The resulting protocol takes less than half an hour to perform, requires equipment that costs about $50, uses consumables that cost only about $5 per analysis and could save growers thousands of dollars, says Wilcox.

"Elemental sulfur generally costs $10-$20 per acre less than other powdery mildew controls," said Wilcox. "A grower with 50 acres of wine grapes who is able to use elemental sulfur in place of more expensive sprays five times during the growing season could realize savings of several thousands of dollars."

Kwasniewski found that the method works just as well on drywall, which can also be contaminated with elemental sulfur. Microbial digestion of sulfur has been suggested as a source of rotten egg smell and corroded pipes in homes afflicted by "Chinese drywall syndrome."

Sample sulfur detection kits have been distributed to interested growers and winemakers across New York and extension agents in Oregon, Ohio, Virginia and North Carolina for testing during the coming harvest.

The project was funded by the Canandaigua Wine Endowment Fund, federal formula funds provided to state land grant universities in support of agricultural research and the New York State Department of Agriculture and Markets.