EFFECT OF TIME AND METHOD OF ISOPROTURON APPLICATION ON WEEDS AND YIELD OF WHEAT (TRITICUM-AESTIVUM)

A 2-year field experiment conducted at New Delhi revealed that pendime thalin (pre-emergence) and isoproturon (WP) applied after first irriga tion were more effective against both grassy and broad-leaved weeds, w hereas 2,4-D and fluroxypyr only against broad-leaved weeds in wheat ( Triticum aestivum L. emend. Fiori & Paol.). Isoproturon (WP) mixed wit h urea and soil were less effective as compared to their spray applica tion. Hand-weeding resulted in higher grain yield in both the years, b ut was at par with pendimethalin and isoproturon (WP and its suspensio n) applied after irrigation in 1991-92, but proved superior to isoprot uron (suspension) in 1992-93. No significant difference was observed b etween pendimethalin and isoproturon (WP and suspension) when applied after first irrigation. Increase in grain yield was up to 18 and 12 q/ ha in 1991-92 and 1992-93 respectively.