Evaluating Weed Management Strategies and the Differential Effects of Herbicides on Weed Dynamics and Crop performance of Foxtail Millet Grown under the Irrigated Conditions of Rayalaseema

At the wetland farm of S.V. Agricultural College, Acharya N.G. Ranga Agricultural University, Tirupati, Andhra Pradesh, India, a field experiment was carried out during the (rainy season) kharif 2020 to evaluating weed management strategies and the differential effects of herbicides on weed dynamics and crop performance of foxtail millet [Setaria italica (L.) Beauv] grown under the irrigated conditions of Rayalaseema. The current study has shown that the application of pre-emergence pretilachlor 500 g ha-1 with intercultivation at 20 DAS was followed by hand weeding twice at 20 and 40 DAS and it led to the highest weed control efficiency, including foxtail millet's nutrient uptake, and the lowest weed density and dry weight. In unweeded check, a heavy weed infestation reduced the amount of nitrogen, phosphorus, and potassium absorbed by crop by 45.67, 18.03, and 35 kg ha-1, respectively. Crop growth parameters, straw and grain production was increased by hand weeding twice, however the benefit-cost ratio lagged behind the most effective weed management strategy, which is applying pre-emergence of pretilachlor 500 g ha-1with intercultivation at 20 DAS. The present experiment indicated that wherever the labour availability for hand weeding is abundant and cheaper, one can go for hand weeding or opt for the said herbicide recommendation taking into the economical considerations.

Effect of Pretilachlor 50% EC on Weed Control of Transplanted Rice under Alluvial Soil of West Bengal, India

Field experiments were conducted at Regional Research Station of Bidhan Chandra Krishi Viswavidyalaya, Gayeshpur, West Bengal during winter season of 2014 and 2015 to evaluate the bio-efficacy against weeds & phytotoxicity of pretilachlor 50% EC on transplanted rice. The experiment was tested under randomized complete block design with three replicates. Among the herbicides, highest weed control index was recorded in pretilachlor 50% EC @ 2 kg a.i. ha-1 which imparted phytotoxic symptoms in rice plants resulting in yield reduction. However, the highest grain yield (3.59 t ha-1) was obtained with the application of pretilachlor 50% EC @ 1.2 kg a.i. ha-1 which was statistically at par with twice hand weeding. From these findings it can be concluded that the application of pretilachlor 50% EC @ 1.2 kg a.i. ha-1 can be recommended for effective weed management in transplanted rice in the study area.