Weed management in groundnut under rice-fallow

A field experiment was conducted at Agricultural Research Station, Utukur, Kadapa, Andhra Pradesh, India during Rabi seasons of 2016 and 2017 to test the efficacy of herbicides in rice-fallow groundnut. It is common that previous rice volunteer plants will come in the succeeding crops after rice. Keeping all this in view, the experiment was conducted with six weed control treatments arranged in a randomized block design (RBD) with four replications. Preemergence application of pendimethalin 1.5 kg/ha followed by post-emergence application of imazethapyr 75 g/ha at 18–20 DAS recorded lower density of both broad-leaved and grassy-weeds. Weed free throughout the crop period recorded higher pod yield (4.24 t/ha), which was at par with hand weeding twice at 20 and 40 DAS (4.19t/ha) and pendimethalin 1.5 kg/ha as pre-emergence followed by imazethapyr 75 g/ha as post-emergence at 18–20 DAS (3.91 t/ha). Higher benefit: cost ratio (2.20) was recorded with pre-emergence application of pendimethalin 1.5 kg/ha followed by post-emergence application of imazethapyr 75 g/ha at 18–20 DAS.