Evaluation of mulching, intercropping with Sesbania and herbicide use for weed management in dry-seeded rice (Oryza sativa L.)

This study was conducted to evaluate the effects of intercropping Sesbania with dry-seeded rice up to its vegetative phase (Sesbania), mulching with wheat residue (mulch) and herbicides for managing weeds and optimising the yield of dry-seeded rice. The density of grass weeds was lower with the mulch at all stages of crop growth. Though the dry weight of grass weeds at 30 days after seeding (DAS) was lower with Sesbania than with mulch, they were similar at later stages. A lower broadleaved weed density and dry weight were observed with Sesbania than with the mulch. It is concluded that application of wheat residue mulch at 4 t ha(-1) and Sesbania intercropping for 30 days were equally effective in controlling weeds associated with dry-seeded rice. However, pendimethalin (1000 g a.i. ha(-1)) or pretilachlor with safener (500 g a.i. ha(-1)) as pre-emergence applications followed by one hand-weeding were effective in controlling weeds, increasing grain yield of dry-seeded rice, and resulting in higher net returns than the weed-free treatment. (c) 2006 Elsevier Ltd. All rights reserved.