Abstract
Field trials were conducted to determine the effect of yellow and purple nutsedge (Cyperus esculentum L. and C. rotundus L.) time of emergence on the area of influence of each weed on bell pepper (Capsicum annuum L.). A single weed was transplanted 1, 2, 3, 4, and 5 weeks after bell pepper transplanting (WAT) and bell pepper yield was collected at 0, 30, 60, and 90 cm from each weed. Bell pepper yield data indicated that yellow nutsedge was more aggressive than purple nutsedge interfering with bell pepper. When yellow nutsedge emerged 1 WAT, bell pepper yield losses were between 57 and 32% for plants at 0 and 30 cm away from the weed, respectively, which represents at least a density of approximately 3.5 plants/m. For purple nutsedge, one weed growing since 1 WAT between two bell pepper plants (0 cm; 10 plants/m) produced a yield reduction of 31%. These results indicated that low nutsedge densities, which are commonly believed to be unimportant, can cause significant bell pepper yield reductions.
