Effect of disinfectans and Em preparations on the growth inhibition of Lecanicillium fungicola Occirring in cultivation of bitton muschroom (Agaricus bisporus)

Background. The dry bubble disease, caused by Lecanicillium fungicola, is the most common fungal disease of white button mushroom (Agaricus bisporus). The aim of this study was to estimate the effectiveness of two chemical agents based on periacetic acid and biopreparations Effective Microorganisms (EM) in inhibiting the growth of L. fungicola isolated from infected fruiting bodies of button mushrooms. Material and methods. The material was the pathogen L. fungicola isolated from bottom mushrooms, treated with disinfectants: Agrosteril (in concentration 1, 1.5, 2, 2.5, 3, 3.5%), Larasept (in concentration 0.2%, 0.5%, 1%) and various configurations with biopreparations based on effective microorganisms (EM). The activity of the chemical preparations was assessed in a plate (on PDA medium) and pot experiment (in infected casing soil). The fungicidal efficacy of EM preparations was performed only in vitro. Results. In a plate experiment Agrosteril disinfectant caused the complete inhibition of pathogen development at each tested concentration. In the case Lerasept the lack of mycelium growth was obtained only after the application of the highest dose of 1%. Biopreparation EM-5 and its combination with EM-NA in a dose of $100 mg·cm^(-3)$ of the medium turned out to be the most effective of EM preparations in inhibiting the development of L. fungicola. Those preparations also caused a significant decrease in sporulation of the pathogen. Chemical preparations applied in the form of sprinkling to the casing infected with the fungi turned out to be less effective. The highest decrease in the pathogen number was obtained on 7th day from inoculation of the casing. Conclusion. Tested disinfecting preparations were characterized by strong fungicidal properties in vitro. Based on the pot experiment it was found that chemical preparations used for disinfecting the casing, applied in doses recommended by the producer, caused only a partial inactivation of L. fungicola.

Celem badań było określenie skuteczności środków chemicznych Agrosteril i Lerasept oraz preparatów na bazie efektywnych mikroorganizmów EM w hamowaniu rozwoju patogenicznego grzyba Lecanicillium fungicola wyizolowanego z uprawy pieczarek. W doświadczeniu płytkowym preparat Agrosteril w każdym testowanym stężeniu (1%, 1,5%, 2%, 2,5% 3%, 3,5%) powodował całkowite zahamowanie rozwoju patogena. Natomiast pod wpływem Leraseptu brak wzrostu grzybni stwierdzono tylko po zastosowaniu najwyższej dawki 1%, zaś w niższych koncentracjach 0,2% i 0,5% jego działanie było słabsze. Spośród preparatów EM najbardziej skutecznym okazał się EM-5 i jego kombinacja z EM-NA w dawce $100 mg·cm^(-3)$ pożywki. Preparaty te również powodowały istotny spadek zarodnikowania. Na podstawie doświadczenia wazonowego stwierdzono, że użyte do odkażania okrywy preparaty chemiczne powodowały tylko częściową inaktywację L. fungicola.