I am a little late with the post for this year, but with the cooler temperature this spring, the scale insects have been slow to develop as well. However, with the warmer temperatures, the scale will begin to develop, so if you haven’t gotten out your delayed-dormant spray yet, there is still time.
For delayed dormant timing, apply dormant horticultural oil at a rate of 1.5-2% 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. Increasing the rate to 3% oil at 100 gal/acre may also achieve effective coverage.
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.
Also, note that after last year’s court order, chlorpyrifos tolerances are now in effect and thus can be used again in accordance to the registered labels (more info here and here). As used in the past, chlorpyrifos may help suppress both scale insects and borers when applied with oil at bud swell.
Also note, do not apply oil sprays within 2 weeks of (before or after) making a spray that contains sulfur.
For more information and additional management options, please see the peach management guides:
Please note that the 2025 version has not been release online, but will hopefully be posted soon.
Here’s to a great 2025 season!!
