In vitro interactions between Armillaria sp. and Trichoderma sp. collected from mushroom crop residues

Resumen

Armillaria mel/ea (Agaricales: Physalacriaceae) is a fungus naturally occurring in the soil, which may penetrate the grapevines' roots, causing their death in the long term. Many chemical products have been tested to manage this fungus with limited success. Nowadays, uprooting and non-prolonged cultivation is the only field-allowable and effective solution. Trichoderma is a well-known fungus used as a biocontrol agent. However, it is also known to be a contaminating fungus far the cultivation of mushrooms (Agaricus sp.). We hypothesized that T. Harzianum from contaminated mushroom cultivation is an effective biological control agent of A. mellea in vitro and could be used as a treatment in the vineyard. In this sense, a circular economic model would be favored in which, on the one hand, the waste reuse from mushroom cultivation would be encouraged, and on the other hand, an effective and sustainable solution would be proposed to combat sorne fungal diseases. To accomplish this, field strains of T. Harzianum and A. mellea were isolated on Malt Extract Agar (MEA). Dual confrontation tests on Patato Dextrose Agar (PDA) plates were performed to evaluate the inhibitory effect of the T. harzianum strain on A mellea. Far this purpose, A. mellea was plated 14 days befare T. harzianum. The two fungi were also individually cultivated as positive controls. AII plates were kept at 25ºC throughout the experiment. We observed that T. harzianum inhibited the in vitro growth of A. mel/ea. Specifically, the A. mel/ea growth stopped when both fungi met, while T. harzianum continued to grow above A. mel/ea. The results obtained support our hypothesis of the potential of T. harzianum as a biocontrol agent far A. mel/ea. However, it must be validated in field experiments. Future research will facus on analyzing whether mushroom crop residues infected with T. harzianum could be reused as an organic mulch treatment against A. mellea in the vineyard.