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Texas
Agriculture Archive
March 5, 2004
Peach insect treatment
timing critical
By Robert Burns
Texas Cooperative Extension
Peach growers should be wary of possible increased pest problems this season, said an entomologist with Texas Cooperative Extension.
"The buds are still tight, and it's not too late to do preventive spraying," said. Dr. James Robinson, one of the featured speakers at the Annual East Texas Fruit & Vegetable Conference, held Feb. 17 at the Tyler Rose Garden Center, Tyler.
Based on the accumulated chilling hours and barring a late freeze such as happened last year, growers can expect a good crop this year, Robinson said.
Peach trees need a certain number of hours of temperatures in the range of 32 to 45 degrees, called "chilling hours." The tree goes through hormonal changes leading it to come out of winter dormancy and start producing complete flowers and leaves. Different peach tree varieties need varying amounts of chilling hours.
Last year's devastating late freeze caused many growers to discontinue their regular spraying schedule. This set the stage for increased pressure from both diseases and insect pests. This doesn't need to be discouraging news, as so far a good crop is possible, but it does require extra vigilance for insect pest problems less they get out of hand, Robinson said.
Peaches in February are usually in their dormant state, but subject to damage from scale insects and spider mites. Two applications of superior oil at 10- to 14-day intervals works best, Robinson said. The re-entry period for superior oil—the time that must pass after spraying before it's safe to work in the orchard—is only 12 hours, but this doesn't mean it's a good idea to procrastinate, Robinson said.
"Temperatures that are consistent and cool are optimal for oil application. Avoid spraying when either temperatures are expected to drop drop near freezing or unseasonably warm," he said.
After petals fall and the small fruit begins to form, plant bugs, oriental fruit moth and plum curculio become the primary concern. Spider mites may continue to be a problem throughout the year, and can cause serious defoliation. Infestations are most likely during dry years.
"Don't wait until harvest to control mites. Not because of re-entry delays but because of having to delay harvest for as much as 14 days after treatment with some products," Robinson said.
There are numerous products and treatment strategies for the various insects, making choices complicated at times. Robinson has made a slide show available on the Internet outlining the various products, the timing of their application, and under what weather conditions or growth stages each is likely to be most effective. To view the slide show go to http://overton.tamu.edu/peaches/peach+insects.htm.
Commercial growers and those with home orchards can also find booklets available on peach insect control at their county Extension office. For commercial growers, the recommended publication is the "2004 Southwestern Peach, Nectarine and Plum Pest Management and Culture Guide." For home orchards, Robinson recommended the "Homeowners Fruit and Nut Spray Guide."
Robinson has been an Extension entomologist for more than 25 years, most of which he has spent in East Texas. He retires in late February.
"We're going to really miss him. He's always been ready to help agents and growers alike," said Keith Hansen, county Extension agent-horticulture, Smith County.
