Competitive Effects between Purple Nutsedge (Cyperus rotundus Linn.) and Sugarcane

Abstract

The studies were conducted both in greenhouse and the sugarcanes field, in order to determine growth and yield of sugarcane when it was influenced with purple nutsedge (Cyperus rotundus L.) Obsevation in the dominated area of Rayong Chai-Nat and Suphan Buri found the population density of purple nutsedge shoot and tuber were 5,084,000 and 7,533,331 per hectare, respectively. Total dry weight of shoot and tuber was 14,700 kg/ha. Nitrogen at 250-312.5 kg/ha could induce growth of cane plants and provided more competitive ability with purple nutsedge. Entire season of purple nutsedge competition caused yield losses 60.6%. This study showed the critical period of this weed was during the first 4 months. The control was delayed to the second month caused more 30% of yield losses.