ARS | Publication request: Fungicidal activity of the plant saponin, CAY-1, for fungi isolated from diseased Vitis fruit and stems

Submitted to: American Journal of Enology and Viticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 16, 2007
Publication Date: March 1, 2008
Citation: De Lucca Ii, A.J., Klich, M.A., Sien, T., Boue, S.M., Cleveland, T.E., Walsh, T.J. 2008. Fungicidal activity of the plant saponin, CAY-1, for fungi isolated from diseased Vitis fruit and stems. American Journal of Enology and Viticulture.59:67-72.

Interpretive Summary: Fungi that cause economically serious grape diseases were isolated from grapes grown in a hot, humid environment. CAY-1, a fungicide from cayenne pepper, was mixed at very low doses to determine whether it would kill these fungi. Results show that it kills almost all the fungi at the test concentrations. It is possible that this plant-produced fungicide could be useful in preventing fungal infection of grapes on the vine or after harvesting.

Technical Abstract: Members of ten fungal genera were isolated from diseased grape berries and stems collected from a vineyard. The isolated fungi included the grape pathogens, Greeneria uvicola and Colletotrichum sp. Secondary grape and human pathogens isolated included Alternaria spp., Aspergillus spp., Cladosporium cladosporioides, and two Penicillium spp. Non-pathogens of grapes found were Curvularia brachyspora, Epicoccum purpurescens, Nigrospora sphaerica, and Trichoderma sp. CAY-1, a fungicidal saponin found in cayenne pepper and paprika, was inhibitory and/or lethal, in vitro, for the germinating conidia of G. uvicola, Colletotrichum sp., C. cladosporioides, the two Penicillium, and the Aspergillus species isolates, N. sphaericus and Trichoderma sp., at concentrations equal to or greater than 7.5 uM. Minimum Inhibitory Concentration assays results were higher. Results show CAY-1 is inhibitory and/or lethal against several primary and secondary grape pathogens of agricultural and medical importance.