Effect of Biopesticides on the Growth and Development of Isolates of Botrytis Cinerea Pers., in vitro Obtained from Raspberry Plants

Two Botrytis cinerea isolates studied in the experiment responded differently to the fungicides applied. An isolate obtained from raspberry fruit infected by the fungus, was more susceptible to the biopesticides as well as the fungicide Signum 33 WG. Efficacy of the biopesticides differed. Their efficacy, which depended on both the active ingredient and the duration of biopesticide influence on the mycelium. B. cinerea, was rather resistant to the biological pesticides. The growth of both the isolates was completely inhibited at a concentration that was fivefold higher than the recommended amount and the recommended concentration, but only at the initial stage of culturing. Of the biopesticides, Biosept 33 SL was most effective at controlling the growth of B. cinerea. No sclerotia were formed on media containing the biopesticide. Propolis also inhibited the production of spores; however, the biopesticide effectively controlled the development of mycelium only when applied at the highest rate. The synthetic fungicide Signum 33 WG is conventionally applied to control grey mould. Signum 33 WG was highly effective at controlling both the B. cinerea isolates.