Decrease in Incidence of Rhizoctonia Preemergence Damping-Off by Use of Integrated Chemical and Biological Controls. Ran Lifshitz, Visiting Scientist, Plant Pathology and Weed Science, Colorado State University, Fort Collins 80523. Sarit Lifshitz, Research Associate, and Ralph Baker, Professor, Plant Pathology and Weed Science, Colorado State University, Fort Collins 80523. Plant Dis. 69:431-434. Accepted for publication 19 November 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-431.

The ED₅₀ value for control of Rhizoctonia preemergence damping-off of radish by benodanil was 1.3 μg a.i./g of soil. Seed treatment with conidial suspensions of Trichoderma harzianum was effective in reducing incidence of damping-off. Mixing conidia of the antagonist in soil did not control the disease. Incidence of damping-off decreased in the latter treatment in subsequent weekly replantings of radish until emergence was not significantly different from that in the uninoculated control. Control of damping-off by both seed treatment with T. harzianum and soil mix of benodanil was additive but not interactive. Integration of chemical and biological controls provides opportunities for enhancement and greater efficiencies in suppressing damping-off induced by Rhizoctonia solani.