Fungicide Performance for Management of Powdery Mildew on Lettuce in 2004

Abstract

Powdery mildew on lettuce is caused by the fungus Golovinomyces cichoracearum (Erysiphe cichoracearum). The disease is favored by moderate to warm temperatures and relatively dry weather conditions. Several fungicides were evaluated for their ability to suppress development of powdery mildew on lettuce in 2004. Powdery mildew appeared in our plots by January 15 and reached high levels by plant maturity (March 10). Compared to nontreated plants, all treatments significantly reduced the final severity of powdery mildew on lettuce. No powdery mildew was observed in plots treated with Cabrio, Quinoxyfen, Pristine, and Procure. High levels of disease suppression were evident in plots treated with Serenade+Sonata alternated with Quadris, Sonata, Actigard, Serenade+Sonata, and Quadris.