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 kg/ha than all other treatments, except it was at par with pre-emergence application of thiozopyr at 0.48 kg/ha, atrazine at 2.0 kg/ha applied just after hoeing and 2 hoeings at 50 and 80 days after planting. Brachiaria mutica was completely controlled by the application of thiozopyr at all the rates. Pre-emergence application of metribuzin at 1 kg/ha, atrazine at 2.0 kg/ha alone or atrazine at 1.5 kg/ha and 2.0 kg/ha 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 treatments. Pre-emergence application of thiozopyr at 0.48 kg/ha gave significantly higher cane yield than its lower doses and was at par with thiozopyr at 0.36 kg/ha, metibuzin at 1.0 kg/ha and atrazine at 1.0 kg/ha just after hoeing. Atrazine at 1.5 kg/ha and 2.0 kg/ha applied after hoeing and 2 hoeings at 50 and 80 days after planting resulted in cane yield at par with weed-free condition.