Sclerotinia Leaf Drop of Lettuce - Testing New Fungicides and Formulations of Ronilan for Disease Control

Abstract

Leaf drop of lettuce, caused by the fungus Sclerotinia sclerotionunb is a sporadic but potentially destructive disease in Arizona During the 1988-89 lettuce season in western Arizona, different fungicides and formulations of materials were evaluated in the field for disease control. All tested compounds provided significant disease suppression and increased yields, provided that a sufficient rate of fungicide was applied. Ronilan and Rovral, the two fungicides currently registered for use on lettuce for Sclerotinia leaf drop, were the most effective fungicides in this test, performing significantly better than the two experimental materials. The SODF formulation of Ronilan provided significantly better disease control than the SOW formulation of the same compound.