Peppers To Die For: These "Hot" Plants Could Protect Strawberries—and More

What's the connection between fiery cayenne peppers that give heat to Creole cuisine, and the sweet, juicy strawberries of summertime?

A potent substance found in cayenne peppers may someday be used by growers to battle the costly molds that can spoil strawberry, blueberry and grape crops. Last year, Agricultural Research Service scientists received a patent for a novel fungicide, called CAY-1, which is derived from cayenne peppers. Now they are looking to find out how well its fungal-fighting powers work on strawberry molds.

Anthony De Lucca, a microbiologist at ARS' Southern Regional Research Center in New Orleans, La., teamed up with plant pathologists David Wedge at ARS' Natural Products Utilization Research Unit in Oxford, Miss., and Barbara Smith at the agency's Small Fruit Research Station, Poplarville, Miss., to test CAY-1's efficacy on fungi that afflict strawberries. With a year of promising plant and laboratory results behind them, the scientists are conducting greenhouse studies that may pave the way to CAY-1's commercial availability.

De Lucca isolated the CAY-1 saponin in his lab five years ago, while searching for natural compounds to shield crops from infesting fungi. Found widely in plants, saponins have detergent properties, causing them to foam when shaken with water. Like laundry detergent that works by penetrating a fabric's fiber, the cayenne saponin breaches fungal cells by forming little holes along cell membranes.

CAY-1 has been shown to be active at low levels against Collectotrichum and Phomopsis, two economically important fungal pathogens affecting strawberries and other small fruits. In strawberries, Phomopsis causes serious leaf blight and fruit disease.

But CAY-1's potential doesn't stop at crops. This powerful natural derivative could support a range of applications, says De Lucca. Possible uses include a mosquito larvacide, a molluscicide to rein in the prolific zebra mussel that's fouling water supplies in the Great Lakes, and a mildew-zapping bathroom product.

Already attracting industry attention, CAY-1's antifungal activity is the focus of studies by several commercial companies. ARS is providing the cooperators with the cayenne extract.

ARS is USDA's chief scientific research agency.