Trichoderma fungi are among the most extensively utilized biological active ingredients in sustainable agriculture, helping to prevent crop diseases and minimize the need for synthetic pesticides. Because they are mass-produced and distributed, understanding their behavior and potential environmental consequences has become increasingly crucial. This is underscored by an international study published in Nature Microbiology, in which the University of Pisa also took part. The study contributes to a better understanding of why Trichoderma is so efficient at reducing infections and demonstrates how to select strains best suited for agricultural usage from others that require more caution. The suggested method combines genetic analysis and ecological behavior observation to identify species capable of crop protection while reducing the risk of propagation and persistence in the environment. Over 140 biological characteristics related to metabolism, resistance to environmental duress, dispersal capacity, and reproductive strategies were evaluated by researchers on 37 Trichoderma species. Many of the studied species are mycoparasitic, meaning they live at the cost of other fungi, the majority of which are detrimental to plants. Because of their ability, they serve an essential role as biocontrol agents, naturally limiting the spread of plant diseases. At the same time, the examined species exhibited significant behavioral variety. Some, if not carefully selected, can take advantage of favorable conditions and cause unforeseen consequences, such as spread outside the treated region, interference with other beneficial organisms, or issues in specific agricultural habitats. These effects have been recorded mostly in edible mushroom cultivation, with only isolated cases in cultivated plants. In some situations, certain species have been linked to plant diseases, problems with cultivated mushroom production, and, very infrequently, human infections in the presence of specific vulnerability factors. "This work not only increases the accessibility of sustainable agriculture but also raises awareness of the importance of a comprehensive understanding of the biological characteristics of beneficial organisms and the potential long-term effects on the environment and non-target organisms", the researchers explain.