Yellow Nutsedge (Cyperus esculentus) Competition with Cotton (Gossypium hirsutum)

Abstract

Two series of experiments were conducted from 1976 through 1978 on Marvyn loamy sand in central Alabama to determine the competitive relationship of yellow nutsedge (Cyperus esculentusL.) with cotton (Gossypium hirustumL. ‘Stoneville 213’). In the first series of experiments yellow nutsedge was left undisturbed or removed from plots to give periods of competition of 0, 2, 4, 6, 8, 10, and 25 weeks. Seed cotton yield was reduced 2 of 3 yr with full season (25 week) competition, but was unaffected by shorter periods of competition in all years. Main stem diameter of cotton was also reduced 2 of 3 yr when competing full season while main stem height was reduced in only 1 of 3 yr with full season competition. In the second series of experiments yellow nutsedge densities were monitored in 48 individual plots and regression analysis showed yields of seed cotton were consistently reduced with full-season competition. Yellow nutsedge shoot densities ranged from zero to 93 shoots/m2(measured 13 cm on either side of the drill) and approximately 18 kg/ha of seed cotton were lost for each additional yellow nutsedge plant per m2.