Control of Stubby-Root Nematodes in Onions with Oxamyl. H. J. Jensen, Professor of Nematology, Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331. J. N. Pinkerton, Research Assistant in Nematology, Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331, and T. E. Nishimura, Biochemicals Department, E. I. du Pont de Nemours & Company, Menlo Park, CA 94025. Plant Dis. 67:43-44. Accepted for publication 17 May 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-43.

Severe stunting and reduction of the root system by Paratrichodorus allius resulted in a significant yield reduction of dry onion production. Several combinations of rates, methods, and treatment dates with oxamyl were evaluated as control alternatives. Fifteen of 20 treatments resulted in higher (P = 0.05) yields than untreated controls. A granular formulation of 3.36 kg a.i./ha applied in the furrow at planting was the best treatment; however, because this formulation may not be readily available, growers have a choice of several other treatments that provide excellent yields.