Weed Management Practices on Weed Characters, Plant Growth and Yield of Rice Under System of Rice Intensification

A field experiment was conducted during Kharif 2009 at Tamil Nadu Agricultural University, Coimbatore to evaluate weed management practices for System of Rice Intensification (SRI). The treatments comprised of different weed management practices viz., recommended weed management practice i.e. 4 times conoweeding from 10 DAT at 10 days interval and conoweeding 3 times at 20, 30 and 40 DAT. These two treatments in single and in combination with three different herbicides viz., almix @ 20 g a.i. ha-1, butachlor @ 1 kg a.i. ha-1 and pretilachlor @ 0.75 kg a.i. ha-1 were tested along with unweeded control treatment. The weed flora of the experimental field were Echinochloa crus-galli (L.), Cyperus difformis (L.), Eclipta alba (L.) and Ammania baccifera (L.). The results revealed that application of pretilachlor as PE @ 0.75 kg a.i. ha-1 + 4 times conoweeding from 10 DAT at 10 days interval (T5) was very effective in controlling the weeds and recorded the least weed density. The weed control efficiency (total and grassy weeds) as well as the plant growth components and yield were higher when rice was applied with Pretilachlor @ 0.75 kg a.i. ha-1 as pre-emergence + 4 times conoweeding from 10 DAT at 10 days interval, which was followed by the treatment of application of butachlor @ 1 kg a.i. ha-1 as pre-emergence + 4 times conoweeding from 10 DAT at 10 days interval.