HALOSULFURON FOR SELECTIVE CONTROL OF PURPLE NUTSEDGE IN MAIZE

Ten field trials were conducted in the Waikato and Bay of Plenty between 1995 and 1997 to evaluate the effectiveness of post-emergence halosulfuron for control of purple nutsedge (Cyperus rotundus) in maize. Halosulfuron severely damaged the foliage of purple nutsedge and reduced its population and ground cover at rates between 32.5 and 130 g/ha. Repeat annual applications of halosulfuron were necessary to reduce the number of tubers to low levels. Halosulfuron caused chlorosis and some stunting of young maize plants but they grew out of the damage and neither grain yields nor crop maturity were affected. Crop tolerance was similar following prior use of any of the currently registered pre-emergence herbicides for maize.