Trichoderma shapes phytophagous and entomophagous arthropod community in common bean fields

Trichoderma afroharzianum is one of the main beneficial endophytic fungi used in agriculture to promote plant health and increase yields, promoting plant growth and inducing resistance. In this study, the effects of T. afroharzianum strain T22 on the growth and physiology of the common bean plant (Phaseolus vulgaris L.), seed production, and its impacts on phytophagous and entomophagous arthropod community were evaluated for the first time under field conditions. Trichoderma was applied as a spore suspension to root via soil drenching in two bean fields during 2024 season. Monitoring of arthropod populations was carried out using chromotropic traps and leaf sampling during the whole productive cycle. Our results proved that T. afroharzianum T22 promoted plant growth and increased bean seed production under field conditions. Nevertheless, Trichoderma also influenced the populations of certain phytophagous arthropods, by boosting the aboundance of the two spotted spider mite (Tetranychus urticae Kock) and the rate of seed damage caused by stink bugs’ feeding. Nevertheless, although Trichoderma treatment determined an increase in stinkbug damages on seed, it was compensated by whole yield increment, with higher total marketable seed production for both fields. Therefore, T. afroharzianum strain T22 may contribute to reduce agrochemical inputs used to promote plant growth.