Effect of different weed management practices on weed dynamic, yield and economics of soybean production

A field experiment was conducted to study the effect of different weed management practices on weed dynamics, yield and economics of soybean (Glycine max L.var. JS-335) production. Experiment was carried out in randomized block design consisting of thirteen weed management practices replicated thrice (pre-emergence and post- emergence application of herbicides, cultural and mechanical weed management practices). Experimental field was mostly dominated by grassy weeds namely; Sorghum halepense, Cynodon dactylon, Digitaria sanguinallis with broad leaf weeds and sedges. Total weed population and weed dry matter production was significantly highest in weedy check plot. Two hand weeding at 20 and 40 Days after sowing (DAS) with highest weed control efficiency (84.29 %) recorded lowest weed population and weed dry matter accumulation with highest values of growth and yield attributes, seed and stalk yield. Pre-emergence (PE) application of pendimethalin 1.0 kg ha-1 supplemented by hand weeding at 40 DAS was next best treatment to record lower weed population, weed dry matter accumulation and higher seed yield with the weed control efficiency of 80.83 %. Pendimethalin 1.0 kg ha-1 as pre-emergence followed by (fb) quizalofop-p-ethyl 50 g ha-1 at 20 DAS highly efficient for dominating grassy weed; Sorghum halepense produced comparable seed and stalk yield with lower cost of cultivation and recorded highest net return (711.22 $ ha-1) and benefit: cost ratio (1.51) over all other treatments with mean that 1 $ investment can fetch 1.51 $ net return thus proving more economical and profitable weed management practice among all treatments.