Evaluation of Alternate Tillage and Weed Management Options on Production Potential and Weed Incidences for Dry Seeded Rice (DSR)

Abstract

The study which aims at the evaluation of conservation tillage and to identify appropriate management options for dry seeded rice (DSR) under conservation tillage system was carried out at the Bangladesh Rice Research Institute (BRRI), Regional station, Rajshahi during wet season of 2010 and 2011. The experiment was laid out in split plot design with three replications. The main plot treatments were Zero tillage (ZT), Strip tillage (ST) using power tiller operated seeder (PTOS), Minimum tillage using PTOS (MT), Permanent bed (PB) using bed planter, Fresh bed (FB) using bed planter and Conventional tillage (CT). Except conventional tillage, other alternate tillage treatments considered as conservation tillage treatments. The subplot treatments were Weed free (W1); Post emergence herbicide + 1 hand weeding (W2), Pre-emergence herbicide + post-emergence herbicide (W3), Post emergence herbicide alone (W4) and Weedy control (W5). Pandimethylin and Bispyribac Sodium were the pre and post emergence herbicide, respectively. Among the tillage treatments, conventional tillage (CT) registered comparatively lower weeds population as well as weeds biomass. Alternate tillage treatments showed about similar result in terms of weed incidences. Again, crop weed competition almost remained same among the weed free and herbicide applied treatments. Although the number of panicle m-2 was comparatively lower, the higher panicle length associated with higher grains panicle-1 was achieved in fresh bed and permanent bed treatments. The grain yield of rice was also comparable among the conventional tillage, bed planting system and also the zero or strip tillage treatments. On the other-hand, the post emergence herbicide W4 treatment (Bispyribac Na+) was found more effective in controlling weeds where W1 (weed free) and W2 treatment (Bispyribac Na+) + 1 hand weeding) showed identical effect in relation to weed intensity, grain and straw yield of rice.