Evaluation of the fungistatic activity of biopreparations against the main pathogens of highbush blueberry (Vaccinium corymbosum L.)

Abstract

Goal. To evaluate the fungistatic activity of the preparations LS-1, WS (silver lactate, 1 g/l silver) and Mikosan, LC (alkaline extract of the aphyllophorous fungus Fomes fomentarius, 30 g/l + glucans, 6 g/l) against fungal pathogens of the genera Neopestalotiopsis, Fusarium and Rhizoctonia under in vitro conditions. To analyse the dynamics of radial mycelial growth and to determine the dose-dependent effect. Methods. The studies were conducted under laboratory conditions. The ‘poisoned medium’ method was used to assess the fungistatic activity of the preparations LS-1, WS and Mikosan, LC. Pathogen isolates belonging to the genera Neopestalotiopsis, Fusarium and Rhizoctonia, isolated from blueberry plant material, were studied. Results and discussion. It was found that LC-1, WS (at concentrations of 0.25% and 0.5%) had low fungistatic activity, which was limited to the initial stages of cultivation (3—6 days). By day 10, the mycelium of all pathogens had fully recovered from the inhibition. The biofungicide Mikosan, LC demonstrated a clearly dose-dependent effect. At a concentration of 0.5%, a moderate fungistatic effect was observed against all the pathogens studied, whilst at a concentration of 5%, it ensured complete inhibition of mycelial growth throughout the entire observation period (10 days), demonstrating high fungicidal activity. The highest sensitivity to Mikosan, LC was observed in R. solani. The results obtained confirm a difference in fungistatic activity between the preparations: LS-1, WS has a weak effect, whilst Mikosan, LC demonstrates a pronounced dose-dependent fungistatic and fungicidal effect against various pathogens. Conclusions. It has been established that Mikosan, LC exhibits a pronounced dose-dependent effect. At a concentration of 0.5%, it exerts a fungistatic effect, accompanied by a significant reduction in the rate of radial growth and a prolongation of the lag phase of development by 2—3 days. At a concentration of 5%, a fungicidal effect was observed against all the pathogens studied. The results obtained provide scientific justification for the use of Mikosan, LC as a promising agent for the biological control of fungal pathogens.