Potential for Biocontrol ofSclerotinia sclerotiorumThrough Colonization of Sclerotia byTrichoderma harzianum

In the laboratory, Trichoderma harzianum strain ThzID1, formulated as mycelial fragments in alginate pellets with or without wheat bran incorporated, colonized sclerotia of Sclerotinia sclerotiorum in raw or steamed soil. Incidence of colonization was higher in steamed soil than in raw soil, higher at 25 C than at 15 C, and higher at −500 kPa than at −50 kPa but was not affected by bran in pellets. Some sclerotia were colonized by indigenous Trichoderma spp. Pellets containing T. harzianum were added to soil in a pea (Pisum sativum) field or field microplots at densities of 4 × 10 2 − 2 × 10 4 pellets per square meter, along with sclerotia of S. sclerotiorum (.)