Evaluation of Fungicides for Control of Powdery Mildew of Greenhouse Pepper

A fungicide trial was established in a commercial style greenhouse at The University of Arizona Campus Agricultural Center in November 2000 to evaluate efficacy of several fungicides for control of powdery mildew on bell pepper. Treatments included five registered fungicides: Microthiol Special (micronized sulfur), Trilogy (neem extract), Flint (trifloxystrobin), Serenade (Bacillus subtilis QST713) and AQ10 (Ampelomyces quisqualis) applied as single treatments every 10-14 days to each of four replicates. In samples to determine the percentage of leaf area affected by powdery mildew lesions and the number of leaves infected within different treatments, Microthiol Special and Serenade were significantly different from non-treated controls, while Flint and AQ10 had fewer lesions and number of leaves infected but were not significantly different from the control. Although Trilogy was not different from the control, this treatment had more lesions and number of leaves infected than all treatments