Özet:

This study focused on isolating antagonistic bacteria from vineyard areas in Sarigol/Manisa Province and using them for biological control against Gray Mold Disease caused by Botrytis cinerea. Biological efficiencies of antagonists were investigated by in-vitro and in-vivo studies. The compatibilities of the antagonists with azoxystrobin and cyprodinil + fludioxonil, which are active ingredients of fungicides, were also examined. A total of 11 B. cinerea strains were isolated, and the B33 isolate was used as the most virulent disease isolate across the study. A total of 160 putative antagonistic bacterial isolates were obtained from healthy grape plants. Among them, 17 bacterial isolates inhibited mycelial growth of the fungal agent by between 6.8% and 80.1% in in-vitro dual culture tests. The antagonistic bacteria were Bacillus halotolerans, B. licheniformis, B. safensis, B. subtilis, B. velezensis, Kosakonia cowanii and Pseudomonas aeruginosa. Of the 17 antagonists, 13 were Bacillus species, while seven of them were strains of B. velezensis. In plant studies conducted with the A7Len4, A1Len4 and A8Len1 isolates, an efficacy of between 71.43% and 80.96% against the disease was determined. All three antagonists werecompatible with up to two applications of azoxystrobin.