Effects of Soil Fumigation, Rotation, and Nitrogen on Yield, Petiole NO3-N, and Verticillium Wilt of Potatoes1

Abstract

Abstract The effects of soil fumigation with Telone C-17 on yield, petiole NO3-N levels and verticillium wilt (incited by Verticillium albo-atrum Reinke & Berth and V. dahliae Kleb.) of potatoes (Solanum tuberosum L.) grown continuously and in a 2-year rotation with corn since 1972 at 8 rates of nitrogen were studied in 1978 and 1979. Soil fumigation resulted in significant yield increases where potatoes were grown continuously. Potatoes grown in rotation responded to fumigation only in 1979. Continuous culture of potatoes resulted in reduced yields in both years. Nitrate-N levels were substantially lower in petioles from fumigated plots than in non-fumigated plots. Yield responses from fumigation and rotation were the result of reduced severity of verticillium wilt infestation. Soil fumigation and rotation had equal effects on yield and verticillium wilt, particularly in 1979.