Weed control efficiency of bispyribac-sodium in transplanted and direct seeded rice and its residues in soil, rice grains and straw.

摘要

The efficacy of bispyribac-sodium, a new post-emergence broad spectrum herbicide was evaluated in transplanted rice (kharif of 2006 and 2007) and direct seeded rice (kharif of 2007) WCE of bispyribac against E. crus-galli when applied at 15 DAT was 67, 85, 88, 91 and 92% at 15, 20, 25, 30 and 60 g/ha during 2006 in transplanted rice while the corresponding figures during 2007 were 83, 92, 95, 100 and 85%, respectively. At 25 DAT, the dry weight of this weed 15, 20, 25, 30 and 60 g/ha reduced to the extent of 29, 88, 98, 98 and 100% during 2006 and 59, 81, 70, 92 and 99% during 2007, respectively. Control of E. crus-galli increased with the corresponding increase in the dose of bispyribac-Na from 20-30 g/ha and the maximum WCE was attained at 30 g/ha in direct seeded rice. HPLC analysis indicated that there were no residues of this herbicide in soil, rice grains and straw at crop harvest in transplanted and direct seeded rice.