*3.1.1 Isolation and morphological identification of Trichoderma spp.*

The first step for correct identification of antagonist microorganisms depends on isolation. In the case of *Trichoderma* spp., they are present in a great variety of agricultural and natural soils. The soil sampling for its isolation is relatively simple; using a shovel at 10–20 cm depth, 500 g of soil is taken and deposited in plastic bags; after, the samples will be moved to a laboratory and placed on storage at 4°C until used. Purification of *Trichoderma* spp. it is essential on investigations and present many ways or techniques; nevertheless, the monosporic culture is suggested by Trichoderma on culture media as potato dextrose agar (PDA) or *Trichoderma* Specific Medium (TSM), and incubated at 28 ± 2°C for 96 h [11–13]. Once the monosporic culture is obtained, the identification of *Trichoderma* species can be realized using taxonomic keys through its morphological features or with molecular biology, extracting DNA and utilizing general or specific primers. In case of the use of taxonomic keys, structures as width and length of phialide, length and width of conidia, and presence of chlamydospores will be observed [7, 14].
