Four summer cropping practices (sorghum cover crop, weed cover, chemical fallow, or mechanical fallow) had no influence on total tuber weights of a subsequent winter potato crop, despite reduction of certain plant-parasitic nematode species by some systems. Marketable yields were significantly affected, however, since wireworm damage to tubers was increased following non-fallow treatments compared with fallow treatments, and was greatest following sorghum cropping. In two subsequent experiments, maintenance of various intervals of sorghum cover and clean fallow had minimal effect on soil fertility and nematode populations, and did not effect total potato yields. In both experiments, wireworm damage to tubers showed significant linear and quadratic relationships to the number of days a sorghum cover crop had been present.
