We are a month in to the new year and I just wanted to remind everyone that if you have not already done so, it is time to start thinking about a delayed-dormant application of horticultural oil for scale insect management. The above 50°F weather makes for a lovely day, but the scale insects enjoy it too, becoming developmentally active above 51°F. That means it is a good time to nip these guys in the bud.
For delayed dormant timing, apply dormant horticultural oil at a rate of 0.75-1.5% oil to water. It is recommended to apply the oil:water mixture at high gallonage in order to maximize coverage. As you have probably heard me say over and over again, if you are applying the delayed-dormant application to pre-pruned trees, then it is important to aim for 150-200 gal/acre to get effective coverage, especially in areas with a history of scale pressure. If the trees have already been pruned, then lowering the rate down to 100 gal/acre seems to be effective.
Additionally, combining an insect grower regulator, such as Centaur or Esteem with the oil can enhance the control of the scale. Similarly, combining Venerate with the delayed-dormant oil application has also shown to significantly suppress scale numbers compared to oil alone.
Alternatively, incorporating chlorpyrifos with the oil application provide suppression of scale insects as well as lesser peachtree borer when applied at bud swell.
For more information, please see the updated peach management guides
Note, do not apply oil sprays within 2 weeks of (before or after) making a spray that contains sulfur.
Speaking of the management guides, the 2021 Southeastern Peach, Nectarine, and Plum Pest Management and Culture Guides have been printed and will hopefully be available soon!
In the mean time, the digital (PDF) version can be accessed at any time at the link below.
https://extension.uga.edu/publications/detail.html?number=b1171
Here’s to a great 2021 season!!
