Fusarium genus is a wide host phytopathogen causing significant losses in multiple crops, including hops. There is limited information on the sustainable management of Fusarium spp. in hop fields. Trichoderma is an endophytic fungus used in agriculture as a biological control agent (BCA) and as a plant growth promoter. It has been used to antagonize Fusarium spp. in other crops. The objective of the current study was to identify indigenous hop field Trichoderma isolates with biocontrol and hop growth promotion capabilities. Three isolates of Fusarium and eleven autochthonous Trichoderma isolates collected from sustainable hop fields were evaluated in this work. Direct confrontation tests (the physical interaction between the pathogen and BCA and their competition for space and nutrient resources) and membrane tests (the capacity of the BCA to produce metabolites or enzymes through a cellophane film and inhibit the development of the pathogen) assessed the antagonism of these Trichoderma isolates against Fusarium culmorum, F. sambucinum, and F. oxysporum. A bioassay with hop plantlets inoculated with a spore suspension of Trichoderma was performed to assess its hop growth enhancement. T. hamatum (T311 and T324), T. virens T312, and T. gamsii T327 showed high growth inhibition of Fusarium spp. phytopathogens and high plant growth promotion. Native Trichoderma isolates from sustainable hop-producing soils have great potential as BCAs and hop growth promoters.

Acanthoscelides obtectus is an insect pest that attacks wild and cultivated common beans (Phaseolus vulgaris L). Four Trichoderma strains, the T. arundinaceum IBT 40837 wild-type strain (=Ta37), a producer of trichothecene harzianum A (HA), two transformants of T. arundinaceum strain, Ta37-17.139 (=Δtri17) and Ta37-23.74 (=Δtri23), and the T. brevicompactum IBT 40841 wild-type strain (=Tb41), which produces the trichothecene trichodermin, were assessed to establish their direct effect on insect attacks and their indirect effect on the plants grown from the beans treated with those fungal strains and exposed to insect attacks. Treatments of bean seeds with different Trichoderma strains led to different survival rates in the insects, and the Tb41 strain caused the lowest survival rate of all. An 86.10% of the insect cadavers (in contact with Δtri23) showed growth of this strain. This was the treatment that attracted the greatest number of insects. The daily emergence was reduced in beans treated with the Ta37, Tb41, and Δtri17 strains. The undamaged beans treated with Ta37 and Δtri23 showed a high capacity of germination (80.00% and 75.00%, respectively), whereas the Δtri17 and Tb41 treatments increased the capacity of germination in the damaged beans (66.67%). The undamaged beans treated with Δtri23 had the greatest dry weights for the aerial part (4.22 g) and root system in the plants (0.62 g). More studies on the mechanisms of insect control, plant growth promotion, and trichodermol and trichodermin production by Δtri23 and Tb41, respectively, should be explored in order to commercialize these fungal species on a large scale.