EFFECT OF ROW SPACING, MULCHING AND WEED-CONTROL ON WEED GROWTH AND YIELD OF SOYBEAN (GLYCINE-MAX)

A field study carried out during time rainy season of 1992 and 1993 re vealed that reduction in row spacing from 45 cm to 25 cm increased til e weed-control efficiency by 21.7% and grain yield by 15.6%. The oil c ontent was also increased but protein content decreased, Though mulchi ng at 5 tonnes/ha was effective ill controlling weeds (23%) and increa sing grain yield (9.3%), it was found uneconomical. Weed control throu gh maintenance of weed-free conditions up to 75 days after sowing or a pplication of fluchloralin at 1.5 kg/ha preplanting incorporation + in terculturing at 40 days after sowing were equally effective. However, the latter was economically more viable. Combined application of all t he above treatments were found beneficial than their singe use.