Fungi from the genus Trichoderma have been extensively studied and used as biological control agents (BCAs) because of their versatile mechanisms of action. These include triggering systemic resistance, directly inhibiting pathogens, promoting plant growth, enhancing tolerance to abiotic stress, and producing auxins. However, the widespread application of the most studied Trichoderma strains has been limited by discrepancies between their potential results observed in controlled environments and the outcomes in greenhouses and field conditions. These differences are associated with context dependency, influenced by strain-specific traits, crop genotype, soil properties, and environmental factors. In this review, we examine the mechanisms of action, current challenges, and opportunities, emphasizing the importance of local strategies and detailed characterization of native strains to boost the effectiveness of Trichoderma-based products in sustainable agriculture.

Potatoes (Solanum tuberosum L.) represent an important food in the country’s gastronomy due to their cost, nutritional contribution, and versatility. However, many plant diseases such as the common scab—caused by Streptomyces species—reduce its yield and quality. This study aims to determine Streptomyces species being the causal agent of common scabs in a commercial potato field in the Yaqui Valley, Mexico, while identifying Bacillus strains as a biological control method to mitigate the impact of this disease under field conditions. Thus, three Streptomyces strains were selected from symptomatic samples, and then they were morphologically and molecularly (through sequencing recA and rpoB genes) identified as Streptomyces caniscabiei. After pathogenicity tests, the three strains were found to be pathogenic to potato tubers. In screening assays to identify biocontrol bacteria, strain TSO2^T (Bacillus cabrialesii subsp. tritici) and TE3^T_UV25 (Bacillus subtilis) had the best in vitro biocontrol effect against S. caniscabiei. Then, a field experiment (1 ha per treatment), under commercial conditions, was carried out to analyze the effectivity of these biocontrol bacteria to mitigate the common scabs on potato crops. After four months, the inoculation of this bacterial consortium decreased common scab incidence from 31% to 21% and increased the potato yield up to almost 5 tons/ha vs. the un-inoculated treatment. These findings demonstrate the effectiveness of the studied bacterial consortium as a potential biological control strategy to control common scabs of potato caused by Streptomyces caniscabiei, as well as increase the potato yield in the Yaqui Valley, Mexico.