Effect of weed management in productivity of Spring Maize in Mid-hills of Nepal

An experiment was conducted in IAAS, Lamjung research field in 2017 in spring Maize with split plot design to evaluate the effect of weed management practice and tillage system on productivity of spring maize. In tillage system, no-till and conventional tillage were kept as main factor whereas seven weed management practices (viz. sequential application of atrazine at 0.75 kg a.i. ha-1 and 2,4-D at 1.5 kg ha-1; pre-emergence tank mix application of atrazine at 0.75 kg ha-1 and glyphosate at 2.5ml lit-1 of water; pre-emergence tank mix application of atrazine at 0.75 kg ha-1 and pendimethalin at 2ml lit-1 of water; cowpea co-culture; black polythene mulch with control treatment weed free and weedy check as sub-plot. Tillage method had not significant effect on the weed dry matter accumulation in different stages. However, weed dry matter accumulation was varied with different weed management practices. The weed check plot was of highest dry matter accumulation (273.38g m-2, 361.95 g m-2 and 235.95 g m-2 in three different stages (30, 60 and 90 DAS respectively). The highest grain, straw yield and yield attributes was found in plastic mulch plot and no-till system with less severe to weed infestation and index which is statically at par with intercropping with cowpea. Though none of weed management practices completely eliminated weeds, black polythene mulching resulted in best grain yield. Besides the environmental protection, cowpea co-culture treatments yielded almost similar grain yield as compared with common herbicidal weed management practices.