Yellow Nutsedge (Cyperus esculentus) Interface in Peanut (Arachis hypogaea)

Abstract

Abstract Studies were conducted from 1997 to 1999 at the Coastal Plain Experiment Station in Tifton, GA to measure the full-season interference of yellow nutsedge in peanut using a response prediction experiment with a natural infestation of yellow nutsedge. Seeds of cultivar Georgia Green were planted in May each year, and plots were established immediately after crop emergence. Plots were 1.8 m by 1.8 m. with six replications. Yellow nutsedge plants were counted 28 d after crop emergence in each plot, and six weed-free plots were randomly established. Parameters measured were peanut yield and yellow nutsedge tuber contamination in harvested peanut. Yellow nutsedge densities ranged from 0 to 169 plants/m2. Regression analysis indicated a 25% reduction in peanut yield with a yellow nutsedge infestation of approximately 68 plants/m2. Each yellow nutsedge plant/m2 reduced peanut yield by 13 kg/ha. There was a positive linear response between yellow nutsedge density and number of tubers contaminating harvested peanut. Tuber contamination increased by 5190 tubers/ha for every yellow nutsedge plant/m2. The results indicated that yellow nutsedge is a poor competitor with peanut. However, tuber contamination in harvested peanuts should be considered when using these results in developing treatment thresholds.