Effect of integrated weed management on weed growth and yield of winter maize (Zea mays)

A field experiment was conducted during the winter (rabi) season of 2016 and 2017 at the Central Tobacco Re- search Institute, West Bengal. Treatments comprised 6 weed-management practices, viz. atrazine (1.5 kg/ha) + 2, 4-D (1 kg/ha) pendimethalin (1 kg/ha) + 2, 4-D (1 kg/ha), atrazine (1 kg/ha) + pendimethalin (kg a.i/ha) + 2, 4-D (1 kg/ha); atrazine (1.5 kg/ha) + 1 hand-weeding (HW), pendimethalin (1 kg/ha) + HW, atrazine (1 kg/ha) + pendimethalin (kg a.i/ha) + HW with weed-free check, and weedy checks with 4 replications in a randomized block design. The atrazine and pendimethalin were applied pre-emergence with tank mixed; 2, 4-D post-emergence at 30 days after sowing (30 DAS) and 1 hand-weeding at 30 DAS. The tank-mixed application of atrazine and pendimethalin followed by either post-emergence application of 2, 4-D at 30 DAS or 1 hand-weeding at 30 DAS significantly reduced the weed density by > 92% and weed dry weight by > 68% compared to weedy check. Maize yield attributes, grain yield and stover yield were significantly high in the weed-free check, at par with treat- ment of atrazine + pendimethalin + HW. The maximum yield loss was recorded in the weedy check by 66.55% and the minimum in atrazine + pendimethalin + HW, atrazine + pendimethalin + 2, 4-D. Treatment with atrazine + pendimethalin + 2, 4-D resulted in highest net returns ( 25,820) and benefit: cost (B:C ratio) of 0.54. The results clearly indicated that, the pre-emergence tank-mixed application of atrazine + pendimethalin followed by 1 hand- weeding at 30 DAS or the post-emergence application of 2, 4-D provided weed-free environment, and proved an effective integrated approach for weed management in winter (rabi) maize.