Evaluation of biological control agents for control of botrytis blight of geranium and powdery mildew of rose.

摘要

Four commercially formulated biological control products, containing Gliocladium catenulatum (PrestopReg. WP), Trichoderma harzianum (PlantShieldReg.) and Bacillus subtilis [SerenadeReg. MAXTM (wettable powder) and RhapsodyReg. ASOTM (liquid)] were evaluated for control of rose powdery mildew (Podosphaera pannosa) on outdoor, container-grown roses and botrytis blight (Botrytis cinerea) on greenhouse-grown zonal geraniums in 2006 and 2007. The products were applied every 7-14 days and disease incidence and severity were compared to the fungicides captan for botrytis blight control and myclobutanil for powdery mildew control. Gliocladium catenulatum provided the best control of botrytis blight of geranium in both years, and disease incidence was significantly lower compared with plants treated with captan. Both G. catenulatum and B. subtilis (Serenade MAXTM applied every 14 days or Rhapsody ASOTM every 7 days) provided significant control of rose powdery mildew, which was comparable to that provided by myclobutanil. These preventative disease-suppressive biological control products may have a useful role in commercial nursery crop production.