Control of Gardenia Leaf Spot and Bud Rot Diseases Using Some Natural Plant Oils

摘要

This study was conducted to through light on the most important fungi affected gardenia (Gardenia jasmenoides Ellis) plant with leaf spot and bud rot diseases and the effect of some plant essential oils as safe management against these fungi in vitro and in vivo. Isolation trials from infected gardenia plant tacken from Giza governorate during 2010-2011 growing season revealed eleven fungal species related to eleven genera. Botrytis cinerea, Alternaria alternata, Pestalotia langloissii and Cladosporium sp. were the most dominant fungi. These four isolates were differed in there pathogenic capabilities depending on the infected plant part, B. cinerea was exhibited the highest percentage of rotted buds while A. alternata and P. langloissii were only infected the leaves. A. alternata was exhibited the highest disease severity. Among twenty plant essential oils tested in vitro, Cumin (Cuminum cyminum) oil was the most effective one, completely inhibited the mycelial growth of the tested fungi at 500 ppm. Generally spraying gardenia plant by cumin oil at 2500 ppm. mixed with clove oil at 5000 ppm. concentration was the best treatment that significantly decreased the disease incidence under greenhouse conditions.