EFFECT OF WEED-CONTROL AND IRRIGATION REGIMES ON TRANSPLANTED RICE (ORYZA-SATIVA) IN KASHMIR VALLEY

A field experiment was conducted during rainy season of 1993 and 1994 on silty clay-loam soil of Shalimar in Kashmir to study the effect of weed-control practices and irrigation regimes on weed-control efficien cy and grain yield of transplanted rice (Oryza sativa L.); Among vario us weed-control treatments, weed-free treatment gave the highest weed- control efficiency and thereby resulted in the highest mean grain yiel d (6.32 tonnes/ha). It was 9.2, 70.8 and 77.5% more than that from the application of butachlor @ 1.5 kg a i/ha + 1 hand-weeding, 2,4-D (eth yl ester of 2, 4 dichlorophenoxy acetic acid) @ 1.0 kg ai/ha + I hand- weeding and unweeded control respectively. Weed-control efficiency and water-expense efficiency followed a trend identical to grain yield. H owever, application of butachlor @ 1.5 kg ai/ha + 1 hand-weeding prove d more profitable, with highest benefit : cost ratio (1.50). Different irrigation regimes did not cause variation in the dry weight of weeds and weed-control efficiency. However, delayed irrigation supressed th e broad-leaf weeds than continuous standing water (5 cm +/- irrigation at interval of 2 days). Continuous standing water and application of irrigation 2 days after infiltration of ponded water with mean benefit : cost ratio of 1.34 and 1.23 respectively recorded similar grain yie ld but significantly higher than irrigation at intervals of and 6 days , which in turn had higher mean water-expense efficiency.