Crop Rotation and Herbicide Effects on Population Densities of Plant-Parasitic Nematodes


  • A. W. Johnson
  • C. C. Dowler
  • E. W. Hauser


The influence of herbicides and mono- and multicropping sequences on population densities of nematode species common in corn, cotton, peanut, and soybean fields in the southeastern United States was studied for 4 years. Each experimental plot was sampled at monthly intervals. The application of herbicides did not significantly affect nematode population densities. Meloidogyne incognita and Trichodorus christiei iucreased rapidly on corn and cotton, but were suppressed by peanut and soybean. More Pratylenchus spp. occurred on corn and soybean than on cotton and peanut. Criconemoides ornatus increased rapidly on corn and peanut, hut was suppressed by cotton and soybean. Helicotylenchus dihystera was more numerous on cotton and soybean than on corn and peanut. N umbers of Xiphinema americanum remained low on all crops. The peanut sequence was the most effective monocrop system for suppressing most nematode species. Multi-crop systems, corn-peanut-cotton-soybean and cotton-soybean-corn-peanut, were equally effective in suppressing nematode densities. Key Words: Zea mays, Gossypium hirsutum, Arachis hypogaea, Glycine max.