It’s not on the shelf yet, but UC Plant Pathologist Doug Gubler and other researchers are tweaking the popular grape powdery mildew index to help growers and PCAs cope with disease threats.

Gubler is taking a closer look at the role high temperatures play in sporulation, germination and lesion expansion.

“Once we get fine tuning done on the model, I think it will benefit growers a great deal,” he says.“We still have this year’s work to do on the field portion, so we won't actually change anything for over a year from now.”

So far this season, powdery mildew has not been a problem, Gubler says. But, that could change rapidly. “We suspect that the recent rains we had has released ascospores. We’ll soon see.”