Preface

*Trichoderma* spp. is a versatile fungus with a high reproductive capacity and great potential for application in the biological control of plant diseases. It stands out for the control of phytopathogens with use via seed, soil, and straw and has action or interaction with bacteria, actinomycetes, and mycorrhizas, improving its action in hyperparasitism and antibiosis. It can also be used in the production of biofuels through the degradation of cellulose and even pharmacologically. *Trichoderma* antagonism against sclerotia producers may be imposed by different mechanisms such as mycoparasitism, antibiosis, competition, resistance induction, and plant growth promotion. The niche competition for space and nutrients besides antibiosis are the mechanisms most often used by biocontrol agents and one of the main *Trichoderma* strategies. The fast reproduction and colonization confer more effectiveness in available resources using. The successful antagonism could be attributed to the combined action of secondary metabolites and hydrolytic enzymes. The *Trichoderma* mycoparasitism relationship against pathogens may involve events such as location, recognition, direct contact, formation of hook-shaped structures with appressorium function, penetration, folding, and development of parallel hyphae. Biological control products formulated with *Trichoderma* have emerged as the best methods to manage sclerotia-producing pathogens, since chemicals in soil are often inefficient, too expensive, and too environmentally harmful. All *Trichoderma* species can utilize the cell content of other fungi as a source of nutrients. Control of white mold is also dependent on the density of sclerotia in soil. Best results are obtained when the densities are 1–10 sclerotia/kg of soil. Field experiments have shown that *Trichoderma* spp. as an exclusive control method is not sufficient to reduce the severity of white mold. In Brazil and other parts of the world, thirty-four *Trichoderma*-based products are currently registered and most of them are recommended to control soil-borne pathogens that produce sclerotia as resistance structures. Relatively few species of *Trichoderma* were developed into commercial formulations, despite the large number of publications that have shown the potential of many other species. *Trichoderma* spp. are widely used in Brazil to control white mold in soybean and its use is expected to increase, as only 50% of the infected area is currently treated with these biocontrol agents. Besides providing partial control of white mold, these fungi can also increase plant growth and productivity coupled with a reduction in the use of chemical fungicides.

#### **Fernando Cezar Juliatti**

Micology and Plant Protection Laboratory, Agrarian Institute Science of University, Federal of Uberlândia, Minas Gerais State, Brazil

**1**

Section 1

Identification of *Trichoderma*

Species, Register Products and

Uses in Biology Control
