Chapters authored
Trichoderma as a Biocontrol Agent against Sclerotinia Stem Rot or White Mold on Soybeans in Brazil: Usage and Technology
Biological control agents are alternatives to chemical pesticides in the management of plant diseases. Currently, hundreds of bioproducts are commercially available in international market varying mainly in antagonistic microorganisms and formulation. We screened four Trichoderma-based products as to their efficacy in controlling Sclerotinia stem rot (SSR) under protected and field environments and their effect on soybean seeds’ sanity and physiological qualities. We also tested application technologies through seed microbiolization and foliar spraying to deliver the microorganisms, and their compatibility with chemical fungicides. In vitro assays showed that all Trichoderma strains were antagonistic to S. sclerotiorum evidencing hyperparasitic activity. Moreover, the bioproducts reduced fungi incidence on soybean seeds, promoted faster seedling emergence and did not hamper seeds’ vigor. Increases of 14 and 37% were registered for root length and shoot fresh weight over that of the untreated control indicating potential application of the bioproducts as soybean growth promoters. Thiophanate-methyl and procymidone were the most compatible, without drastically affecting spore germination or mycelium growth. Under field conditions, all Trichoderma strains reduced SSR incidence and increased soybean grain yield. Formulation interferes on bioproducts’ viability and efficacy deserving special attention upon development.
Part of the book: Trichoderma
Using Trichoderma to Manage Sclerotia-Producing Phytopathogenic Fungi
Sclerotia are resistance structures that allow several soil-borne plant pathogens to survive for extended periods of time. The white mold disease, caused by Sclerotinia sclerotiorum and the stem rot in Allium spp., caused by Stromatinia cepivora are examples of destructive pathogens in which sclerotia are the central survival structure in their life cycle. In this chapter, we explore the information on the use of Trichoderma to manage sclerotia-producing pathogens in Brazil. There are 34 registered commercial products registered in Brazil, and most of them are recommended to manage sclerotia-producing fungi. The mechanisms of action of Trichoderma against these pathogens involve mainly mycoparasitism. The number of species employed as active ingredients of these commercial products is very limited, although many other species have shown a high potential against these pathogens. The white mold pathogen in soybean was taken as an example of field management, where the technical recommendations are detailed. This management involves other practices in addition to the application of Trichoderma in an integrated manner, and they are essential to manage this disease in the field in Brazil.
Part of the book: Trichoderma