Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 14, 1999
Publication Date: December 17, 1999
Citation: Johnson, W.C. 1999. Interference and economic threshold of yellow nutsedge with peanut. American Peanut Research and Education Society Abstracts. 31:29. Technical Abstract: Studies were conducted in 1997 and 1998 at the Coastal Plain Experiment Station in Tifton, GA to measure the effects of full-season interference of yellow nutsedge on peanut using a response prediction experiment with a natural infestation of yellow nutsedge. 'Georgia Green' peanut was seeded in May each year, and plots were established immediately after seedling emergence. Plots were 1.8 m by 1.8 m replicated six times. Yellow nutsedge plants were counted four weeks after peanut seedling emergence in each plot, at which time six weed-free plots were randomly established. Parameters measured were number of yellow nutsedge tubers and foreign material in harvested peanut and yield. All parameters were regressed against yellow nutsedge density, which ranged from 0 to 127 plants/m2. Regression analysis showed a 5% reduction in peanut yield with a yellow nutsedge infestation of approximately 6 plants/m2 (R2 = 0.50). Each yellow wnutsedge plant/m2 reduced peanut yield by 59 kg/ha. Data also showed a linear response between yellow nutsedge density and number of tubers contaminating harvested peanut. Tuber contamination increased by 5% for each yellow nutsedge plant/m2. These results indicated that yellow nutsedge is an effective full-season competitor with peanut in the absence of any control efforts. However, given the documented susceptibility of yellow nutsedge to shading from other plants, early season control efforts in peanut should minimize losses.