Intercropping of field crops in cotton for the management of purple nutsedge (Cyperus rotundus L.)

A 2-year field investigation was carried out during 2003–2004 to determine the effectiveness of intercropping single and double rows of sorghum, soybean and sesame in a cotton crop on the suppression of purple nutsedge (Cyperus rotundus L.). Results revealed that all three intercrops were effective in inhibiting purple nutsedge density (70–96%) and dry matter production (71–97%) during both years of experimentation. Control in the second year was more effective than in the first year. The seed cotton yield was also depressed by the intercrops but its suppression (8–23%) was far less severe than that of purple nutsedge and its loss was compensated by greater total economic returns. Intercropping of sorghum and sesame produced greater than 20% net benefits (up to 60%) in comparison with the control (cotton alone). Soybean intercropping produced comparable net benefits (95–103%). Sesame two rows intercrop treatment appeared the most profitable with net benefit of 51–59% with good purple nutsedge control (73–92% density suppression, 77–95% dry weight suppression) during both years of experimentation.