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.

Effects of Integrated Weed Management Practices on Weed Parameters and Yield of Bt Cotton (Gossypium hirsutum L.)

Aim: To know the effect of integrated weed management on weed parameters and yield of bt cotton.Study Design: Randomized complete block design.Place and Duration of Study: College of Agriculture Farm, Bheemaraynagudi between July 2021 and Feb 2022.Methodology: The field experiment was conducted during Kharif 2021 at Experimental block, College of Agriculture, Bheemarayanagudi. The soil of the experiment field was deep black clayey in texture. The experiment comprises 11 weed management practices viz., T1: Pendimethalin 38.7% CS @ 750 g a.i./ha as PE + Hand weeding @ 20-25 DAS and Intercultivation @ 55-60 DAS, T2: Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 75g a.i./ha + Quizalofop ethyl 5 EC @ 37.5g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS. (Tank mix), T3 : Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 50g a.i./ha + Quizalofop ethyl 5 EC @ 25 g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T4 :Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 75g a.i./ha + Quizalofop ethyl 5 EC @ 37.5g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T5 : Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 100g a.i./ha + Quizalofop ethyl 5 EC @ 50g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T6 : Pyrithiobac Sodium 10 EC @ 50g a.i./ha + Quizalofop ethyl 5 EC @ 25g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T7: Pyrithiobac Sodium 10 EC @ 75g a.i./ha + Quizalofop ethyl 5 EC @ 37.5g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T8: Pyrithiobac Sodium 10 EC @ 100g a.i./ha + Quizalofop ethyl 5 EC @ 50g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T9: Farmers practice (Hand weeding @ 25 DAS and 2 intercultivations @ 50 and 75 DAS), T10: Weedy check, T11: Weed free check.Results: Among the treatments, application of pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb pyrithiobac sodium 10 EC @ 100 g a.i./ha + quizalofop ethyl 5 EC @ 50 g a.i./ha as PoE (combi-product) @ 25 DAS and intercultivation @ 55-60 DAS recorded significantly lower weed density and higher weed control efficiency (82.39 %), also recorded higher seed cotton yield (2495 kg ha-1) and stalk yield (4056 kg ha-1) over other treatments.Conclusion: Application of Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 100g a.i./ha + Quizalofop ethyl 5 EC @ 50g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS was found effective in controlling the weeds with coupled with higher seed cotton yield .

Energy Balance Studies of Weed Management Practices in Mustard (Brassica juncea (L.) Czerj and Cosson)

An experiment was conducted at College Farm, College of Agriculture, Rajendranagar, Hyderabad during rabi 2020-21 on loamy sand soils to study energy balance of weed management practices in mustard. The energy balance studies were determined by using direct and indirect energy. Among the different weed management practices, Stomp 30 % EC as PE fb straw mulch 5 t ha-1 recorded higher energy input. This treatment was followed by Goal 23.5 % EC as PE fb straw mulch 5 t ha-1 and Raft 6 % EC as PE fb straw mulch 5 t ha-1. Maximum energy output, net energy, energy use efficiency and energy productivity were noticed under intercultivation and hand weeding at 15 and 30 DAS and it was statistically on par with Raft 6 % EC as PE fb intercultivation at 30 DAS, Goal 23.5 % EC as PE fb intercultivation at 30 DAS and Stomp 30 % EC as PE fb intercultivation at 30 DAS.