CEPAS NATIVAS DE Trichoderma PARA EL CONTROL DEL MOHO GRIS (Botrytis cinerea Pers.) EN FRUTOS Y FLORES DE ARÁNDANO (Vaccinium corymbosum L.)

<p><strong>Background.</strong> Gray mold disease caused by <em>Botrytis cinerea </em>Pers. is a phytosanitary problem in blueberry (<em>Vaccinium corymbosum</em> L.). It is characterized for affecting soft tissues (flowers and fruits) in the field and in the post-harvest stage, reducing crop yield. This has motivated to the search for native strains of <em>Trichoderma</em> that are effective in biological control. <strong>Objective.</strong> To determine the effect of 19 native <em>Trichoderma</em> strains on the control of gray mold on flowers and fruits of blueberry under laboratory conditions. <strong>Methodology.</strong> Under a complete randomized experimental design, mycoparasitism and antibiosis tests were carried out to evaluate colonization and mycelial inhibition of the pathogen, respectively, using the dual confrontation method and production of secondary metabolites. For the bioassays, a suspension of 1×10<sup>6</sup> conidia mL<sup>-1</sup> per strain was sprayed on blueberry flowers and fruits. Disease incidence and severity were evaluated. Data were analyzed with the statistical program InfoStat. <strong>Results.</strong> All <em>Trichoderma</em> strains completely colonized the pathogen, being considered as aggressive mycoparasites and inhibited the mycelial growth of the pathogen up to 42.74%. Likewise, the application of <em>Trichoderma</em> spore suspension had inhibitory effects on gray mold, highlighting the strain HE- ArT161 that reduced the incidence (66.67% and 20%) and severity (34% and 12%), respectively in flowers and fruits. <strong>Implications.</strong> The use of these native strains of <em>Trichoderma</em> may contribute to future research in the field where they can be incorporated for an integrated management of the disease. <strong>Conclusion.</strong> These <em>Trichoderma</em> isolates against <em>B. cinerea</em> showed <em>in vitro</em> control, stimulating mycelial inhibition of the pathogen and reducing the development of disease lesions.</p>