Sensitivity of Trichoderma strains from edible mushrooms to the fungicides prochloraz and metrafenone

Abstract

Twenty-two strains of Trichoderma spp. (T. harzianum species complex [THSC], Trichoderma aggressivum f. europaeum, Trichoderma pleuroti, and Trichoderma pleuroticola) causing green mold disease on edible mushrooms (button mushroom, shiitake and oyster mushroom), collected during 2004–2018 from four countries (Serbia, North Macedonia, Croatia, and Hungary) were examined. Based on their ITS (internal transcribed spacer) sequences, strains from shiitake mushroom in Serbia were identified as members of the THSC, while in samples obtained from Serbian and North-Macedonian oyster mushroom farms THSC, T. pleuroti and T. pleuroticola were detected, which represent the first findings in the region. In fungicide susceptibility tests, all examined Trichoderma strains were found to be highly sensitive to prochloraz (ED₅₀<0.4 µg mL⁻¹) and considerably susceptible to metrafenone (ED₅₀ < 4 µg mL⁻¹). The most sensitive taxon to both fungicides was THSC from oyster mushroom. The toxicity of metrafenone was satisfying and strains from oyster mushroom showed the highest sensitivity (ED₅₀ < 1.43 µg mL⁻¹), while strains originating from button mushroom and shiitake displayed similar susceptibilities (ED₅₀ < 3.64 µg mL⁻¹). After additional in vivo trials, metrafenone might also be recommended for the control of green mold disease in mushroom farms.

Keywords:

• Button mushrooms
• oyster mushroom
• shiitake
• green mold disease
• fungicide sensitivity test
• disease control
• Trichoderma pleuroti
• Trichoderma pleuroticola
• Trichoderma harzianum

Disclosure statement

We confirm that the research described in the manuscript is the original work of the authors that has not been previously published, in whole or in part, and that it is not under consideration by any other journal.

Additional information

Funding

The study was carried out with financial support by the Science Fund of the Republic of Serbia within Programme under Grant for Scientific Research Organisations 451-03-68/2020-14/200214; the Hungarian Government and European Union under Grant GINOP-2.2.1-15-2016-00006, Széchenyi 2020 Programme; and the National Research, Development and Innovation Office under Grant NKFI K-116475.