EVALUATION OF EFFICACY OF CHEMICAL AND BIOLOGICAL FUNGICIDES FOR CONTROL OF RHIZOCTONIA ROOT ROT IN BEDDING PLANTS

The efficacy of chemical fungicides - Abound, Banrot, and ZeroTol, and biocontrol agents - PlantShield and SoilGard, were evaluated to control Rhizoctonia root rot of bedding plants in a retractable roof greenhouse. The pathogen lacked virulence and resulted in up to 7% mortality in control treatments. Comparatively, petunia white had a greater mortality than other cultivars. Survival of Abound treated plants was 100% for all four experiments. Often, dry weight and quality of plants of all treatments were not significantly different from inoculated and untreated control plants. ZeroTol applied at the highest recommended rate (20 ml L-1 of water) caused phytotoxicity to cool season plants reducing dry weight up to 64% in petunia red. The effectiveness of conventional fungicides and biocontrol agents to control Rhizoctonia root rot in bedding plant production and simulated landscape conditions cannot be evaluated from the results of this study because of low disease severity