Wettable sulfur applied at three to ten pounds per acre in at least ten gallons of water per acre also will protect the crop from serious loss. It is very important that the sulfur application be made with an adequate volume of water, or its effectiveness will be reduced. Often, if the sulfur application is to be made by an aerial applicator, less water is applied. If disease onset occurs early in the season, more than one application of sulfur may be required. Usually the second sulfur application is made three to four weeks after the first.
Sulfur controls the disease by dramatically lowering the rate of disease spread.
The sulfur will decrease the production of secondary conidia and will protect non-infected leaf surfaces from becoming infected. The non-infected tissues will remain healthy. Foliar sprays of triadimefon are also used for powdery mildew control. Triadimefon is a triazole fungicide and is classed as a steroid demethylation inhibitor. The fungicide provides systematic control of powdery mildew.