Vol. 11, Issue 4 (2022)

Author(s):
Amalesh Ghosh, Mahua Banerjee, GC Malik, Duvvada Sarath Kumar and Monotosh Das Bairagya

Abstract:
Rice (Oryza sativa L.) is a most important cereal crop grown in tropical and subtropical regions of the world and staple food for more than half of the world population. Generally, the yield reduction of rice due to weed growth may vary from 28-45% in transplanted rice. Hence, the field investigations were carried out at the agricultural farm of PSB (Institute of Agriculture) at Visva-Bharati, Sriniketan during wet seasons of 2014-15 and 2015-16 to study the integrated weed management in kharif rice (Oryza sativa L.) and its residual effect on succeeding Lathyrus (Lathyrus sativus). Experiments were tested in randomized block design replicated thrice. The experiment comprising of eleven treatments viz., T₁ - Mechanical weeding (25 DAT), T₂ - Bispyribac sodium 25g a.i ha^-1 (25 DAT), T₃ - Cyhalofop butyl 70 g a.i ha^-1 (25 DAT), T₄ - Pretilachlor 1.0 kg a.i ha^-1 (3 DAT), T₅ - Pretilachlor 1.0 kg a.i ha^-1 (3DAT) fb 1 Hand weeding (25 DAT), T₆ - Pretilachlor 1.0 kg a.i ha^-1 (3DAT) fb 1 Mechanical weeding (25 DAT), T₇ - Metsulfuron methyl fb Chlorimuron ethyl 4 g a.i ha^-1 (3DAT), T₈ - Metsulfuron methyl fb Chlorimuron ethyl 4 g a.i ha^-1 (3 DAT) fb 1 Hand weeding (25 DAT), T₉ - Metsulfuron methyl fb Chlorimuron ethyl 4 g a.i ha^-1 (3 DAT) fb 1 Mechanical weeding (25 DAT), T₁₀ - Weed free check and T₁₁- Weedy check. The highest grain yield was recorded under two hand weedings during both years as a result of reduced weed dry weight and increased growth attributes. This was at par with application of Metsulfuron methyl + Chlorimuron ethyl 4 g a.i ha^-1 (3 DAT) fb 1 Hand weeding (25 DAT). The results indicated that herbicides applied in rice did not show their residual effects on succeeding Lathyrus. Even though the results of two hand weedings were better, it cannot be recommended at larger scale as it is costly, time consuming and laborious. Hence, pre emergence application of Metsulfuron methyl + Chlorimuron ethyl 4 g a.i ha^-1 (3 DAT) fb 1 Hand weeding (25 DAT) can be recommended for better weed control and productivity in transplanted kharif rice.