San Jose Scale Management: Horticultural Oil Applications Key for Peach Producers

Jim Rogers Disease, Georgia, Peaches

By Clint Thompson

Horticultural oil applications are essential this winter for peach producers hoping to manage San Jose scale insects.

San Jose Scale
San Jose scale is an insect pest that damages fruit, like this peach, and can eventually kill fruit trees. Photo Credit ~ UGA CAES

Brett Blaauw, assistant professor at the University of Georgia (UGA) College of Agricultural and Environmental Sciences, says the warm winter conditions across Southeast aid the scale’s development. Growers can ill-afford to miss an application.

“Getting ready for their dormant applications of oil is key for pest management. They’re going to want to do at least two applications, one they might have already done. But if they haven’t done their first application, getting out their first dormant application of horticultural oil is very important,” Blaauw said, “then getting ready for their delayed dormant application of horticultural oil, which will be coming up in the next month or so as the trees start to reach bud break.

“That’s really our first defense against San Jose scale coming up in the season. A good application of oils now can really help keep the populations low during the season, hopefully, staving off any additional insecticides.”

San Jose scale is a tiny insect that has a waxy coating. It covers and protects the whole body of the insect from the environment and other predatory insects. Unfortunately, it protects them from insecticides.

“I think this year a real good coverage of oils is going to be key, making sure to get a high volume of oil plus water. We’re looking at 150 to 200 gallons per acre to get that good coverage. This year, with the warm winter that we’ve had so far, it is allowing those scales to continue to develop and reproduce. I think we’re going to start off the season with pretty high populations. We want to hit them hard now while we can.”