Effect of Fungicides Applied at Different Rates on Control of Sclerotinia Leaf Drop of Lettuce -- 1990 Field Test

Leaf drop of lettuce, caused by the plant pathogenic fungi Sclerotinia sclerotiorum and S. minor, is found every year in some lettuce fields in Arizona. When environmental conditions are favorable, disease incidence and resulting crop loss can be significant. During the 1989 -90 lettuce season in western Arizona, different fungicides and rates of materials were evaluated in the field for disease control Ronilan and Rovral, the two fungicides currently registered for use on lettuce for control of Sclerotinia leaf drop, provided significant disease suppression and increased yields at all rates tested. Bravo and Botran did not control the disease