Effect of Defoliation on Peanut Plant Growth1

Defoliation experiments were performed in order to provide information for development of a pest management simulation model for peanuts (Arachis hypogaeaL.). ‘Florunner’ peanut plants were defoliated uniformly and nonuniformly at 9, 12, and 16 weeks after planting and harvested 2, 4, or 6 weeks following treatment. All defoliations resulted in lower stem weight to length ratios, lower pod numbers and weights, and equal or higher leaf numbers and weights. Defoliation altered the normal partitioning of photosynthate between plant parts. The location of defoliation damage (either uniform throughout the canopy or confined to the outer portion of the canopy) affected plant response in that plants defoliated nonuniformly grew more leaves in the 2 weeks following treatment than those defoliated uniformly