Decrease in Incidence of Rhizoctonia Preemergence Damping-Off by Use of Integrated Chemical and Biological Controls

Abstract

The ED50 value for control of Rhizoctonia preemergence damping-off of radish by benodanil was 1.3 .mu.g a.i./g [active ingredient] 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.