Thornless blackberry, appx 9 yrs old. First occurred 3 yrs ago on limited...
Thornless blackberry, appx 9 yrs old. First occurred 3 yrs ago on limited canes. Worse the 2nd yr and now appearing on all leaves including lateral growth canes. Canes are about 1-1/2' tall at this point. Full sun, most all day. Sandy soil. What is happening and is there a cure? Thank you.
Sussex County Delaware
Our fruit specialist and our pathologist concur that there is no evidence of disease, but that the white spots are most likely the result of environmental factors such as cold damage or even sand particles being blown across the surface of the leaves. The fact that this is the third year suggests a pattern of some kind, but we are not able to discern it. Are there any other cultural factors that could happen three years in a row? Do you spray the plants with any chemicals? If wind is a factor, perhaps you could erect a wind barrier on the windward side of the bed.