It’s still a little early for peach twig borer (PTB) populations to be active. “Typically, the pest emerges in early bloom. It begins to come out of the hibernacula and moves up to the tips of the shoots where it bores in, and that’s where most of the damage is caused,” Valent Field Market Development Representative Tino Lopez said.
Growers have to use products that are bee-friendly during bloom. Lopez said that means products that are Bacillus thuringiensis-based, like Valent’s DiPel Bt. Some growers will consider another strategy toward the end of this month, however, that avoids direct timing with bee activity. “Because there are no bees present at that time, often times we will use a program like Seize to control scale, and at the same time we get suppression of the hibernacla and any that we get in contact with,” he said. “Keep in mind it’s a little harder to contact because they are in the hibernacula, but we still are able to get a certain percentage of them.”
Although PTB hasn’t been a major issue recently, Lopez said it’s well worth it to keep an eye on potential, especially in the valleys of the state. “It depends on the area. There are some areas, like down south, where it’s not a problem. But a lot of our problem is seen in the Northern San Joaquin Valley and Sacramento Valley,” he said. “The damage can be severe, particularly on young trees, because it’ll kill a lot of the shoot growth. You will have to prune out a lot of material, and it will slow down the development of that tree which delays when it can begin production.”