Effect of Crop Rotation on Soybean in a Field Infested with Meloidogyne arenaria and Heterodera glycines.

Previous cropping sequence (corn-soybean vs. soybean-soybean) and aldicarb effects on soybean yield and nematode numbers at harvest for soybean cultivars with various combinations of nematode resistance were determined in 1988 in a sandy loam soil infested with Meloidogyne arenaria race 2 and Heterodera glycines races 3 and 4 at Elberta, Alabama. Yield and nematode numbers differed among cultivars with 'Leflore' having the highest yield. Aldicarb treatment resulted in increased soybean yield but did not affect nematode numbers. Previous cropping sequence did not affect soybean yield or numbers of H. glycines, but soybean following corn-soybean had higher numbers of M. arenaria than soybean following soybean-soybean. The only significant statistical interaction was aldicarb x cultivar for numbers of H. glycines.