Minimizing damage by Ditylenchus destructor to Peanut Seed with Early Harvest

Greenhouse and microplot experiments were conducted to evaluate the damage potential of Ditylenchus destructor on four South African commercial peanut cultivars as influenced by harvest date. The cultivars Sellie and Harts should be harvested by 150 and 120 days after planting, respectively. Losses were 12-13% with early harvest, but a 15-day delay resulted in losses of 45-49%. Harvest of Natal Common and Norden at 125 and 145 days after planting, respectively, resulted in the highest seed grade. By normal harvest time (140 and 160 days, respectively) these two cultivars were downgraded to crushing seed quality. Even though seed weight increases with time, a net loss occurs if harvest is delayed.     

Reproductive and Damage Potential of Ditylenchus destructor on Six Peanut Cultivars

Commercial peanut cultivars were evaluated for host suitability and sensitivity to Ditylenchus destructor. All cultivars were susceptible. Approximately 94% of the final population were in the pods. Highest Pf occurred at harvest on early maturing cultivars. Damage occurred on four of six cuttivars at Pi = 100/3 liters of soil and all six cultivars at Pi = 1,000. Norden and Selmani were the most susceptible cultivars. Sellie was the most tolerant and highest yielding cultivar. This cultivar may be the most profitable one for growers.