VIEW ARTICLE

Ecology and Epidemiology

Competitive Interaction of Tylenchorhynchus claytoni and Pratylenchus penetrans in Tobacco Roots. John L. McIntyre, Assistant Plant Pathologist, The Department of Plant Pathology and Botany, The Connecticut Agricultural Experiment Station, New Haven 06504; P. M. Miller, Plant Pathologist, The Department of Plant Pathology and Botany, The Connecticut Agricultural Experiment Station, New Haven 06504. Phytopathology 66:1427-1430. Accepted for publication 21 May 1976. Copyright © 1976 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-66-1427.

The numbers of Pratylenchus penetrans in roots of tobacco cultivar Windsor Shade 117 were reduced by prior or simultaneous exposure of roots to Tylenchorhynchus claytoni. Protection occurred both in naturally-infested soils and in sterile soils to which the nematodes were added. Protection against P. penetrans was not observed in control soils or if soils were first frozen to kill T. claytoni. The degree of protection depended on the concentration of T. claytoni. and ≥68 T. claytoni per 100 grams of soil provided nearly complete protection against P. penetrans. With a split-root system, there was protection to P. penetrans when one of the halves was exposed to T. claytoni and the other half was exposed simultaneously or sequentially to P. penetrans. Protection was not due to reduction in numbers of viable P. penetrans in roots and soil.