Studies on integrated weed management practices in spring planted sugarcane of coastal Orissa.
The efficacy of integrated weed management practices in spring-planted sugarcane was evaluated during 1999 and 2000 in Nayagarh, Orissa, India. Pre-emergence herbicides atrazine at 2.0 kg, metribuzin at 1.0 kg, pendimethalin at 1.0 kg and ametryn at 2.0 kg were applied at optimum soil moisture condition. Post-emergence application of herbicides 2,4-D at 1.0 kg and glyphosate at 1.01 kg/ha, and manual hoeing were performed as per treatment specifications. The dominant weed flora of the experimental site consisted of Cyperus rotundus, Cynodon dactylon, Digitaria sanguinalis, Mimusops pudica, Echinochloa colona, Solanum nigrum, Tridax procumbens and Ipomoea sp. Pre-emergence application of ametryn with one hoeing at 60 days after planting (DAP) recorded lower weed flora and dry weight and higher average cane yield of 149.8 tonnes/ha compared with the weedy control (103.4 tonnes/ha). The next best treatment was 3 manual hoeings at 30, 60 and 90 DAP, recording high yield of 146.2 tonnes/ha. The highest net return (Rs 67 550) and benefit:cost ratio (1.51) were also obtained from pre-emergence application of ametryn+one hoeing at 60 DAP.