Economical Biological Control of Sclerotinia Lettuce Drop bySporidesmium sclerotivorum

In a field trial, lettuce plants infected with Sclerotinia minor were treated with a preparation of Sporidesmium sclerotivorum at rates of 0, 0.2, 2, or 20 kg/ha of Sporidesmium product in May 1987. From the fall of 1987 to the fall of 1989, five successive lettuce crops were grown in this field with no additional application of the biocontrol agent. Disease incidence was significantly lower than th nontreated plots at the highest, two highest, and all three rates in the first, second, and third crop, respectively. In the third crop, 53, 68, and 72% disease control was obtained at the 0.2, 2, and 20 kg/ha rates, respectively (...)