Effect of weed management on nutrient utilization by chickpea and weeds under Jatropha based agroforestry

Abstract

A field experiment was conducted at Research Farm, Department of Forestry, JNKVV, Jabalpur during Rabi season 2019-20 to find out the effect of weed management on nutrient utilization by Chickpea and weeds under Jatropha based Agroforestry. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications and 12 herbicidal treatments consisted of Pendimethalin 1000 g ha-1, Imazathaper 900 g ha-1, Atrazin 1000 g ha-1, Metribuzin 300 g ha-1, Oxyflorfen 100 g ha-1, Pendimethalin 500 g ha-1 fb Imazathaper 450 g ha-1, Pendimethalin 500 g ha-1 fb Oxyflorfen 50 g ha-1, Metribuzin 150 g ha-1 fb Oxyflorfen 50 g ha-1, Atrazin 500 g ha-1 fb Metribuzin 150 g ha-1, Imazathaper 450 g ha-1 fb Atrazin 500 g ha-1, hand weeding (30 DAS) and Weedy check (control). The nutrient absorption by crop and weeds is significantly influence by different herbicidal treatments. The result revealed that there were different variations in nutrients absorption by weeds. The highest nutrient absorption by chickpea seed was observed in hand weeding (42.6: 9.22: 19.2) and minimum was in weedy check (14.3: 2.22: 7.25). The highest nutrient absorption by stover was observed in hand weeding (44.4: 10.6: 32.8) and minimum was in weedy check (23.7: 2.93: 18.2). The maximum nutrient absorption of hand weeding (87.07: 19.85: 50.48) and minimum was in weedy check (38.15: 5.16: 24.85) of total (seed + stover). Among different herbicidal treatments application of Pendimethalin 1000 g ha-1 was found the highest (66.37: 13.85: 42.29) and lowest was in Imazathaper 900 g ha-1 (49.12: 7.06: 29.:39) of total (seed + stover). Weedy check recorded significantly higher nutrient absorption of weeds viz., Cynodon dactylon (4.52: 2.40: 3.46 NPK kg ha-1), Cyperus rotundus (3.03: 1.41: 7.41), Medicago arabica (24.23: 3.34: 31.33), and Vicia sativa (15.77: 2.57: 24.37). Hand weeding (30DAS) recorded significantly lower nutrient absorption by weeds viz., Cynodon dactylon (0.59: 0.28: 1.78), Cyperus rotundus (0.29: 0.11: 0.77), Medicago arabica (2.14: 0.30: 2.86), and Vicia sativa (1.46: 0.21: 2.27 K) Lower absorption of nutrient in these treatments attributed to lower weeds density and dry weight. The maximum nutrient absorption of total weeds in weedy check (47.60: 9.72: 76.67) and minimum was in hand weeding (4.48: 0.91: 7.65). Among different herbicidal treatments application of application of Imazathaper 450 g ha-1 fb Atrazin 500 g ha-1 was found the highest (21.31: 4.20: 36.51) and lowest was in Metribuzin 150 g ha-1 fb Oxyflorfen 50 g ha-1 (13.44: 3.09: 24.80).