The influence of different doses of copper and organic substances on the genus composition and intensity of the occurrence entomopathogenic fungi in the soil

Abstract

The aim of the study was to determine the effect of copper application in combination with organic materials on the genus composition and the intensification of the occurrence of entomopathogenic fungi in the soil. The three-year pot experiment was carried out in greenhouse conditions. The experiment was set up in a completely random design, taking into account two factors: copper dose and organic fertilization. Soil samples for the tests were collected in the third year of the experiment, in spring (before the beginning of vegetation) and in autumn (after harvesting the last crop). The experimental plant was cocksfoot, Amera cultivar. Entomopathogenic fungi from individual research objects were isolated by sowing on a selective substrate. The results were expressed as the number of CFUs of each genus of entomopathogenic fungus in 1 g of soil. The presence of entomopathogenic fungi of the genus Beauveria, Metarhizium, Cordyceps and Lecanicillium was found in the soils collected from the experimental sites, where the dominant genus was Metarhizium spp. In the spring period of conducting the research, the level of copper application affected the number of CFU in a different way, while in the autumn the application of copper at a dose of 200 mg/kg of soil was a level that did not show any toxic effects, and even stimulated the growth of fungal colonies of the genus Beauveria, Metarhizium, Cordyceps in relation to a copper dose of 100 mg/kg.