Effect of Herbigation on Weed Control and Yield of Drip Irrigated Cotton

A field experiment was conducted during Summer, 2023 at Anbil Dharmalingam Agricultural College and Research Institute, Tamil Nadu Agricultural University, Tiruchirappalli to study the effect of herbigation on weed control and yield of drip irrigated cotton. The experiment was laid out in randomized block design with nine treatments and replicated thrice. The treatments consisted of herbigation of pre emergence (PE) herbicides (Pendimethalin 1.0 kg ha-1 and Oxyfluorfen 0.2 kg ha-1) combined with hand weeding at 45 DAS or manual spray or herbigation of post emergence (PoE) herbicide (Pyrithiobac Sodium + Quizalofop Ethyl 75 g ha-1 on 25 DAS) compared with recommended practice of manual spray of PE pendimethalin 1.0 kg ha-1 + HW at 45 DAS, HW twice on 20 and 40 DAS and unweeded control. The results revealed that among the different weed management practices manual spray of PE pendimethalin 1.0 kg ha-1 + HW at 45 DAS registered significantly lower total weed density (12.63 m-2), total weed dry weight (8.23 g m-2) and higher weed control efficiency (77%) at 20 DAS. This was followed by herbigation of PE pendimethalin 1.0 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS. Among the herbigation treatments, herbigation of PE pendimethalin 1.0 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS obtained lower total weed density (12.13 m-2), total weed dry weight (9.19 g m-2) and higher WCE (86%) at 40 DAS. This was followed by herbigation of PE oxyfluorfen 0.2 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS. At 60 DAS, application of manual spray of PE pendimethalin 1.0 kg ha-1 + HW at 45 DAS recorded lower total weed density (18.07 m-2), total weed dry weight (16.03 g m-2) and higher weed control efficiency (85%). However, this was comparable with herbigation of PE pendimethalin 1.0 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS and HW on 20 and 40 DAS. The highest seed cotton yield (2109 kg ha-1) was obtained with manual spray of PE pendimethalin 1.0 kg ha-1 + HW at 45 DAS and it was on par with herbigation of PE pendimethalin 1.0 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS and HW on 20 and 40 DAS. Hence, considering the labour scarcity, herbigation of PE pendimethalin1.0 kg ha-1 on 3 DAS followed by manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS could be recommended for better weed control in drip irrigated cotton.