California winegrape growers should return to the time-tested practice of applying sulfur to control powdery mildew disease, according to Doug Gubler, a Cooperative Extension plant pathologist at UC Davis. In the 1970s, growers abandoned sulfur dusting because it required frequent applications and almost perfect weather conditions. However, new sulfurs and sulfur sprays that are effective even when wet and are easier to apply now allow growers more alternatives for controlling the disease, says Gubler.