Efficacy of low dose of herbicides against weeds in transplanted kharif rice (Oryza sativa L.).

Abstract

Comparative efficacy of penoxsulum 24 SC against weeds in transplanted kharif rice was studied at Regional Research Sub-Station (New Alluvial Zone), Bidhan Chandra Krishi Viswavidyalaya, Chakdaha, Nadia, West Bengal. The experiment was laid out in a randomized block design with 7 treatments and 3 replications. The results revealed that the major weed flora associated with the transplanted rice during kharif season was mainly comprised of Echinochloa colona (30 %), Cyperus difformis (20 %), Monochoria vaginalis (30 %) and Ludwigia parviflora (20 %). Penoxsulam 24 SC at 0.0225 kg a.i. ha-1 applied at 8-12 days after transplanting was most effective to check all types of weed population and their growth. This treatment also gave the maximum grain yield (3.53 tha-1) and straw yield (4.73 tha-1) of rice resulting in lowest weed index (5.61 %). Therefore, penoxsulam 24 SC at 0.0225 kg a.i. ha-1 applied at 8-12 days after transplanting may be recommended to replace the tedious, time consuming and expensive hand weeding practice of weed control in transplanted kharif rice.