Control of Meloidogyne chitwoodi in Commercially Grown Russet Burbank Potatoes. J. N. Pinkerton, Research Associate Nematologist, Washington State University, Irrigated Agriculture Research and Extension Center, Prosser 99350. G. S. Santo, Associate Professor, Nematology, R. P. Ponti, Agricultural Research Technologist I, and J. H. Wilson, Agricultural Research Technologist III, Washington State University, Irrigated Agriculture Research and Extension Center, Prosser 99350. Plant Dis. 70:860-863. Accepted for publication 3 February 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-860.

Efficacy of fumigant and nonfumigant nematicides alone and in combination for control of the Columbia root-knot nematode (Meloidogyne chitwoodi) was studied in a commercial Russet Burbank potato field. The soil-injected fumigant dichloropropene in combination with preplant ethoprop treatments significantly (P = 0.05) reduced tuber infection to commercially acceptable levels (≤3% nematode culls). The dichloropropene-aldicarb combination and sprinkler-irrigation-applied metam-sodium significantly reduced tuber infection, although percent culls was ≥10. Single ethoprop, multiple ethoprop, and ethoprop-aldicarb combination treatments were less effective, with ≥19% culls. Aldicarb alone and dichloropropene alone provided no significant (P=0.05) nematode control, with ≥84% culls. All treatments except sidedress aldicarb significantly increased total yield and estimated dollar return.