Chemical Control of Selected Plant-Parasitic Nematodes in Soybeans Double-Cropped with Wheat in No-Till and Conventional Tillage Systems. D. P. Schmitt, Associate Professor, Department of Plant Pathology, P.O. Box 7616, North Carolina State University, Raleigh 27695-7616. L. A. Nelson, Professor, Department of Statistics, P.O. Box 8203, North Carolina State University, Raleigh 27695-8203. Plant Dis. 71:323-326. Accepted for publication 3 November 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0323.

Efficacy of aldicarb, ethylene dibromide (EDB), and fenamiphos for control of selected plant-parasitic nematodes, with emphasis on Heterodera glycines, was determined in no-till- and conventional tillage-planted soybeans. Greatest numbers of H. glycines eggs recovered 2 mo after planting were in conventionally tilled plots. Populations of Tylenchorhynchus claytoni were lowest in in-row subsoiled, no-till treatments and highest in no-till, nonsubsoiled treatments. Nematicide effects were not consistent across years as measured by population densities. Profitable yields every year were achieved only in in-row subsoiled, no-till plots treated with EDB. The nonfumigant nematicides may not give enough economic benefits to justify their use on soybeans grown after small grains in H. glycines-infested fields.

Keyword(s): Glycine max.