SPECIES OF THE Rhododendron l. GENUS ON THE COAST OF ADJARA AND THE ANTIMICROBIAL ACTIVITY OF THEIR LEAF EXTRACTS AGAINST PHYTOPATHOGENS

Abstract

Based on the Institute of Phytopathology and Biodiversity of Batumi Shota Rustaveli State University, studied the antimicrobial action of the extracts obtained from the leaves of the species: Rhododendron japonicum, Rhododendron arborescens, Rhododendron brachycarpum, Rhododendron macrosepalum, Rhododendron dalavayi, on the example of fungicidal and fungistatic actions. The experiments were mainly conducted during periods of active vegetation.  It has been determined: extracts obtained from Rhododendron dalavayi and Rhododendron brachycarpum are characterized by very high antimicrobial action. The highest fungicidal activity was observed in the case of dilution of ethanol extract 1:1, 1:2, in the case of fairly high dilutions of 1:4and 1:8, in the rest of the cases there was a clearly expressed fungistatic activity; in the case of aqueous extracts (tinctures), high fungicidal action was detected in relation with fungi Phytophtora infestans, Alternaria alternata, Alternaria   solani, Pestalotia theae, Fusarium moniliforme, whereas fungistatic – in relation with the fungi Trichothecium roseum, Pestalotia  coryli,  Fusarium moniliforme. The rest of the species of Rhododendron under study are characterized by weakly expressed fungistatic activity.  The high antimicrobial activity of the extracts of the leaves of Rhododendron dalavayi and Rhododendron brachycarpum is of interest for the purpose of practical use.