Neem oil spray for powdery mildew
Hi. I am wondering when I can spray dormant fruit trees that had powdery mildew last year. The package directions state not to spray when temps are below 40 degrees. Next week temps should be in the 50's but still cold over night. Can I spray yet? I want to spray before buds open, correct?. Thank you.
Washoe County Nevada
Depending on the product that you are using right now it would not be ideal as there are multiple storms in the forecast for the next week. In general heavy dormant oils are typically used in February before bud break and primarily for over wintering insects. Fungicides or copper sprays need to be sprayed separately from oil sprays unless the label state specifically they can be combined.
I have attached a few information sheets to help you with understanding the cycle of powdery mildew and the options available for controls.