Chemical weed control in wheat (Triticum aestivum) and its residual effects on greengram (Vigna radiata)

A field experiment was conducted from winter (rabi) 2013–14 to rainy season (kharif) 2015 on sandy-loam soil, to assess the comparative efficacy of different chemical herbicides and their combinations for effective weed control in wheat (Triticum aestivum L.) and their residual effect on succeeding greengram Vigna radiate (L.) R. Wilczek crop at Instructional Farm, Sumerpur, Rajasthan. The experiment comprised 9 treatments and the herbicides were applied at 30–35 days after sowing (DAS) as prescribed. The application of sulfosulfuron + metsulfuron methyl @ 32 g/ha recorded significantly lower weed dry matter and weed index along with highest weed-control index (76.73 %). This herbicides combination also resulted in the highest grain yield of wheat (3.82 t/ha) along with highest net return and maximum benefit to cost ratio of the system in the tune of 3.4 : 1 as compared to weedy check. The herbicides failed to influence a significant increase on seed yield of succeeding greengram during kharif seasons in both years. Uncontrolled weed growth throughout the crop growth period caused an average yield reduction of 57% in wheat crop (2.5 t/ha).