Testing of eight medicinal plant extracts in combination with kresoxim-methyl for integrated control of botrytis cinerea in apples
Date
2015Author
Fielding, Burtram C.
Knowles, Cindy-Lee
Vries, Filicity A.
Klaasen, Jeremy
Metadata
Show full item recordAbstract
Botrytis cinerea is a fungus that causes gray mold on many fruit crops. Despite
the availability of a large number of botryticides, the chemical control of gray mold has
been hindered by the emergence of resistant strains. In this paper, tests were done to
determine the botryticidal efficacy of selected plant extracts alone or combined with
kresoxim-methyl. In total, eight South African medicinal plants viz Artemisia afra,
Elyptropappus rhinocerotis, Galenia africana, Hypoxis hemerocallidea, Siphonochilus
aetheopicus, Sutherlandia frutescens, Tulbaghia violacea and Tulbaghia alliacea were
screened. Allium sativum, a plant species known to have antifungal activity, was included
in the in vivo studies. For the in vitro studies, synergistic interactions between the plant
extracts and the kresoxim-methyl fungicide were tested with radial growth assays. Data
indicated synergistic inhibitory effects between the fungicide and the plant extracts. Next,
different doses of plant extracts combined with kresoxim-methyl were used for decay
inhibition studies on Granny Smith apples. Synergistic and additive effects were observed for many of the combinations. Even though this study was done using only one strain of
B. cinerea, results showed that the tested indigenous South African plant species possess
natural compounds that potentiate the activity of kresoxim-methyl.