1University of Agricultural Sciences, Regional Research Station, V.C. Farm, Mandya
*Presented at the Indian Society of Weed Science 1980 Conference held at Bhubaneswar from July 21–23, 1980. Agronomist, Agricultural Research Stataion, Dharwar Farm, Dharwar, Karnataka.
In red sandy loams of South-Karnataka dicot weeds are more problematic than monocots in sugarcane. of the six weedicides tested under field conditions for a period of 3 years (1976–77, 1977–78 and 1978–79), Metribuzin was found to be more effective in controlling all types of weeds. At months after planting sugarcane, dicot weed population was 2–3 in one M2 area when metribuzin was sprayed only once at 1 kg/ha. as pre-emergent spray. While at higher concentration of 2 kg/ha-half as pre-emergencs and remaining half as post emergence spray, dicot weed population was 0–1/M2 area. In no chemical weedicide spray the weed population ranged from 86 to 194/M2. Weed population continued to be at low even up to 5i months after planting. Higher dose of weedicide was toxic to the crop resulting in lower cane yield by 10 to 15 tons/ha, over lower dose during 2 years while during one year (1977–78) there was increase in cane yield by 34 tons/ha, when weed population was more. With proper weed control in different weedicides, there was significant improvement in number of tillers per shoot and millable canes at harvest.
