Weed growth and productivity of summer greengram (Vigna radiata L.) under sole and sequential application of herbicides

Abstract

Greengram is a short stature crop, whose growth is sluggish during the early period which makes it susceptible to very intense weed competition from a divers weed flora. An investigation was carried out during the summer season, 2021 at Agricultural Research Station, Binjhagiri, Siksha ‘O’ Anusandhan, deemed to be University, Bhubaneswar, India to evaluate the efficacy of sole and sequential application of herbicides on weed growth, productivity and profitability of summer greengram. Ten treatments comprise of sole and sequential application of pendimethalin, imazethapyr at different doses, two hand weeding and weedy check were replicated thrice in the randomized block design. The major weed flora found in the experimental area were Poa annua, Digitaria sanguinalis, Melochia corchorifolia, Aeschynomene afraspera and Grangea maderaspatana. Study revealed that among the herbicidal treatments, application of pendimethalin @ 1000 g/ha at 1 day after sowing (DAS) fb imazethapyr @ 75 g/ha at 20 DAS registered significantly the minimum weed density and biomass along with higher values of weed control efficiency, which was statistically at par with pendimethalin @ 750 g/ha at 1 DAS fb imazethapyr @ 75 g/ha at 20 DAS treatment. The highest productivity (8.16 q/ha) was significantly recorded under twice hand weeding at 15 and 35 DAS, which was found to maintain statistically similar yield levels with pendimethalin @ 1000 g/ha at 1 DAS fb imazethapyr @ 75 g/ha at 20 DAS (8.05 q seed/ha) and pendimethalin @ 750 g/ha at 1 DAS fb imazethapyr @ 75 g/ha at 20 DAS (7.97 q seed/ha). However, the sequential application of pendimethalin @ 750 g/ha at 1 DAS fb imazethapyr @ 75 g/ha at 20 DAS revealed the highest B:C ratio (1.93) in terms of profitability of greengram. Thus, sequential application of pendimethalin @ 750 g/ha at 1 DAS fb imazethapyr @ 75 g/ha at 20 DAS appeared to be promising for effective weed management, higher productivity and profitability in summer greengram.