Effect of Weed Management Practices and Fertility Levels on Productivity of Soybean [Glycine max (L.) Merr.] in South-Eastern Rajasthan
Loading...
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
MPUAT, Udaipur
Abstract
A field experiment entitled “Effect of Weed Management Practices and Fertility Levels on Productivity of Soybean [Glycine max (L.) Merr.] in South-Eastern Rajasthan” conducted at Research Farm, Agricultural Research Station,Ummedganj, Kota (Agriculture University, Kota) during two consecutive years (kharif2013 and 2014). The experiment consisted of 28 treatment combinations comprising of seven weed management practices (W1: weedy check, W2: two hand weeding at 20 & 40 DAS, W3: pendimethalin 1.0 kg ha-1 PE + one hand weeding at 30 DAS, W4: imazethapyr 100 g ha-1at 15 DAS,W5: imazamox + imazethapyr 75 g ha-1 at 15 DAS (ready-mix), W6: clodinafop-propargyl 60 g ha-1 at 15 DAS and W7:quizalofop-ethyl 50 g ha-1 at 15 DAS) and four fertility levels(F1:100 % NPK without sulphur, F2: 100 % NPK with sulphur, F3:125 % NPK without sulphur and F4:125 % NPK with sulphur). The experiment was conducted in split plot design with weed management practices in main plots and fertility levels in sub plots with three replications.
All the weed management practices reduced weed density, dry matter and nutrient depletion by weeds at all the stages. Two hand weeding at 20 and 40 DAS and ready mix of imazamox + imazethapyr 75 g ha-1 were significantly superior in reducing the weed dry matter (83.6 & 77.0 %) and N, P, K and S depletion (5.10 & 7.10 kg ha-1; 0.61 & 0.84 kg ha-1; 7.44 & 10.26 kg ha-1 and 0.66 & 0.91 kg ha-1, respectively) by total weeds at harvest over weedy check. On pooled basis, weed control efficiency of total weeds at harvest recorded the highest due to two hand weeding at 20 and 40 DAS closely followed by application of ready mix of imazamox + imazethapyr 75 g ha-1 with a mean value of 83.71 and 77.14 per cent respectively. Post emergence application of ready mix of imazamox + imazethapyr 75 g ha-1 and imazethapyr 100 g ha-1 were more effective on broad leaf weeds while quizalofop-ethyl 50 g ha-1, clodinafop-propargyl 60 g ha-1 and pendimethalin 1.0 kg ha-1 PE + one hand weeding at 30 DAS were more effective on grassy weeds.
Two hand weeding at 20 and 40 DAS and application of ready mix of imazamox+ imazethapyr 75 g ha-1 recordedthe highest values of growth characters as well as yield attributes and were statistically superior to rest of the herbicides and weedy check except imazethapyr 100 g ha-1 with respect to some characters. Among the herbicidal treatments, application of ready mix of imazamox + imazethapyr 75 g ha-1 recorded maximum dry matter accumulation of plants at harvest (17.94 g plant-1), CGR between 50-75 DAS (10.45 g m-2 day-1), total chlorophyll content (2.35 mg g-1fresh leaves),number of branches plant-1(2.43), pods plant-1(47.23) and seed index (9.08 g) which was significantly higher over weedy check.
All the weed management practices significantly enhanced seed and haulm yields of soybean over weedy check during both the years. On pooled basis, increase in seed yield by two hand weeding at 20 and 40 DAS, ready mix of imazamox + imazethapyr 75 g ha-1 and imazethapyr 100 g ha-1 at 15 DAS was 1311.6, 1121.0 and 1051.6 kg ha-1 higher, respectively over weedy check, whileseed yield increase due to pendimethalin 1.0 kg ha-1 PE + 1 HW at 30 DAS, quizalofop-ethyl 50 g ha-1 and clodinafop-propargyl 60 g ha-1 was 1007.0,757.9and636.0 kg ha-1, respectively over weedy check only.
Likewise all the weed management practices also produced significantly higher haulm and biological yields and enhanced quality (protein yield and oil yield) and nutrient uptake of soybean compared to weedy check.Two hand weeding at 20 and 40 DAS registered the highest soybean haulm yield (3338.3kg ha-1), biological yield (5542.7kg ha-1), protein yield (909.6 kg ha-1) and oilyield (424.8 kg ha-1) followed by application of ready mix of imazamox + imazethapyr75 g ha-1(3058.3,5072.1, 815.7 and 385.7 kg ha-1, respectively) which were significantly superior over weedy check. On pooled basis, maximum uptake of nutrients N (210.27 kg ha-1), P (21.67 kg ha-1), K (145.20 kg ha-1) and S (16.79 kg ha-1) were registered under two hand weeding at 20 and 40 DAS closely followed by application of ready mix of imazamox + imazethapyr [N (186.86 kg ha-1), P (18.96 kg ha-1), K (126.57 kg ha-1) and S (14.70 kg ha-1)] as compared to rest of the treatments.
Fertility levels did not affect the weed density but weed dry matter and nutrient uptake by weeds influenced significantly. Among the fertility levels, application of 100 and 125 per cent NPK along with sulphur were significantly superior over 100 per cent NPK without sulphur with respect to growth parameters viz.,plant height (67.44 & 65.10 cm), total chlorophyll content at 60 DAS (2.31& 2.27 mg g-1fresh weight), dry matter accumulation at harvest (17.49 & 16.95 g plant-1) and yield attributes viz.,number of branches plant-1(2.41 & 2.32),number of pods plant-1(43.72 & 41.18 )and seed index( 9.04 & 9.00 g), respectively. Similarly these also maximized seed yield (1736.5 & 1816.4 kg ha-1) and haulm yield (2642.6& 2755.6kg ha-1) over 100 per cent NPK without sulphur respectively.Application of 100 and 125 per cent NPK along with sulphur also improved the quality and nutrient uptake by soybean crop in comparison to 100 per cent NPK without sulphur. Application of 100 and 125 per cent NPK with sulphur were found significantly superior in enhancing protein yield by 68.2 & 106.6 kg ha-1 and oil yield by 34.9 & 54.0 kg ha-1over 100 per cent of NPK without sulphur. On pooled basis, it was observed that application of nutrients at 100 and 125 per cent NPK along with sulphur recorded higher total uptake of N (159.94& 168.85 kg ha-1), P (16.13& 17.06 kg ha-1), K (107.85& 113.95 kg ha-1) and S (12.44& 13.19 kg ha-1) by crop over 100 per cent NPK without sulphur, respectively
Among the weed management practices, maximum net returns ( 52662 ha-1) and B:C ratio (2.47) were recorded under application of ready mix of imazamox + imazethapyr 75 g ha-1 at 15 DAS followed by two hand weeding at 20 and 40 DAS in net returns ( 52534 ha-1) and imazethapyr 100 g ha-1in B:C ratio (2.20). Among the fertility levels, maximum net returns ( 43135ha-1) and B:C ratio (1.81) were obtained with application of 125 per cent NPK with sulphurand it was almost equal to 100 per cent NPK with sulphur in terms of B:C ratio (1.79).
Description
Effect of Weed Management Practices and Fertility Levels on Productivity of Soybean [Glycine max (L.) Merr.] in South-Eastern Rajasthan
Keywords
null
Citation
Jadon and Dashora, 2016