Abstract

A.PEREZ, A. et al. Selection of Trichoderma spp. isolates in vitro as potential biofungicides for the control of Rhizoctonia solani Kühn on potato. Agriscientia [online]. 2020, vol.37, n.2, pp.21-30. ISSN 1668-298X.  http://dx.doi.org/10.31047/1668.298x.v37.n2.29419.

Quality and performance in potato production systems is seriously affected by fungi diseases such as R. solan¡, whose Chemical control is inefficient. The objective of the present work was to select isolates of Trichoderma spp. ¡n vitro as potential biofungicides for the control of Rhizoctonia solani on potato. From soil samples from Calamuchita, Río Primero, Punilla and San Javier departments in the Province of Córdoba (Argentina), 18 native Trichoderma strains were isolated and genetically ¡dentifled. They were evaluated in vitro by the dual culture method on their competence for the substrate, mycoparasitism and antibiosis capacity. It was possible to identify a group of flve promising strains: T atroviride ACp8 y CBa3, T konigiopsis CBk2 y CBk4 y T harzianum CBh2. These strains had more than 85 % overgrowth over the pathogen, were very competitive for the substrate (Grade 1) and had an antibiosis capacity higher than 35 % which inhibited radial growth through at least four mechanisms of hyphal interaction against R. solani. The selected strains that specifically recognize the phytopathogen and due to their native condition present high edaphoclimatic adaptation, may be incorporated into crop management improving the system sustainability.

Keywords : biological control; infection; action mechanisms; rhizoctoniasis.

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