Effect of weed-management practices on spring-planted sugarcane

A field experiment was conducted during 1997-98 and 1998-99 to study the effect of weed-management practices on spring-planted sugarcane and associated weeds. Significantly lower density of Echinochloa spp. was recorded with the pre-emergence application of thiozopyr at 0.36 kglha than all other treatments, except it was at par with pre-emergence application of thiozopyr at 0.48 kglha, atrazine at 2.0 kglha applied just after hoe- ing and 2 hoeings at 50 and 80 days after planting. Brachiaria mutica was completely controlled by the applica- tion of thiozopyr at all the rates. Pre-emergence application of metribuzin at 1 kglha, atrazine at 2.0 kglha alone or atrazine at 1.5 kglha and 2.0 kglha just after hoeing caused complete control of Parthenium hysterophorus. Uncontrolled weeds on an average caused 65.3% reduction in the cane yield compared to weed-free treat- ments. Pre-emergence application of thiozopyr at 0.48 kglha gave significantly higher cane yield than its lower doses and was at par with thiozopyr at 0.36 kglha, metibuzin at 1.0 kglha and atrazine at 1.0 kglha just after hoe- ing. Atrazine at 1.5 kglha and 2.0 kglha applied after hoeing and 2 hoeings at 50 and 80 days after planting re- sulted in cane yield at par with weed-free condition.