**5. Fungi of the genus** *Trichoderma* **and the biological control of diseases**

Fungi of the genus *Trichoderma* are biological control agents that act against phytopathogenic edaphic fungi, however, colonizing plant roots to stimulate plant growth and protect them against infections. Root colonization often increases root development, crop productivity, resistance to abiotic stresses, and improved nutrient use [69].

Fungi present different mechanisms to controlling and suppressing the soil's phytopatho‐ gens, such as mycoparasitism, antibiosis and antagonism [70]. In addition, *Trichoderma* strains are active in the production of fungal cell walls, enzymatic degradation, including pectinases, cellulases, and chitinases, involved in the biological control [71].

Compared to the chemical control, the use of biological substances to control soil diseases is beneficial, since it does not induce resistance from the target organism, effectively controlling it in a long term. There are currently commercial products based on genus *Trichoderma* strains, properly registered in the Brazilian Ministry of Agriculture, Livestock, and Food Supply (MAPA) that are indicated for the controlling of diseases caused by phytopathogenic agents, such as *Rhizoctonia*, *Fusarium*, and *Sclerotinia* [72]. Harman [4] and Machado et al. have described the benefits of *Trichoderma* inoculation on grass yield, observing an increase in maize and black oat yields, respectively.
