Herbicidal management in monsoon green gram (Vigna radiata (L.) Wilczek) and its effect on the following rapeseed (Brassica campestris L. var. Yellow Sarson) in the Indo-Gangetic plains of Eastern India

Abstract

Abstract Weeds, if not timely controlled, severely limit productivity of short-duration monsoon green gram. The aim of the present study was to identify a sustainable herbicidal management strategy in green gram-rapeseed rotation. Efficiency, phytotoxic effects in greengram and follow-up crop (rapeseed), yield, and economics of pre-emergence Pendimethalin and Pendimethalin + Imazethapyr and post-emergence [20 days after sowing (DAS)] Imazethapyr, Imazamox + Imazethapyr, and Acifluorfen sodium + Clodinafop propargyl were compared. Ready-mixes of two herbicide molecules were used. Among the herbicides, green gram treated with Imazamox + Imazethapyr (60 g a.i. ha−1) and Acifluorfen sodium + Clodinafop propargyl (187.5 g a.i. ha−1) showed significantly higher weed control efficiency of 81.3–85.1% and 90.5–92.9% on 30 and 55 DAS, respectively. In spite of initial herbicide induced oxidative stress and phytotoxicity, the crop treated with above-mentioned ready-mixes resumed normal growth within 15 days of herbicide application. They also recorded improvement in yields and net returns by 44.0–47.2% and 145.0–153.0%, respectively over weedy check. Detrimental residual effects on germination and yield were not observed in following rapeseed crop. These herbicide ready-mixes may be a promising weed management strategy for the monsoon green gram grown in the uplands of rice-dominated Indo-Gangetic plains.