Crop-weed competition, Sorghum, Weed management

A field experiment was conducted at Instructional Farm, Navsari Agricultural University, Navsari during 2013-14 and 2014-15 with a view to study the crop-weed competition as influenced by different weed management practices in Rabi (winter season) sorghum (Sorghum bicolor L.). Twelve weed management treatments were evaluated in a randomized block design with four replications. Pre-emergence (PE) application of atrazine 0.5 kg/ha + pendimethalin 0.25 kg/ha as tank mixture significantly reduced weed population and weed biomass, increased the weed control efficiency at early stage, next to weed free treatment. However, at the rest of the growth stages, two HW and inter culturing (IC) at 20 and 40 DAS, atrazine 0.5 kg/ha PE + HW and IC at 20 DAS, pendimethalin 0.5 kg/ha PE + HW and IC at 20 DAS effectively controlled the weeds, reduced the weed biomass and increased the weed control efficiency. Nutrient losses by weeds were highest under unweeded control and lowest with weed free condition followed by application of atrazine 0.5 kg/ha PE + HW and IC at 20 DAS.