EVALUATION OF POTENTIAL SUPPRESSION OF POWDERY MILDEW ON CORNUS FLORIDA WITH FOLIAR APPLICATIONS OF COMPOST TEA AND SURFACTANTS

Abstract

Compost tea is mature compost steeped in water to produce liquid extract that may provide control of fungal pathogens that is safer and cheaper than chemical pesticides. There is much research on compost tea but results have been inconsistent and confirmation of effects is needed. This study was designed to evaluate the efficacy of compost tea for preventing and suppressing powdery mildew, Microsphaera pulchra on flowering dogwood, Cornus florida. Leafgro, a local compost product with consistent parent material, was tested as foliar spray. Results showed significant disease suppression in compost tea applications compared to control with as much as 85% less disease. Two organic surfactants, Nu-Film P and Vapor Gard, also showed significant suppression with up to 100% disease prevention. Application intervals were also assessed for potential spray programs. Overall, compost tea and surfactants showed potential as fungicides but further study is needed to verify results in this experiment.