Modification in the pathogenicity of the <i>Pyrenophora teres</i> population under the influence of fungicides of the triazole and strobilurin classes

The research examined the effects of fungicides of chemical classes (triazole and strobilurine) (Amistar Gold, SC, 1 l/ha; Amistar Extra, SC, 1 l/ha; Delaro, CS, 1 l/ha) on the pathogenicity of the causative agent of net blotch of barley (ascomycetes Pyrenophora teres). A change in the aggressiveness of the fungal population was revealed after the introduction of fungicides in various concentrations into the nutrient medium according to the following indicators: the diameter of colonies of the fungus P. teres (Amistar Gold, SC – 33.1 mm, Amistar Extra, SC – 32.1 mm, Delaro, CS –31.9 mm, control – 27.0 mm), a decrease in the latency period (Amistar Gold, SC – 5.1 days, Amistar Extra, SC – 5.6 days, Delaro, CS – 4.8 days, control – 6.2 days), and average virulence of populations (Amistar Gold, SC 2.8 points, Amistar Extra, SC – 2.4 points, Delaro, CS – 1.9 points, control 3.6 points) in comparison with the variant without fungicides treatments. The suppression of the physiological processes of the phytopathogenic fungus, a decrease in the virulence of the population and a pathological acceleration of the processes of mushroom maturation under the influence of fungicides based on triazoles and strobilurines were determined.