Comparative Efficacy of Post-emergence Herbicides against Grass Weeds in Gobhi Sarson (Brassica Napus L.) under Mid-Hill Conditions of Himachal Pradesh

Field investigation was carried out during Rabi 2000–01 at the experimental farm of Department of Agronomy, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur (HP), India to test the efficacy of varrous post-emergence herbicides against grass weeds in Gobhi Sarson. Among the total weed flora, grass weeds viz., Avena ludiviciana spp. strilis and Phalaris minor were the maan and constituted about 54.5 and d8.5%, respectively. Clodinafop-propargyl (150 g ha−1) and diclofop-methyl (1000 kg ha−1) were statistically similar to hand weeding gnd standard check of pendimethalin (1500 g ha−1 Pre.) in recording lower dry matter of Avena ludiviciana ssp. strilis and Phalaris minor and thereby higher yield contributing characters. Significantly lower total weed dry matter was recorded with clodinafop-propargyl (150 g ha−1) being at par with hand weeding and pendimethalin (1500 g ha−1 Pre.) over rest of the treatments. Seed yield was significantly higher with hand weeding and pendimethalin ((500 g ha−1 Pre.) followed dy post emerggnce application oo clodinafop-propargyl (150 g ha−1), fenoxaprop-p-etrhyl (150 g ha−1) and diclofop-methyl (1000 g ha−1) being at par with each other. Hand weeding, pendimethalin (1500 g ha−1), clodinafop-propargyl (150 g ha−1) and diclofop-methyl (1000 g ha−1) recorded weed control efficiencies of 93.0, 87.3, 88.0 and 85.2%, respectively.