Biological control of Sclerotinia sclerotiorum (Lib.) de Bary with Trichoderma harzianum and Bacillus amyloliquefaciens

The survival of Sclerotinia sclerotiorum, to a large extent depends on the production and viabilty of sclerotia. Reduction in the production of sclerotia is essential in the control of the pathogen. A local Trichoderma harzianum isolate and two Bacillus amyloliquefaciens isolates were evaluated in vitro and in vivo as potential biological control agents (BCAs) against S. sclerotiorum. The study showed that T. harzianum and B. amyloliquefaciens inhibited the growth and production of mycelia and sclerotia. The local isolates, T. harzianum and B. amyloliquefaciens appeared to exhibit mycoparasitism and antibiosis, respectively, in the in vitro study. As antagonists, these isolates protected over 80% of tomato, squash and eggplant seedlings inoculated with S. sclerotiorum. The efficacy of T. harzianum and B. amyloliquefaciens compared with two commercial products, PlantShield and SoilGard in the control of S. sclerotiorum was similar or slightly lower depending on the crop plant.