Department of Forestry, J. N. K. V. V., Jabalpur - 482 004 (M. P.), India.
Field experiments were carried out on transplanted rice cv. Kranti during kharif 1988 and 1989 at Jabaipur (M. P.) to find out the suitable planting geometry, weed management and nitrogen requirement for improving the weed control efficiency (WCE), yields and profits. The square planting pattern (15 x 15 cm) significantly reduced the dry weight of weeds and had higher WCE than rectangular planting (22.5x10cm). It provided higher yields and income over rectangular planting. Both, manual (hand weeding twice at 25 and 45 DAT) and chemical (application of butachlor, 1.5kg/ha at 7 DAT + propanit, 2kg/ha at 30DAT), weed control practices were equally good with regard to WCE, yields and profits. They proved significantly superior over unweeded check. The weed biomass, crop yield and profit increased linearly with increase in the rate of nitrogen application upto 120 kg N/ha, but the benefit: cost ratio did not increase significantly beyond 80 kg N/ha.