(Galinsoga parviflora), Canadian thistle (Cirsium arvense) and ribwort plantain (Plantago lanceolata). Exudates from germinated buckwheat achenes inhibited ...
Proceedings ofthe 9th International Symposium on Buckwheat, Prague 2004
Influence of Common Buckwheat on Growth of Other Plant Species J. Kalinova. University ofSouth Bohemia, Faculty ofAgriculture, StudentskG 13, 37005 Ceske Budejovice, Czech Republic ABSTRACT
In year 2003 we observed the influence of buckwheat stand on weeds in field conditions, influence of exudates of germinated buckwheat achenes on some crops (oat, annual ryegrass, white mustard and lettuce) and differences among seven varieties of common buckwheat (Fagopyrum esculentum Moench) in these parameters. The buckwheat stand significant inhibited growth offield pennycress (Thlaspi arvense), gallant soldier (Galinsoga parviflora), Canadian thistle (Cirsium arvense) and ribwort plantain (Plantago lanceolata). Exudates from germinated buckwheat achenes inhibited root growth of annual ryegrass (Lotium multiflorum), white mustard (Sinapis alba) and lettuce (Lactuca sativa). On the contrary the growth of oat (Avena sativa) was stimulated. Tetraploid variety Ernka differed significantly (had more inhibitory effects) from the other varieties in all tests. Keywords: variety, weeds, inhibition, dry matter INTRODUCTION
Common buckwheat belong to good weed competitors (especially annual weeds) for its quickly growth (BERGLUND 1995 TOMINAGA, UEZU 1995). Therefore the crop is frequent part of crops rotation in ecological systems of farming (EDWARDSON 1996). In last, buckwheat was exploited like a suitable foregoing crop of flax by reason of growth lnhibition of quick grass (Agropyron repens L.) (OKROUHLA 1993). The inhibition of weeds is explained by competition among plants and quickly growth on the beginning of buckwheat development (ESKELSEN, CRABTREE 1995). The inhibition effect on growth another plants has habitus of buckwheat plant too. Every plant contains number of secondary metabolites that can have inhibitory effects on other plants (PROCHAZKA 1998). Exploitation of these characteristics is promising basis of weed suppression in ecological systems of farming. The aim of this contribution was to evaluate the influence of buckwheat stand on weeds in field conditions, influence of exudates of germinated buckwheat achenes on some crops and differences among varieties of common buckwheat (Fagopyrum esculentum Moench) in these parameters. MATERIAL AND METHODS
Three varieties of common buckwheat (Pyra - CZ, Emka - PL, Huszowska - PL, , Krupinka - RUS and Sumcanka - RUS) were tested in field trials (3 repetition and control with free growth weeds without buckwheat) in Ceske Budejovice (380 m above sea level, acid cambisoil, gleying, sandy loam soil) during year 2003. Soil samples (depth 0-100 mm) and aboveground biomass samples of buckwheat were taken away before buckwheat harvest. Number of plants, species composition, dry matter weight of weeds and buckwheat were evaluated on 1 m2 of all variants and repetitions. The influence of buckwheat on weed growth was evaluated only by the species that were found in minimum 10 pieces per square meter of one repetition. The influence of germinated buckwheat achenes on seed growth of selected crops (oat, annual ryegrass, white mustard and lettuce - test plant) was tested in laboratory conditions (4 repetitions and 4 variants: 21 seeds of selected crops x 21 achenes of buckwheat - rows; 21 seeds of selected crops x 21 achenes of buckwheat - spacing; 42 achenes of buckwheat; 42 seeds of selected crops). Seeds of selected weeds will used for bioassays next year. Seeds
529
Proceedings o/the 9th International Symposium on Buckwheat, Prague 2004
were surface disinfected and inserted in Petri dishes with filter paper that was moistened with 6 ml distilled water, We observed length of roots and hypocotyl after 2, 3 eventually 4 days (to development ofhypocotyl) by temperature 23±2°C. Data were evaluated using analysis of variance and Tukey test (software Statistica 6.0), RESULTS
Field pennycress (Thlaspi arvense), gallant soldier (Galinsoga parviflora), barnyardgrass (Echinochloa crus-galli), ribwort plantain (Plantago lanceolata) and Canadian thistle (Cirsium arvense) belonged to most weeds in buckwheat stand. Plants of buckwheat influenced created dry matter weight of field pennycress (F9.516, p-O.011), gallant soldier (F- 8.363, p-0,006), Canadian thistle (F-21.019, p-O,044) and ribwort plantain (F- 30.954, p-0.Ol1) statistically significant. We did not confinn influence of buckwheat stand on dry matter of bamyard grass (F- 3.707, p-O,061). Significant differences among suppressive effects of buckwheat varieties were only in created dry matter of field pennycress, when weed plants had lower weight if they developed in stands of varieties Emka a Pyra (tab. 1). Tab. 1 Dry matter of some weeds in buckwheat stand (g) Gallant soldier dif x Emka Kora Pyra Buckwheat Weeds
0.27
a
0.34 0.45 0.35 1.35
a a
b
Field pennycress dif x 0.21 a 0.44 b 0.18 a 1.40 0.27 c
Barnyard grass dif x 1.41 a 1.97 a 2,08 a 1.82 3.58 a
Canadian thistle dif x
2.22 11.81
a b
Ribwort plantain dif x
0,23 1.90
a b
Germinated buckwheat achenes significant reduced root length of ryegrass, mustard and lettuce (table 2,3,4). Exudates of germinated achenes did not have significant influence on hypocotyl growth these species. Oat roots were resistant to influence of exudates and on the contrary growth of oat hypocotyl was stimulated (table 5). It makes for a view from agricultural practice, that it is possible buckwheat growing together with oat in a mixture. We did not establish unambiguous statistically significant differences among spacing and row arrangement of seeds, therefore the roots of all species was shorter by spacing. This difference was significant by mustard roots only first and second day of cultivation. Different effects of exudates of genninated achenes of different buckwheat varieties exhibited on root length. Variety Emka caused significantly greater reduction of lettuce root growth than other varieties (table 4). Tab. 2 Root and hypocotyllength of mustard (mm)
Spacing Rows Control
Root - 1th day dif X 1.38 a 1.67 ab 1.74 b
nd
Root - 2 day dif X 5.27 a 7,05 b 10.15 c
Analysis of 2.994* 47.052** variance (MS) *p ~ 0,05, **p ~ 0,01, n.s. - non significant
530
rd
Root - 3 day dif x a 13.06 15.73 a 28.73 b 115.414**
fd
Hypocotyl - 3 day dif X 9.98 a a 11.01 a 12.80 3.624 n.s.
Proceedings a/the 9th International Symposium on Buckwheat, Prague 2004
Tab.3 Root and hypocotyllength of annual ryegrass (mm) Root 2
Spacing Rows Control
nd
x 0.18 0.18 0.43
rd
day
Root 3 day
dif
x 4.98 5.47 11.99
a a b
dif
Analysis of 27.980** 13.432** variance (MS) *p ~ 0.05, **p ~ 0.01, n.s. - non significant
Root 4 day
x 12.85 11.81 19.11
a a a
0.96 2.11 1.81
a a b
th
rd
Hypocotyl 3 day dif x
dif a
8.61 6.79 9.74
a b
12.405**
2.957 n.s
lh
Hypocoty 1 4 day dif x a
a a
2.731 n.s
Tab. 4 Root and hypocotyllength of lettuce (mm) Root 2 nd day dif x Emka Krupinka Pyra Control
0.24 0.45 0.51 058
a
ab
ab b
Root 3rd day dif x 1.79 a 2.01 ab 2.85 be 3.06 c
Analysis of 4.131** variance eMS) up ~ 0.01, n.s. - non significant
6.001 **
th
Root 4 day dif x 3.33 4.21 4.98 7.83
a b
b c
th Hypocotyl 4 day dif x 3.33 a 2.71 a 3.81 a 2.72 a
11.508**
1.156 n.s
Root 3riJ day dif x
Hypocoty13 day dif x
Tab. 5 Root and hypocoty11ength of oat (mm) Root I Spacing Rows Control
x 0.50 0.62 0.64
th
day dif
a a a
Analysis of 2.256 n.s variance eMS) up ~ 0.01, n.S. - non significant
Root 2
x 4.78 5.51 5.69
nd
day dif
a a a
0.991 n.s
14.14 19.30 19.64
a a a
1.529 n.s
rd
4.69 8.44 2.85
b c a
29.436**
ACKNOWLEDGMENTS
This work was supported by grants of the Grant Agency ofthe Czech Republic 521/03!D076. REFERENCES
BERGLUND, D. R. (1995): Buckwheat production. NDSU Extension Servise A-687. EDWARDSON, S. (1996): Buckwheat: Pseudocereal and nutraceutical. In: 1. JANICK (ed.) Progress in new eros, ASHS Press. Alexandria, VA: 195-207. ESKELSEN, S. R., CRABTREE, G.D. (1995): The role of allelopathy in buckwheat (Fagopyrum sagittatum) inhibition of Canada thistle (Cirsium arvense). Weed Science 43:70-74. OKROUHLA, M. (1993): Pestovini pohanky sete. Studijni informace, Rostlinna -ryroba 3: 47. PROCHAZKA, S., MACHACKoVA,I., KREKULE, J., SEB.A.NEK, J. (1998): Fyziologie rostlin. Academia, Praha, 484.
TOMINAGA, T., UEZU, T. (1995): Weed suppression by Buckwheat, Current Advances in Buckwheat Research: 693-697.
531
