Hello!

Our fruit and nut tree specialist states:

Dormant oil sprays are primarily made to control white peach scale, and may provide other sanitizing benefits. Timing may be from late December through late February, but should be applied prior to bud activity. Trees should be sprayed copiously for oils to provide expected benefits. The type of oil to use is a petroleum-based horticultural oil labeled for fruit tree use. They may be called 'dormant oil'. Application is generally 1-3 Oz per gallon of water. Always follow label directions for the product being used.. Additional publications for peaches and other fruits can be found at http://aggie-horticulture.tamu.edu/fruit-nut

I've also found these links that provide some great information:
ENTO-087-Insect-and-Disease-Pess-of-Peach-Plums.pdf (agrilife.org)
Fruit and Nut Spray Guide (agrilife.org)

Thanks for submitting a question!