-1.0
7.0
2
4608
4.8
-1.3
23.6
-1
4687
603.9*
75.3
1185.7
-1
4769
-8.9
-1.7
1.1
9+
4740
-8.7
-1.4
1.5
5
stability variance ıi2 and Si2 of Shukla and ecovalence Wi of Wricke are the highest and mathematically proven. The reason for this high instability is the greater variation in grain yields as a result of the greater number of undisturbed weeds in herbicide tank mixture Axial + Logran. Other herbicides and herbicide tank mixtures exhibit high stability because they interact poorly with the conditions of years. To evaluate the complete efficacy of each tank mixture between antigraminaceous herbicide and antibroadleaved herbicide should be considered as its effect on grain yield of durum wheat and its stability - the reaction of wheat to this variant during the years. Valuable information about the value of technologic value of the variant give the stability 82
criterion YSi of Kang for simultaneous assessment of yield and stability, based on the reliability of the differences in yield and variance of interaction with the environment. The value of this criterion is experienced that using nonparametric methods and warranted statistical differences we get a summary assessment aligning variants in descending order according to their economic value. Generalized stability criterion YSi of Kang, taking into accounts both the stability and value of yields gives a negative assessment of untreated control and herbicide tank mixtures Axial + Logran and Axial + Lintur, characterizing them as the most unstable and low yields. Kang's criterion YSi characterized the control as stable, but the lowest yield, while herbicides Cougar and Eagle as unstable and low-yielding. This is the result of the smaller possibilities of these two mixtures to control secondary weed infestation with some graminaceous and broadleaved species during late treatment. According to this criterion, technologically the most valuable appears applied during tillering stage herbicide tank mixtures Traxos + Lintur, Axial + Bromotril, Axial + Logran, Axial + Lintur and also combined herbicide Axial one. To this group also falls the herbicide mixture Axial + Bromotril applied during stem elongation stage. These variants combine high levels of grain yield and high stability of this index during the years. From the viewpoint of technology for durum wheat growing, high ratings also have herbicide tank mixture Traxos + Lintur and combined herbicide Axial one applied during stem elongation stage. They combine relatively good grain yields with high stability during the years of the investigation.
83
3.4. Structural elements of yield. Plant height In order to explain changes in grain yield, some of the structural elements in main in second tillers that determine it are examined (Table 34 and 35). Differences in the efficacy and selectivity of tested herbicides and herbicide tank mixtures result in changes in the values of the spike length, number of spikelets per spike, number of grains per spike, and grain weight per spike of the main and the second tillers. These differences are mathematically proven in the analysis of variance.
Table 34 Influence of some herbicide tank mixtures on structural elements of the yield in main tiller (mean 2009 - 2011) Variants
Control - untreated
Spike length of main tiller, cm
Spikelets per spike of main tiller, number
Grains per spike of main tiller, number
Grain weight per spike of main tiller, g
Height of main tiller, cm
7.2
18.8
35.8
2.04
87.0
Tillering stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
8.1
21.6
46.2
2.64
91.2
8.0
21.0
44.0
2.42
91.8
8.0
20.8
44.2
2.48
91.4
8.1
21.2
44.0
2.66
91.6
8.1
21.8
49.0
2.78
89.5
Stem elongation stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur LSD 5% LSD 1% LSD 0.1%
7.8
19.6
36.4
2.12
91.0
7.8
19.4
36.8
2.10
91.5
7.8
20.4
38.2
2.16
91.2
7.9
21.0
39.0
2.28
91.5
7.9
20.8
38.4
2.22
89.3
0.8 1.6 2.7
1.1 2.0 3.2
2.9 4.4 6.1
0.20 0.31 0.44
3.3 5.3 7.5
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Table 35 Influence of some herbicide tank mixtures on structural elements of the yield in second tiller (mean 2009 - 2011) Variants
Control - untreated
Spike length of second tiller, cm
Spikelets per spike of second tiller, number
Grains per spike of second tiller, number
Grain weight per spike of second tiller, g
Height of second tiller, cm
6.0
16.8
20.6
0.55
74.0
Tillering stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
6.2
17.2
22.8
0.83
78.3
6.2
17.0
22.0
0.73
78.8
6.1
17.4
22.2
0.82
78.4
6.2
17.2
22.6
0.94
78.5
6.2
17.0
21.6
0.86
78.1
Stem elongation stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur LSD 5% LSD 1% LSD 0.1%
6.4
17.8
26.2
1.20
81.1
6.3
16.8
24.4
1.06
81.4
6.4
17.0
24.6
1.10
81.2
6.4
17.4
28.6
1.30
81.3
6.4
17.2
27.2
1.34
80.9
0.6 1.3 2.4
0.9 1.7 2.9
3.0 4.6 6.3
0.18 0.27 0.39
2.7 4.8 6.9
Treatment with investigated herbicides and their tank mixtures in tillering stage has a positive influence on the structural elements of the spike of the main and the second tillers. The main reason for this is the removal of the negative influence of weeds. Meanwhile, compared to untreated control, the increase in the herbicide mixtures Traxos + Lintur, Axial + Bromotril and the combined herbicide Axial one during tillering stage treatment is greatest. For the second tiller spikes, the increase in these values vs. untreated control is less, but it is also mathematically proved in the dispersion analysis.
85
Compared with the tillering stage, late treatment with investigated herbicides mixtures in stem elongation stage leads to weak disturbances in development. Their use leads to mathematically proven reduction in spike length, spikelet’s number per spike, grain number per spike and grain weight per spike in the main tiller. At the same time their treatment during this stage leads to increasing in their values in the spike of the second tiller. The increase is greatest and mathematically proven in the grain number per spike and grain weight per spike. Finally, grain yield in these variants is changed very slightly, because the decrease in the values of the last two parameters in the main tiller is compensated by the increase in their second tiller. An increase in the spike length was found. The increase of this indicator is less, but it is also mathematically proven. The spike length has a lesser influence on the yield value. The spike may be very long but loose, with a smaller spikelets number on spike spindles. More important for durum wheat is that all spikes is well-rounded, well-fed and ripe, without sterile grains at the base and top of the spike. The herbicides also influence the heights of main and second tillers. It is the lowest in untreated control. This is due to the competition between weeds and wheat plants available in control. The elimination of the negative effect of the weeds leads to an increase of the heights of main and second tillers in all variants. Of the treated variants, the height of the main tiller is the lowest for herbicide tank mixture Traxos + Lintur and during the two treatment stages. Since this reduction is not accompanied by a decrease in grain yield, this herbicide tank mixture has a retardant but not phytotoxic effect. Compared to tillering stage, the late treatment with herbicide Axial one and herbicide tank mixtures Traxos + Lintur, Axial + Bromotril, Axial 86
+ Logran and Axial + Lintur during stem elongation stage resulted in an increase in the height of second brother relative to the values of the respective variants during tillering stage. Apparent early treatment during tillering stage with tested herbicides and herbicide tank mixtures has a retardant effect on second tiller of durum wheat plant, but late treatment in stem elongation stage does not affect its height. In general, the increase in the height of main and second plant tillers is due both to the high herbicide efficacy and to the high selectivity of the herbicides and herbicide mixtures for durum wheat.
3.5. Grain quality indicators For milling industry critical so-called mills qualities of wheat. They are higher in uniform grain, color, shape and virtuousness grains. In such batches, durum wheat is most successfully applied by the digestion schemes to achieve a certain yield and the quality of the semolina. The 1000 grain weight affects the semolina yield, equally in the grain shape and the endosperm structure. It varies depending on the conditions of cultivation. The 1000 grain weight is increased by treatment with combined herbicide Axial one and tank mixtures Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur (Table 36). Changes between variants which treated in tillering and stem elongation stages are not been proven. In all variants the values of this index are above the requirements of international standards. Test weight is one of the most important technological parameters. Usually an increase in the nitrogen rate lead to test weight decreases. This is associated with receipt of a loose cellular tissue at higher nitrogen
87
Table 36 Influence of some herbicide tank mixtures on physical and biochemical properties the grain (mean 2009 - 2011) Variants Control - untreated
Gluten, %
1000 grain weight, g
Test weight, kg
Vitreousness, %
Protein, %
Wet
Dry
50.8
80.6
78.4
11.92
23.5
8.4
Tillering stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
52.4
81.6
86.0
13.75
28.5
10.5
52.4
81.2
85.2
13.65
28.0
10.3
53.0
81.0
84.4
13.49
27.9
9.9
51.4
81.0
87.8
13.59
28.0
10.1
51.8
81.5
88.2
13.80
27.8
9.9
Stem elongation stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur LSD 5% LSD 1% LSD 0.1%
52.2
80.6
84.4
13.83
29.2
10.6
52.0
80.0
83.6
13.80
29.0
10.6
52.2
80.6
83.6
13.53
28.7
10.1
51.2
80.1
83.8
13.69
28.8
10.3
51.4
80.5
86.2
13.90
28.8
10.0
2.1 4.0 4.9
3.0 3.9 5.1
5.1 6.3 8.0
1.01 1.16 1.33
3.1 5.5 7.8
1.0 3.1 4.4
fertilization, especially in dry conditions. Of grain with a high test weight is obtained a higher semolina yield and a lesser bran amount. Treatment with the investigated herbicides and tank mixtures between them does not adversely affect the test weight of the grain. Test weight retains its high values typical of durum wheat - at all variants it is over 80 kg. The consistency of the grain is paramount for the evaluation of durum wheat and characterizes not only mills but also its macaroni properties. Durum wheat with a high percentage of vitreousness grains has a higher protein and gluten content, and the pasta obtained from it has a pleasant creamy yellow to amber color. Higher vitreousness grains when
88
grinded are broken down more quickly and lightly into semolina and dunst, easier to sift and separate from the grain coat and give a higher semolina yield. Vitreousness of the grain increases by influence of the investigated herbicides, as a result the removal of the negative influence of the weeds. In all variants virtuousness is high - over 79 % and a value above the requirements of international standards for over 75% vitreousness. The keeping the physics properties of the grain (1000 grain weight, test weight and vitreousness) high and stable guaranteed good mill qualities and high semolina output. Other indexes included in the investigation characterized the biochemical properties of the grain from the different variants as raw material for the pasta production. The protein quantity and the wet and dry gluten quantities are one of the most important indexes, leading to pasta with a good culinary quality. The protein quantity is definitely by cultivar, but it varies depending on weather conditions and the agrotechnology. The protein content is increased by treatment with the combined herbicide Axial one and the herbicide tank mixtures Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur. There are no differences between the respective variants when inserted during tillering and stem elongation stages. The quantities of wet and dry gluten are an important element of the grain quality characteristic. The use of herbicide combinations Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur and combined herbicide Axial one during the tillering and stem elongation stages of durum wheat increases the wet and dry gluten contents. The ratio between wet and dry gluten (2.5 - 3 to 1) remains unchanged and favorable for the production of high quality pasta products.
89
In the evaluation of the physical and biochemical properties of the grain should be borne in mind that their increase not due to the direct stimulatory effects of used herbicides. The increase compared to the untreated control is indirectly and is due to good herbicide efficacy against weeds and good selectivity of herbicides to durum wheat in its growing period. Used herbicides liquidated negative influence of weeds enable durum wheat to realize its high quality and productive potential, based on the genetic traits of the using cultivar Zvezditsa and other units of the cultivation technology, especially of soil fertilization with mineral fertilizers.
3.6. Sowing characteristics of seeds The realization of the biological potential of durum wheat is closely related to the creation of well-garnished and high-yielding crops for which high-quality seeds are needed. Herbicides are a systematically acting stress factor in the environment and, in addition to direct action; they also have a specific effect on next generation plants. Sometimes, in practice, under the influence of various factors (meteorological, financial, organizational), the herbicide campaign is delayed and the crops must be treated during beginning of stem elongation stage. Since part of the grain is used as seed for sowing, it is necessary to study the question of the impact of herbicides and herbicide mixtures used in seed crops during this stage on the quality of durum wheat sowing-seed. One of the important conditions for obtaining a normal crop and a good harvest is the use of quality seeds. Apart from the high-yield cultivar which is resistance to diseases and pests, it must have the necessary sowing properties, the main of which are high germination energy and seed 90
germination. Germination energy is one of the most important characteristics of the sowing properties of the seed. The low germination energy is the reason for slower development of primary roots and coleoptile after seed germination and is associated with later germination in field conditions, less tempering of plants and a higher risk of frost in the winter. Its lead to lower grain yields. Germination is the most important index who characterizing the sowing properties of the seed. At low laboratory germination sowing should be done with higher sowing rate, which increases the cost production. The obtained results show that the treatment of the durum wheat with combined herbicide Axial one and herbicide tank mixtures Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur during tillering and stem elongation stages does not lead to proven changes in the germination energy and seed germination (Table 37). The obtained results for germination energy and seed germination are a prerequisite continue to investigate the effect of herbicides and their tank mixtures on initial intensity of the growth of seeds, expressed by the length of roots and coleoptiles. It was found that all investigated herbicide mixtures when they treated in tillering and stem elongation stages have positive effect in the length of primary roots and coleoptiles of durum wheat. This means that combined herbicide Axial one and tank mixtures Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur stimulate development of young plants, increase their resistance to cold and decrease risk of frost during winter months, compared with the untreated, weed infested control. At the evaluation of the sowing characteristics we have to consider not only the characteristics of the sowing seeds but also the quantity of the waste grain (siftings) which are gained at the preparation of these seeds.
91
Table 37 Influence of some herbicide tank mixtures on sowing characteristics of the seeds (mean 2009 - 2011) Variants
Length, cm
Germinative energy, %
Germination, %
Coleoptile
Root
Waste grain, %
73.5
95.5
10.66
17.06
19.8
Control - untreated
Tillering stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur
90.5
96.0
12.10
18.85
14.4
92.5
96.5
11.86
17.80
14.4
93.0
97.0
11.72
17.84
13.9
89.5
96.5
11.83
19.11
14.2
95.0
96.5
12.16
18.55
14.1
Stem elongation stage Axial one Axial + Lintur Axial + Logran Axial + Bromotril Traxos + Lintur LSD 5% LSD 1% LSD 0.1%
91.0
96.0
11.89
18.81
11.9
93.0
97.0
11.51
17.85
12.1
92.5
96.5
11.97
17.84
11.3
92.0
97.0
11.69
17.92
11.7
96.0
97.0
11.74
18.11
11.1
4.9 6.1 7.7
4.7 5.9 7.4
0.74 1.02 1.38
1.01 1.32 1.73
1.3 2.6 3.8
Treatment with combined herbicide Axial one and herbicide tank mixtures Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur leads to a reduction in the quantity of waste grain. The reduction of siftings in treatment in stem elongation stage is greater than the reduction in treatment in tillering stage. This is probably due to larger grains derived from the spikes of the second tiller. A small quantity of waste grain leads to lower cost of the seed and increases the economic impact of seed production of durum wheat. Changes in the values of germination energy, laboratory seed germination, and the intensity of the initial growth, expressed by the length
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of the root and coleoptile at germination and as such as the decrease in the quantity of waste grain under the influence of the herbicides are explained by the good herbicide efficacy on weeds and good selectivity to the durum wheat during its vegetative period.
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4. CHANGES IN PRODUCTIVITY OF DURUM WHEAT BY TREATMENT DURING VEGETATION PERIOD WITH HERBICIDE GLYPHOSAN 4.1. Efficacy against weeds and self-sown plants In rare crops of durum wheat or in the case of mistakes in the choice of suitable herbicides, secondary weed infestation is often obtained. In seed crops of durum wheat, secondary weed infestation is also often obtained because they are often sown at a lower sowing rate in order to obtain a higher breeding coefficient. Secondary weeds and self-sown plants from the predecessor make it difficult to harvest and increase the moisture grain. This necessitates a drying of the grain after harvesting. This requires these weeds and self-sown plants to be treated with a total herbicide before harvesting. Annual graminaceous weeds in the experience are represented by Avena fatua L., Lolium temulentum L., Lolium multiflorum L. and Bromus arvensis L. Perennial graminaceous weeds are reported Sorgum helepense Pers., Cynodon dactylon Pers., Agropirum repens L. and Scirpus mucronatus L. Perennial broadleaved weeds are established Cirsium arvense Scop., Convolvulus arvensis L., Cardaria draba L. and Sonchus arvensis L. Annual broadleaved weeds in the experience are not established. Self-sown plants are from Clearfield canola (Brassica napus L.), Clearfield and ExppessSun sunflower (Helianthus annuus L.), coriander (Coriandrum sativum L.) and milk thistle (Silybum marianum Gaertn.). They are sown manually when sowing durum wheat. These secondary emerged weeds and self-sown plants are developed after treatment with antibroadleaved herbicide Granstar 75 DF (tribenuron-
94
methyl) at dose of 20 g/ha and antigaminaceous herbicide Scopio super 100 EC (phenoxyprop-ethyl) at dose of 700 ml/ha. These two herbicides were applied during tillering stage of durum wheat as tank mixture. The foliar total herbicide Glyphosan 36 SL (glyphosate) applied at dose of 12 l/ha during milk development (Zadoks’ scale 77), dough development (Zadoks’ scale 85) and ripening (Zadoks’ scale 92) stages of the durum wheat, has a 100 % efficacy against the high-stem perennial broadleaved weeds Cirsium arvense Scop. and Sonchus arvensis L. (Table 38).
Convolvulus arvensis
Cardaria draba
Sonchus arvensis
Brassica napus 1
Helianthus annuus 2
Helianthus annuus 3
Coriandrum sativum 4
Silybum marianum 5
Control
0
0
0
0
0
0
0
0
0
Milk development
100
100
88
100
100
100
100
100
100
Dough development
100
100
95
100
100
100
100
100
100
Ripening
100
100
99
100
100
100
100
100
100
Stages of treatment with Glyphosan
Weeds
Cirsium arvense
Table 38 Efficacy of herbicide Glyphosan against perennial broadleaved weeds and self-sown plants at durum wheat according to the 100 % visual scale of EWRS (mean 2008 - 2010)
1
- self-sown plants of Clearfield canola, - self-sown plants of Clearfield sunflower, 3 - self-sown plants of ExpressSun sunflower, 4 - self-sown plants of coriander, 5 - self-sown plants of milk thistle 2
95
The herbicide also has high efficacy against Convolvulus arvensis L. because its stems are wrapped around the wheat stems and go over them. Against Cardaria draba L. the efficacy is weaker - from 88 % to 99 %. This is due to the lower height of this weed. During milk development stage, the so-called "umbrella effect" is manifested: durum wheat still has green leaves that partially covers the weed’s plants and prevents the herbicide from penetrating in them. With the leaves dying out during dough development and ripening stages, the "umbrella effect" decreases and this leads to an increase in the efficacy of Glyphosan against Cardaria draba L. Herbicide Glyphosan has a very good efficacy against the self-sown plants of Clearfield canola, Clearfield sunflower, ExpressSun sunflower, coriander and milk thistle.
Cynodon dactylon
Agropirum repens
Scirpus mucronatus
Avena fatua
Lolium multiflorum
Lolium temulentum
Bromus arvensis
Selectivity
Control
0
0
0
0
0
0
0
0
1
Milk development
100
87
87
100
100
100
100
100
9
Dough development
100
94
95
100
100
100
100
100
3
Ripening
100
97
98
100
100
100
100
100
1
Stages of treatment with Glyphosan
Weeds
Sorgum helepense
Table 39 Efficacy of herbicide Glyphosan against perennial and annual graminaceous weeds at durum wheat according to the 100 % visual scale of EWRS and selectivity according to the 9-rate scale of EWRS (mean 2008 2010)
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The herbicide has 100 % efficacy against high-stem perennial graminaceous weeds (Table 39) such as Sorgum helepense Pers. and Scirpus mucronatus L. Against low-stem perennial weeds Cynodon dactylon Pers. and Agropirum repens L., the efficacy is weaker and varies from 87 % to 98 %. It is due to the "umbrella effect" and increases with the decay of durum wheat leaves. Herbicide Glyphosan completely destroys the annual graminaceous weeds Avena fatua L., Lolium temulentum L., Lolium multiflorum L. and Bromus arvensis L. Thus, the herbicide prevents scattering before harvesting the ripe and viable seeds of these weeds and prevents the future weed infestation of these areas.
4.2. Selectivity to durum wheat Treating with foliar total herbicide Glyphosan during milk development (Zadoks’ scale 77) stage (at 30 – 40 % grain moisture) completely destroys durum wheat plants - rating 9 by the scale of EWRS (Table 39). The crop does not ripen normally, it dries and is premature, and this leads to a reduction in grain yield. Herbicide treatment during dough development (Zadoks’ scale 85) stage (at 20 – 25 % grain moisture) causes poor phytotoxicity to durum wheat - rating 3 by the scale of EWRS. Herbicide Glyphosan, applied during ripening (Zadoks’ scale 92) stage (at 14 – 15 % grain moisture), exhibits very high selectivity to durum wheat - rating 1 by the scale of EWRS. The reason is a lack of fresh leaves through which the herbicide enters the wheat plants, as a result of which they normally end their vegetation.
97
4.3. Grain yields. Stability and technological value of yields The obtained grain yields are the result, on the one hand, of the cumulative effect of the efficacy and selectivity of the herbicide Glyphosan and on the other, of the influence of the weather conditions on the durum wheat cultivars (Table 40). Treatment with foliar systemic non-selective herbicide Glyphosan during milk development (Zadoks’ scale 77) stage of
Table 40 Influence of herbicide Glyphosan on grain yield of durum wheat (2008 2010) Variants Cultivars
2008
2009
2010
Mean
Control
3375
5825
5230
4810
Milk development
3125
5025
5015
4388
Dough development
3238
5750
5215
4734
Ripening
3338
5888
5275
4833
Control
3305
5875
4585
4588
Milk development
3100
4825
4383
4103
Dough development
3200
5800
4578
4526
Ripening
3300
5900
4595
4598
Stages of treatment with Glyphosan
Victoria
Predel
LSD, kg/ha: F.A p5%=98 F.B p5%=80 F.C p5%=113 AxB p5%=139 AxC p5%=196 BxC p5%=160 AxBxC p5%=277
p1%=131 p1%=106 p1%=150 p1%=184 p1%=260 p1%=212 p1%=368
98
p0.1%=169 p0.1%=138 p0.1%=195 p0.1%=239 p0.1%=338 p0.1%=276 p0.1%=478
durum wheat are reduced significantly the grain yield - with 422 kg/ha, or 8.8 % in cultivar Victoria and 485 kg/ha, or 10.6 % in cultivar Predel, average of period of investigation. The most phytotoxic effect was reported in 2008, where the reduction in grain yield was 13.7 %, or 800 kg/ha in Victoria and 17.9 %, or 1050 kg/ha in Predel. Treatments during dough development (Zadoks’ scale 85) and ripening (Zadoks’ scale 92) stages of the durum wheat when there is no fresh green foliage in which herbicide to penetrate in the plant does not lead to mathematically proven reduction in grain yield. Analysis of variance for grain yield (Table 41) shows that the years have the highest influence on grain yield – 88.3 % on the variants. The reason is the large differences in the meteorological conditions during the three years of investigation. The strength of influence of cultivars is 1.3 % and the strength of influence of herbicide Glyphosan is 3.3 %. The influence of years is very well proven at p 0.1 %. The influence of cultivars and the herbicide is well proven at p 1 %. There is a very well proven interaction between cultivars and meteorological conditions of years (AxB) – 1.9 % and between herbicide Glyphosan and meteorological conditions of years (AxC) – 2.1 %. It is proven at p 0.1 %. Interactions cultivar x year and herbicide x year are significant for grain yield and are determined by the different reaction of the variants to the change in the environmental conditions. There is no proven interaction between cultivars and stages of treatment with Glyphosan (BxC), as well as between the three factors of the experiment (AxBxC). The unproven interaction cultivar x herbicide shows, that treatment with Glyphosan during different stages has a one-way effect on grain yield for both durum wheat cultivar - Victoria and Predel. During milk development stage, this effect is negative, and during dough development and ripening stages it is partially positive. 99
Table 41 Analysis of variance for grain yield Total
Degrees of freedom 95
Sum of squares 1052876
Influence of factor. % 100
Tract of land
3
2070
0.3
690.0
Variants Factor A – Years Factor B – Cultivars Factor ɋ – Stages of treatment AxB
23
1024868
97.2
44529.1***
2
933208
88.3
466604.0***
1
13562
1.3
13562.0**
3
35252
3.3
11750.7***
2
20290
1.9
10145.0***
AxC
6
20944
2.1
3490.7***
BxC
3
204
0.2
68.0
AxBxC
6
708
0.1
118.0
26638
2.5
386.1
Source of variation
Pooled error *p5%
69 **p1%
Mean squares -
***p0.1%
Based on proven herbicide x year interaction, it was evaluated stability parameters for each herbicide for grain yield of durum wheat with relation to years (Table 42). It was calculated the stability variances ıi2 and Si2 of Shukla, the ecovalence Wi of Wricke and the stability criterion YSi of Kang. Stability variances (ıi2 and Si2) of Shukla, which recorded respectively linear and nonlinear interactions, unidirectional evaluate the stability of the variants. These variants which showed lower values are considered to be more stable because they interact less with the environmental conditions. Negative values of the indicators ıi2 and Si2 are considered 0. At high values of either of the two parameters - ıi2 and Si2,
100
the variant are regarded as unstable. At the ecovalence Wi of Wricke, the higher are the values of the index, the more unstable is the variant.
Table 42 Stability parameters of herbicide Glyphosan for grain yield with relation to years Variants Stages of Cultivars treatment with Glyphosan
ത
ıi 2
Si2
Wi
YSi
4810
-93.4
276.5
501.3
4+
4388
4595.2**
4938.7**
5189.8
-10
4734
-78.8
-419.3
515.9
3+
Ripening
4833
334.3
261.9
929.0
6+
Control
4588
-10.2
328.4
1199.5
4+
4103
9577.9**
5169.7**
10787.6
-10
4526
-133.4
-501.8
1076.3
3+
4598
243.3
350.9
1453.0
6+
Control
Victoria
Predel
Milk development Dough development
Milk development Dough development Ripening
On this basis, using the first three parameters of stability, it is found that the most unstable is the variant with treatment of herbicide Glyphosan during milk development stage. In this variant, values of stability variance ıi2 and Si2 of Shukla and ecovalence Wi of Wricke are the highest and mathematically proven. The reason for this high instability is the greater variation in grain yields during different years. To evaluate the complete efficacy of each variant should be considered as its effect on grain yield of durum wheat and its stability - the reaction of wheat to this variant during the years. Valuable information
101
about the value of technologic value of the variant give the stability criterion YSi of Kang for simultaneous assessment of yield and stability, based on the reliability of the differences in yield and variance of interaction with the environment. The value of this criterion is experienced that using nonparametric methods and warranted statistical differences we get a summary assessment aligning variants in descending order according to their economic value. Generalized stability criterion YSi of Kang, taking into accounts both the stability and value of yields gives a negative assessment of the variant with treatment of herbicide Glyphosan during milk development stage. According to this criterion, technologically the most valuable appears the variant with treatment of herbicide Glyphosan during ripening stage. This variant combine high levels of grain yield and high stability of this index during the years. From the viewpoint of technology for durum wheat growing, high rating also has the variant with treatment of herbicide Glyphosan during dough development stage. It combines relatively good grain yields with high stability during the years of the investigation.
4.4. Structural elements of yield In order to explain changes in grain yield, some of the structural elements that determine it are examined (Table 43 and 44). Differences in the efficacy and selectivity of herbicide Glyphosan during different durum wheat stages result in changes in the values of the spike length, number of spikelets per spike, number of grains per spike, and grain weight per spike of main and second tiller. These differences are mathematically proven in the analysis of variance. 102
Table 43 Influence of some herbicide Glyphosan on structural elements of the yield of main tiller (mean 2008 - 2010) Variants
Cultivars
Victoria
Predel
Stages of treatment with Glyphosan
Spike length, cm
Spikelets per spike, number
Grains per spike, number
Grain weight per spike, g
Control
7.3
20.8
46.6
2.30
Milk development Dough development
7.0
19.6
44.8
1.06
7.1
20.4
45.8
2.12
Ripening
7.3
20.6
46.6
2.22
Control
8.4
21.6
49.8
2.26
Milk development Dough development
8.0
20.2
47.2
1.88
8.3
20.8
48.4
2.06
8.4
21.6
49.6
2.30
LSD 5 %
0.6
1.4
3.0
0.20
LSD 1 %
1.1
2.3
5.5
0.31
LSD 0.1 %
1.8
3.7
7.6
0.43
Ripening
The results of the structural analysis of spikes of main and second tillers in cultivars Victoria and Predel show that the changes in grain yield in the above-mentioned variants are mostly due to changes in the grain weight per spike. The reduction of this indicator is greatest in both spikes – of the main and the second tillers by treatment with Glyphosan during milk development stage, The impact of the herbicide on the spike length and spikelets number per spike and grains number per spike is significantly less or does not affect proven on these structural elements of the yield.
103
Table 44 Influence of some herbicide Glyphosan on structural elements of the yield of second tiller (mean 2008 - 2010) Variants
Cultivars
Victoria
Predel
Stages of treatment with Glyphosan
Spike length, cm
Spikelets per spike, number
Grains per spike, number
Grain weight per spike, g
Control
6.7
19.4
32.8
1.28
Milk development Dough development
6.3
18.4
30.2
0.98
6.4
19.0
31.8
1.10
Ripening
6.6
19.6
32.8
1.26
Control
7.5
19.2
33.6
1.20
Milk development Dough development
7.1
18.0
31.2
0.84
7.2
18.4
32.4
1.06
7.4
19.4
33.4
1.18
LSD 5 %
0.5
1.3
2.8
0.16
LSD 1 %
1.0
2.1
5.2
0.24
LSD 0.1 %
1.7
3.5
7.4
0.34
Ripening
4.5. Grain quality indicators The main task with regard to the quality indicators in the present investigation is to establish the variation of basic physical and biochemical parameters of the grain of two durum wheat cultivars, depending on the dynamics of the climatic factors and the total herbicide Glyphosan used during three durum wheat stages. The grain quality of the wheat, including the durum, is formed under the influence of three groups of factors. On the one hand, the natural conditions under which it is grown are important. On the other hand, high 104
quality grain is essential for the cultivation of cultivars with high technological indicators. On a third side, the proper application of the main agrotechnical measures - proper choice of predecessor, timed and quality sowing, optimal fertilization, weed control, diseases and pests, timely and quality harvesting is very important. The 1000-grain weight characterizes their obesity and is an indirect indicator of the yield of semolina in durum wheat. The higher 1000 grains weight results in a higher yield of semolina when grinding the grain. The lowest values of1000 grain weight in is recorded in untreated controls (Table 45). Treatment with herbicide Glyphosate during the milk development stage reduces the 1000 grain weight by 6.0 % for cultivar Victoria and by 7.2 % for cultivar Predel. The applying of herbicide Glyphosan during dough development and ripening stages do not have a proven effect on this indicator, although there is some reduction over the control. In these two variants the values of the indicator are above the requirements of the standard. Test weight characterizes the density of the grain and is one of the important technological parameters. Usually with increasing nitrogen rate specific weight decreases. This is associated with the preparation of a more lax tissue cell at a high nitrogen fertilizer, especially under dry conditions. Uses of herbicide Glyphosan not adversely affect the test weight of the grain, although there is some reduction by treatment during milk development stage. It retains its high levels characteristic of durum wheat all variants except untreated control have test weight over 85 kg. Grain vitreousness of durum wheat is one of the most important quality indicators. It gives an idea of the grain consistency, the protein and carotenoid content, the semolina yield. From the vitreousness grains, more
105
Table 45 Influence of herbicide Glyphosan on physical properties the grain (mean 2008 - 2010) Variants Cultivars
Victoria
Predel
1000 grain
Test weight,
Vitreousness,
weight, g
kg
%
Control
50.4
87.0
82.2
Milk development Dough development
47.4
85.5
79.2
52.2
87.5
80.8
Ripening
52.8
87.5
82.0
Control
50.2
88.5
86.6
Milk development Dough development
46.6
86.8
83.8
51.8
88.7
85.0
52.6
88.3
86.4
LSD 5 %
2.8
3.1
4.6
LSD 1 %
4.0
3.8
5.9
LSD 0.1 %
5.3
4.7
7.4
Stages of treatment with Glyphosan
Ripening
seedlings are obtained more semolina than from the flour grains. Vitreousness grains have a higher content of protein and gluten, i.e., they have better milling, bakery, pasta and sowing qualities. Grain vitreousness is genetically determined cultivar mark that is significantly influenced by growing technology, but primarily depends on weather conditions. Vitreousness is not affected by herbicide Glyphosan, although some reduction over the control and variation in the different years is reported. In any case, it has values above the requirements of international standards for
106
more than 75 % vitreousness. In all variants, the vitreousness is high - over 80 %, which is characteristic not only for the tested cultivars Victoria and Predel, but also for the other Bulgarian durum wheat cultivars. The keeping the physics properties of the grain (1000 grain weight, test weight and vitreousness) high and stable guaranteed good mill qualities and high semolina output. Other indexes included in the investigation characterized the biochemical properties of the grain from the different variants as raw material for the pasta production. The protein quantity and the wet and dry gluten quantities are one of the most important indexes, leading to pasta with a good culinary quality. To produce high quality pasta, durum wheat grain should contain over 12 % protein combined with high gluten content. The protein quantity is definitely by cultivar, but it varies depending on weather conditions and the agrotechnology. The data show that protein content decrease by treatment during milk development stage (Table 46). Despite the negative correlation between grain yield and grain quality, treatment with herbicide Glyphosan during milk development stage results in low grain yield and low protein content in both tested cultivars. Wet and dry gluten quantities are an important element of the quality characteristics of the grain. Pasta properties of grain are largely dependent on its physio-chemical properties. Similar to protein content, climatic factors and different agro-technical practices, and also weed control affects wet and dry gluten contains. In the best gluten, the ratio of wet to dry gluten should be 2.5 - 3 to 1. The obtained data show that treatment with Glyphosan during milk development stage reduces the gluten contain. Treatments during dough development and ripening stages do not cause mathematically proven 107
Table 46 Influence of herbicide Glyphosan on biochemical properties the grain (mean 2008 - 2010) Variants Cultivars
Victoria
Predel
Gluten, %
Stages of treatment with Glyphosan
Protein, %
Control Milk development Dough development
Wet
Dry
13.95
27.2
10.0
13.29
23.4
8.6
13.62
25.9
9.7
Ripening
13.78
27.2
9.8
Control
14.27
28.8
10.9
Milk development Dough development
13.76
24.0
8.9
13.94
26.4
9.9
14.27
28.7
10.8
LSD 5 %
0.44
3.6
1.2
LSD 1 %
0.51
5.1
1.8
LSD 0.1 %
0.67
7.7
2.6
Ripening
changes in values of wet and dry gluten contents. These two variants are over the standard requirements about the wet gluten quantity - more than 25 %. The ratio between wet and dry gluten (2.5 - 3 to 1) remains unchanged and favorable for producing high quality pasta. The differences in the biochemical properties of the grain are due to the changes in the speed and nature of the physiological and biochemical processes in plants occurring under the influence of treatment with herbicide Glyphosan.
108
4.6. Sowing properties of seeds One of the important conditions for obtaining a normal crop and a good harvest is the use of quality seeds. Apart from the high-yield cultivar which is resistance to diseases and pests, it must have the necessary sowing properties, the main of which are high germination energy and seed germination. Germination energy is one of the most important characteristics of the sowing properties of the seed. The low germination energy is the reason for slower development of primary roots and coleoptile after seed germination and is associated with later germination in field conditions, less tempering of plants and a higher risk of frost in the winter. Its lead to lower grain yields. Germination is the most important index who characterizing the sowing properties of the seed. At low laboratory germination sowing should be done with higher sowing rate, which increases the cost production. The obtained results (Table 47) show that the treatment of the durum wheat with herbicide Glyphosan during the milk development stage reduces germinative energy and seed germination in both durum wheat cultivars - Victoria and Predel. The application of Glyphosan during dough development and ripening stages does not lead to mathematically proven changes in the values of these two parameters. The obtained results for germination energy and seed germination are a prerequisite continue to investigate the effect of herbicide Glyphosan on initial intensity of the growth of seeds, expressed by the length of roots and coleoptiles. It was found that effect of herbicide Glyphosan on length of roots is stronger than effect on length of coleoptiles. Inhibition of the herbicide when it treated during milk development stages leads to poor
109
rooting of young plants, decrease their resistance to cold and increase risk of frost damages during winter months.
Table 47 Influence of herbicide Glyphosan on sowing properties of the seeds (mean 2008 - 2010) Variants Stages of treatment Cultivars with Glyphosan
Victoria
Predel
Length, cm Germinative Germination Coleoptile energy, % %
Root
Waste grain, %
Control
94
97
14.47
20.19
8.3
Milk development Dough development
80
91
10.25
16.61
13.3
90
96
13.51
19.03
9.8
Ripening
91
97
14.34
19.66
9.0
Control
94
98
13.83
20.06
8.8
Milk development Dough development
81
92
10.69
17.17
14.1
91
97
12.90
19.37
10.2
Ripening
92
97
13.59
19.75
9.5
7.3
5.2
2.1
2.4
4.3
LSD 5% LSD 1%
8.9
6.7
3.5
3.9
5.2
LSD 0.1%
10.2
8.1
4.9
5.7
6.6
At the evaluation of the sowing characteristics we have to consider not only the characteristics of the sowing seeds but also the quantity of the waste grain (siftings) which are gained at the preparation of these seeds. Treatment of durum wheat cultivars Victoria and Predel with herbicide Glyphosan during milk development stage leads to a increasing in the 110
quantity of waste grain. A bigger quantity of waste grain leads to higher cost of the seed and decreases the economic impact of seed production of durum wheat. Decreases in the values of germination energy and laboratory seed germination, decrease the intensity of the initial growth, expressed by the length of the root and coleoptile at germination and the increase in the quantity of waste grain under the influence of Glyphosan treatment are explained by the depressing effects on growth and development of the durum wheat during its vegetative period.
111
V. CONCLUSIONS During 1-st stem node stage of durum wheat can to be used the antibroadleaved herbicides Arat, Biathlon, Derby super, Mustang, Weedmaster, Secator, Lintur, Akurat, Akurat extra, Eagle, Starane, Sanafen, Dicotex and Herby. These herbicides do not have a negative influence on grain yield. The most unstable are herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Herbaflex and Herby. Their selectivity to durum wheat is influenced most strongly by weather conditions during the vegetation period. From the viewpoint of technology for durum wheat growing, during -st
1 stem node stage technologically the most valuable are herbicide Derby super, Arat, Biathlon, Secator, Akurat, Akurat extra and Lintur. They combine high grain yield with high stability with relation to different years. The herbicides Granstar, Granstar super, Ally max, Sunsac, Logran and Herbaflex can not to be used during 1-st stem node stage of durum wheat. During 2-nd stem node stage of durum wheat can to be used the antibroadleaved herbicides Arat, Biathlon, Derby super, Mustang, Secator, Lintur, Akurat, Akurat extra, Starane, Dicotex and Herby. These herbicides do not have a negative influence on grain yield. The most unstable are herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Eagle, Herbaflex and Herby. Their selectivity to durum wheat is influenced most strongly by weather conditions during the vegetation period. From the viewpoint of technology for durum wheat growing, during 2
-nd
stem node stage technologically the most valuable are herbicide Derby 112
super, Arat, Biathlon, Secator, Akurat, Akurat extra and Lintur. They combine high grain yield with high stability with relation to different years. The herbicides Granstar, Granstar super, Ally max, Sunsac, Weedmaster, Logran, Eagle and Herbaflex can not to be used during 2-nd stem node stage of durum wheat. During 3-rd stem node stage of durum wheat can to be used the antibroadleaved herbicides Arat, Biathlon, Derby super, Secator, Lintur, Akurat, Akurat extra and Starane. These herbicides do not have a negative influence on grain yield. The most unstable are herbicides Granstar, Granstar super, Ally max, Sunsac, Logran, Eagle, Herbaflex and Herby. Their selectivity to durum wheat is influenced most strongly by weather conditions during the vegetation period. From the viewpoint of technology for durum wheat growing, during 3
-rd
stem node stage technologically the most valuable are herbicide Derby
super, Arat, Biathlon, Secator, Akurat, Akurat extra and Lintur. They combine high grain yield with high stability with relation to different years. The herbicides Granstar, Granstar super, Ally max, Sunsac, Weedmaster, Logran, Eagle, Herbaflex, Sanafen, Dicotex and Herby can not to be used during 3-rd stem node stage of durum wheat. Herbicides Weedmaster, Mustang, Logran, Eagle, Dicotxs and Herby decrease of some physical or biochemical properties of grain and should not be used during stem elongation stage of durum wheat crop for commodity production. Herbicides Arat, Biathlon, Derby super, Secator, Lintur, Akurat, Akurat extra and Starane can be applied without the risk of reducing of durum wheat grain quality.
113
During 1-st stem node stage of durum wheat none of herbicides included in investigation had negative effect on sowing characteristics of durum wheat seeds. During 2-nd and 3-rd stem node stages of durum wheat in seed production crops of durum wheat can be used herbicides Arat, Biathlon, Derby super, Mustang, Secator, Lintur, Akurat and Akurat extra. Regardless of the application period, these herbicides not proved influence on germination energy, seed germination, lengths of primary roots and coleoptile and also waste grain quantity of durum wheat. Antigraminaceous herbicides Puma super, Grasp, Topik and Hussar max when they treated in stem elongation stage of durum wheat do not influence on grain yield of the cultivars Progress and Vuzhod. Cultivars have stronger effect on grain yield than herbicides in the analysis of variance. The four herbicides treated in 3-rd stem node stage decrease grain number per spike and grain weight per spike of main tiller, but it compensate by its increase at second tiller. Changes at cultivar Progress are stronger than changes at cultivar Vuzhod. Leaf area index of main tiller is decreased by use of herbicides Puma super, Grasp, Topic and Hussar max during 3-rd stem node stage on both durum wheat cultivars. The decrease is compensated partially by other tillers. Leaf area index of second tiller does not change proven. Plant height of main tiller of cultivar Progress decreases by use of herbicides Puma super during all three stages of applying, and herbicide Hussar max - only by applying during 3-rd stem node stage. The use of herbicide Topic during 3-rd stem node stage decreases the height of second tiller only in cultivar Progress. 114
Plant height of main tiller of cultivar Vuzhod decreases only by applying with herbicide Puma super during 3-rd stem node stage. The use of herbicides Puma super, Grasp, Topic and Hussar max during stem elongation stage degrades the harvest index and the grain: straw ratio. Herbicides Grasp, Topic and Hussar max should not be used in cultivar Vuzhod during 3-rd stem node stage because they reduce gluten content and increase gluten stretchability. During 1-st stem node stage can be applied all of four herbicides at the two cultivars. They do not influence of germinative power and seed germination of durum wheat sowing-seeds, of root and coleoptile length and waste grain. During 2-nd stem node stage can be applied Puma super, Grasp and Topik at cultivar Progress; and those herbicides plus Hussar max at cultivar Vuzhod. During 3-rd stem node stage can be applied Topik at cultivar Progress only. Antigrass herbicides cannot be applied in this stage at cultivar Vuzhod for sowing-seeds, because they decrease seed germination. Herbicide efficacy is the highest by the tank-mixtures Traxos + Lintur and Axial + Bromotril, followed by the combined herbicide Axial one. Treatment in stem elongation stage with herbicide Axial one and herbicide tank-mixtures Axial + Lintur, Axial + Logran, Axial + Bromotril and Traxos + Lintur lead to weak phytotoxicity on the durum wheat. Grain yield is the highest by the mixture Traxos + Lintur during tillering stage and by the mixture Axial + Bromotril during stem elongation stage.
115
Changes in grain yield due to changes in the grain number per spike and grain weight per spike in the main and second tiller. The use of combined herbicide Axial one and four tank-mixtures between antigraminaceous and antibroadleaved herbicides do not lead to negative changes in physical properties of the durum wheat grain and sowing properties of the durum wheat sowing-seeds. Treatment with herbicide Glyphosan during milk development stage of the durum wheat significant decreases the grain yield - by 8.8 % in cultivar Victoria and by 10.6 % in cultivar Predel. Application of the herbicide during dough development and ripening stages does not lead to mathematically proven decrease in grain yield. The grain yield is the most stable at the variant with Glyphosan treatment during ripening stage. Technological the most valuable are the variants with application of herbicide Glyphosan during dough development and ripening stages. They combine good grain yields with good stability with relation to different years. Changes in grain yield due to the biggest degree of change in the grain weight per spikes of the main and second tillers. Treatment with Glyphosan during milk development stage decreases the 1000 grain weight, protein content, and wet and dry gluten contents. Application of Glyphosan during this stage decreases germinative energy and seeds germination, reduces the length of the roots and the coleoptile and increases the waste grain quantity.
116
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ACKNOWLEDGEMENTS The author expresses his acknowledgements to Zlatitsa Ivanova Goneva, without whose devoted and invaluable help during carrying out the experimental works, it would not be possible to write this Monograph.
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PREFACE ................................................................................................................................ 1 ȱ,1752'8&7,21 ................................................................................................................ 2 ȱȱ385326($1'7$6.62),19(67,*$7,21 ............................................................ 14 ȱȱȱ0$7(5,$/6$1'0(7+2'6 ..................................................................................... 17 ȱ95(68/76$1'',6&866,21 ...................................................................................... 26 V. CONCLUSIONS ............................................................................................................. 112 9ȱ5()(5(1&(6 .............................................................................................................. 117 ACKNOWLEDGEMENTS ................................................................................................. 132
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