Legume Research, 41(2) 2018 : 287-292
AGRICULTURAL RESEARCH COMMUNICATION CENTRE
Print ISSN:0250-5371 / Online ISSN:0976-0571
www.arccjournals.com/www.legumeresearch.in
Effect of row spacing and sowing time on seed yield, quality parameters and nutrient uptake of guar [Cyamopsis tetragonoloba (L.) Taub] in semi arid climate of southern Telanagana, India A.V. Ramanjaneyulu*1, A. Madhavi2, T.L. Neelima3, P. Naresh1, K. Indudhar Reddy1 and A. Srinivas1 Regional Agricultural Research Station, Prof. Jayashankar Telangana State Agricultural University, Palem - 509 215, Nagarkurnool, Telanagana, India. Received: 05-09-2016 Accepted: 01-12-2016 DOI: 10.18805/lr.v0i0.7599 ABSTRACT A field experiment was conducted during kharif 2013 and 2014 to study the effect of row spacing and sowing time on seed yield, galactomannan and protein content and nutrient uptake of guar in semi arid climate of Southern Telangana. The crop sown at row spacing of 30 cm recorded significantly higher seed yield than that of 45 cm and 60 cm spacing. Production and rainfall use efficiency and harvest index besides growth and yield attributes, galactomannan and protein yields, N, P and K uptake were also significantly higher at 30 cm spacing. Sowing of guar during first or second fortnight of July resulted in significantly higher seed yield than first fortnight of August sowing. Production efficiency, plant height, number of clusters plant-1 and protein yield followed the similar trend of seed yield. Negative relationship was observed between galactomannan content and sowing time. Though powdery mildew infection was higher in early sown crop and close crop spacing, higher plant population and biomass production resulted in higher seed yield of guar when compared to late sown crop and wider spacing. Key words: Galactomannan, Guar, Nutrient uptake, Protein, Sowing time, Spacing. INTRODUCTION Guar [Cyamopsis tetragonoloba L. (Taub)] is a self pollinated arid leguminous herb with deep root system and drought resistance. It is cultivated as a rainfed crop in the dry habitats (Rakesh et al., 2011). Being a leguminous crop, it enriches soil fertility through atmospheric N fixation (Elsheikh and Ibrahim, 1999) and contributes maximum towards soil nitrogen. The crop is cultivated primarily for vegetable, seed, fodder and green manure in several countries. Besides, guar pods are a very good source of vitamin A, calcium, iron, phosphorus and ascorbic acid, thus add to its nutritional value. It has great recognition as an industrial crop in the recent times for its high protein content (30-33%) and ‘galactomannan’ content (22-33%) (Fabio Gresta et al., 2013) and for guar meal (Singh et al., 2014). India ranks first among the guar producing countries and contributes around 80% share of the worlds’ total production (Rakesh et al., 2011). Efforts are on to introduce guar crop in semi-arid tropical (SAT) climate of India under rainfed conditions especially for galactomannan purpose. The sowing time is an important non-monetary input that influences vegetative and reproductive growth periods,
length of growing season and growing degree days, pests and disease incidence thus finally seed quality and yield. Early sowing can accelerate establishment and make full use of the growing season and make it competitive for weed control. It helps for production of deeper roots than late sown crops, allowing access to moisture later in the season. It increases biomass and allows a longer grain filling period for high yield potential. It also assumes importance in view of shift in rainfall pattern following global climate change. Spacing is another important non-monetary agronomic practice which ensures maintenance of optimum crop stand, efficient utilization of natural resources like light, space, water and nutrients by the crop canopy thus higher productivity besides saving of seed and reduction in cost of cultivation. A field experiment was carried out to explore the possibility of introducing the guar into semi-arid tropical rainfed environment and to identify suitable spacing and sowing time for augmenting the productivity and quality. MATERIALS AND METHODS A field investigation was carried out in Southern Telangana during kharif 2013 and 2014 under rainfed conditions to find out optimum row spacing and sowing time
*Corresponding author’s e-mail:
[email protected] 1 Regional Agricultural Research Station, Prof. Jayashankar Telangana State Agricultural University, Palem-509 215, Mahabubnagar district, Telanagana, India. 2 Radio Tracer Laboraory, Agricultural Research Institute, Prof. Jayashankar Telangana State Agricultural University, Rajendranagar, Hyderabad - 500 030. 3 Agricultural Polytechnic, Prof. Jayashankar Telangana State Agricultural University, Palem -509 215, Mahabubnagar district, Telanagana, India.
288
LEGUME RESEARCH- An International Journal
and their impact on seed yield and quality of guar. The soil of the experimental site was Alfisol with a pH of 6.84, EC of 0.14 dSm-1, low in available nitrogen and, high in available phosphorus and potassium. The experiment was laid out in split plot design with three row spacings viz. S1: 30 cm; S2: 45 cm; S3: 60 cm in main plots and three sowing times viz., D1: First fortnight of July; D2: Second fortnight of July; D3: First fortnight of August in sub plots and replicated thrice. An intra-row spacing of 15 cm was maintained for all the treatments. Guar variety “RGC-936” was used as test variety. A net plot size of 4.5mx5m (22.5m 2) was maintained. A fertilizer dose of 20 kg N, 40 kg P2O5 and 30 kg K2O ha-1 through urea, single super phosphate and muriate of potash was applied as basal. Seed inoculation with Rhizobium biofertilizer was done as guar is a non-traditional crop in the area. The crop was kept weed free by spraying a pre-emergence herbicide pendimethalin @ 0.75 kg a.i ha-1 followed by two hand weedings at 30 and 45 days after sowing. Harvesting was done by uprooting the plants from net plot of each treatment followed by drying in the sun for a week and then pods were threshed to get seed. Seed from each net plot treatment was weighed and converted into t ha-1. The high rainfall coupled high relative humidity and low evaporation favoured the outbreak of powdery mildew during 2013 as compared to normal rainfall, low humidity and high evaporation recorded during corresponding period in 2014. Pre-spray powdery mildew incidence count with regard to number of total leaves was carried out at 60 DAS (days after sowing). Post-spray count in respect of infected leaves was done one week after spraying wettable sulphur @ 3 g lit-1. Percentage infected leaves was calculated as a function of infected leaves and number of total leaves (Sharma, 1984). Production efficiency was calculated by dividing the seed yield by duration and was expressed as t ha-1 day-1. Rainfall use efficiency was calculated by dividing the seed yield by
effective rainfall received during the crop period. Pre and post harvest soil available N, P, and K and their content in straw and seed samples were determined by the standard procedures. Nutrient uptake by seed or straw was calculated as a function of nutrient content (%) and grain or straw yield. The protein content in the seed was calculated by multiplying nitrogen concentration with a factor 6.25 (AOAC, 1960). The percent galactomannan (galactomannan) in the seeds was estimated by using phenol sulphuric acid method (Das et al., 1977). The galactomannan yield was calculated by multiplying the percent galactomannan in the seeds and seed yield divided by 100. The data on all growth parameters, yield attributes, yield, quality and nutrient uptake were analyzed by using F-test as per the procedure given by Gomez and Gomez (1984). RESULTS AND DISCUSSION Growth and yield attributes: Significantly higher plant population was recorded when crop was grown at a narrow spacing of 30 cm. Plant height, noumber of branches plant-1 and number of pods plant-1 were also significantly higher at 30 cm and 45 cm row spacing than at 60 cm. The percentage of leaves infected by powdery mildew was higher at 30 cm spacing than at 45 and 60 cm row spacings in both the years (Table 1). Sowing during first fortnight of July resulted in significantly taller plants with more number of clusters plant-1, while, plant population, number of branches and pods plant-1 and 1000 seed weight did not differ significantly due to sowing time. Early sowing (July first fortnight) encouraged the incidence of powdery mildew as compared to late sowing. Yield, harvest index, rainfall use efficiency and production efficiency: The seed yield of guar was significantly higher during 2014 as compared to 2013 thus recorded significantly higher rainfall use efficiency and
Table 1: Effect of row spacing and sowing time on growth and yield attributes and percentage leaves infected by powdery mildew in guar Treatment
Row spacing S1: 30cm S2: 45cm S3: 60cm SEm± CD (p=0.05) Sowing time D1: I FN July D2: II FN July D3: I FN Aug SEm± CD (p=0.05) FN: Fortnight
Plant Population (x105 ha-1)
Plant No. of height branches (cm) plant-1
No. of clusters plant-1
No. of 1000 pods seed plant-1 weight (g)
Percentage of leaves infected bypowdery mildew 2013 2014 Before After Before After spray spray spray spray
2.169 1.439 1.083 0.005 0.018
68.9 65.8 43.3 1.7 5.7
5.98 5.41 3.60 0.28 0.93
13.5 14.7 3.8 0.37 1.2
50.9 43.6 17.1 2.63 8.57
31.3 31.1 31.9 0.20 0.70
76.70 72.20 67.77 3.07 NS
25.13 19.88 16.74 0.95 2.92
63.51 60.47 56.97 1.59 4.92
20.41 16.30 13.50 1.15 3.54
1.557 1.569 1.566 0.062 NS
60.1 61.7 56.2 1.1 3.3
4.78 5.40 4.82 0.23 0.68
11.4 9.93 10.7 0.5 1.4
40.6 38.2 32.7 3.86 11.26
31.6 31.8 31.1 0.30 0.90
78.32 73.66 64.69 3.63 NS
23.00 19.63 19.12 0.75 2.93
65.69 62.02 53.23 3.09 NS
18.80 16.30 15.11 0.99 NS
Row spacing of 30 cm recorded significantly higher seed yield of 0.742 t ha-1 as compared to 45 cm (0.591 t ha-1) and 60cm (0.225 t ha-1). Similar trend was observed in rainfall use efficiency and production efficiency also. Further 30 cm and 45cm row spacings being at par were significantly superior to 60 cm spacing in terms of straw yield. The main reason for significantly higher seed yield in 30 cm was significantly higher plant population against lower population at 45 cm and 60 cm. Further, higher harvest index and significantly taller plants with more number of branches, clusters and pods plant-1 (Table 3) also contributed for higher seed yield at 30 cm spacing. Earlier, Sharma et al. (1984) recommended inter row spacing of 30 cm for unbranched varieties of guar and 45 cm for branched ones for achieving significantly higher seed yield. Our results are also in agreement with the findings of Jagtap et al., (2011) and Lal et al., (2012) who suggested a narrow row spacing of 30-45 cm with 15 kg ha-1 seed rate rather than wider spacing of 60 cm for improved growth and yield under rainfed conditions of tropical climate. Ayub et al., (2011) reported significantly higher green forage and dry matter yield with decrease in spacing and increase in seeding density. The early sown crop (D1: July first fortnight) recorded significantly higher seed yield of 0.564 t ha-1 as compared to that of late sown crop (D3: August first fortnight: 0.473 t ha-1), but, was at par with that of crop sown during July second fortnight (0.520 t ha-1). Significantly hihger number of clusters plant -1 (Table 3) might be attributed for higher seed yield of guar sown during July first fortnight. Production efficiency followed the similar trend. However, sowing time did not exert significant influence on plant population, number of branches and pods plant-1, harvest index and rainfall use efficiency. Higher values of harvest index were recorded during 2014 than 2013 for the corresponding sowing time and it was mainly due to higher seed yield during 2014 (Table 2). Rogers (1973) recommended sowing on 5th July for higher seed yield,
289
RUE: Rainwater use efficiency FN: Fortnight Effective rainfall received during crop growth period: 2013: D1-568.73 mm in 44 rainy days D2-472.58 mm in 35 rainy days D3: 458.02 mm in 31rainy days 2014: D1-309.9 mm in 17 rainy days D2- 285mm in 16 rainy days D3: 252.15 mm in 16rainy days
production efficiency. Straw yield of guar followed the similar trend (Table 2). It was mainly due to less powdery mildew incidence, better growth and productive attributes during 2014 than 2013. Though harvest index was higher during 2014 (26%) than 2013 (17%) it did not differ significantly (Table 2). The significant variation between years can be explained by fluctuations in rainfall and humidity. High rainfall coupled with high relative humidity and less evaporation prevailed in the year 2013 as compared to the corresponding period during 2014, encouraged severe incidence of powdery mildew, thus drastically affected the seed and straw yield and harvest index during 2013. Saharan and Saharan (2004) too observed that high temperatures and low relative humidity are able to inhibit Alternaria cyamopsidis disease, that limited the grain production in rainy season.
Table 2: Effect of row spacing and sowing time on seed and straw yield, rainwater use efficiency and production efficiency of guar
Volume 41 Issue 2 (April 2018)
290
LEGUME RESEARCH- An International Journal
galactomannan and protein contents as compared to early and late sowings. Yousif (1984) also suggested first week of July as the best time of sowing guar under tropical climatic conditions. Jagtap et al., (2011) reported significantly higher seed, straw and biological yield due to sowing during 28th MW (9-15th July) under agroclimatic conditions of Deccan plateau. Powdery mildew incidence: The percentage infected leaves by powdery mildew was higher during 2013 than in 2014 (Table 1). It was mainly due to high rainfall coupled with high relative humidity and less evaporation prevailed in the year 2013 as compared 2014, which encouraged severe incidence of powdery mildew, drastically reducing the seed and straw yield and harvest index. Irrespective of the year, percentage infection due to powdery mildew was higher under early sown conditions as compared to August sowings, however, high straw (biomass) yield obtained during early sowing period compensated the loss and resulted in higher seed yield. Though powdery mildew incidence was higher at narrow and medium spacing, higher plant population and biomass production resulted in higher seed yield of guar than at wider spacing (60 cm). Quality parameters: Galactomannan yield was significantly higher with 30cm row spacing as compared to that of wider spacings (Table 3). This was mainly due to significantly higher seed yield and higher galactomannan content. Adoption of 30cm row spacing significantly outyielded wider spacings in terms of protein yield too. However, spacing failed to show significant effect on protein yield and galactomannan content. Though galactomannan content was significantly higher under late sown conditions the galactomannan yield was significantly higher under early sown conditions. First fortnight of July sowing was at par with second fortnight of July, but, significantly superior to first fortnight of August in respect of protein yield. The reasons for better galactomannan and protein yields under early sown conditions was significantly higher seed yield.
Kumar and Singh (2002) and Fabio Gresta et al., (2013) too observed negative relationship between seed yield and galactomannan content but positive relationship between seed yield and galactomannan yield. Nutrient uptake and soil nutrient balance: Guar crop grown at the narrow row spacing of 30 cm removed significantly higher amount of N, P and K than that of wider spacings. It was mainly due to significantly higher seed yield, harvest index and production efficiency at narrow spacing. Significantly higher amount of N was removed by the crop when it was sown during first fortnight of July. However, it was at par with second fortnight of July and significantly superior to first fortnight of August. On the otherhand, P and K uptake was not significantly affected by sowing time. Considerable reduction in post harvest soil available N, P and K was observed due to crop geometry and sowing time as compared to their corresponding initial values. However, the post harvest soil chemical properties like pH, EC, available N, P2O5 and K20 did not differ significantly due to either spacings or sowing time except available N due to spacing (Table 4). Significantly higher amount of N was left over in the soil after two years of experimentation when the crop was grown with wider spacing as compared to that of 45 cm. It was mainly due to less amount of N removed by the crop grown at 60 cm spacing. Correlation studies: Among growth and yield traits studied, plant height and number of pods plant-1 were found to be two most important parameters that influenced the guar seed yield (Table 5). Their correlation with seed yield was positive and highly significant. These two parameters might have influenced the seed yield through number of branches plant-1 and number of clusters/plant-1. In case of quality parameters, galactomannan content had higher positive and significant correlation with seed and galactomannan yields, while, protein content had positive but insignificant correlation with protein yield. However, highly significant positive correlation was observed between protein yield and seed yield. It means, any agronomic practice that can increase galactomannan or
Table 3: Effect of row spacing and sowing time on quality parameters and economics of guar (Pooled data of 2013 and 2014) Treatment Row Spacing S1: 30 cm S2: 45 cm S3: 60 cm SEm± CD (p=0.05) Sowing time D1: I FN July D2: II FN July D3: I FN Aug SEm± CD (p=0.05) FN: Fortnight
Galactomannan Yield (t ha-1)
Protein content (%)
28.4 27.7 26.5 0.2 0.6
0.211 0.164 0.060 0.012 0.016
32.0 32.2 32.3 0.2 NS
0.240 0.191 0.072 0.007 0.023
26.9 27.6 28.2 0.1 0.4
0.154 0.146 0.135 0.010 NS
32.3 32.3 32.0 0.5 NS
0.181 0.169 0.152 0.010 0.030
Galactomannan Content (%)
Protein yield (t ha-1)
10.0 7.7 4.4 0.4 1.3 7.5 7.5 7.2 0.4 1.1
57.0 53.0 47.5 2.5 7.3
P (kgha-1)
69.4 58.5 29.6 2.0 6.6
N (kgha-1)
36.1 36.6 32.0 1.7 4.8
43.2 37.4 24.3 1.4 4.5
K (kgha-1)
6.81 6.78 6.77 0.02 0.05
6.80 6.79 6.77 0.02 0.07
pH
Plant height (cm)
Significance * p < 0.05,
** p
