Spots on blackberry leaves
We have been seeing these reddish brown spots on the leaves of some of our blackberry plants. The edges of the leaves get brown and dry as well. What is this and how do we correct it? We have been using a 3 in 1 organic fungicide/insecticide spray every week for the past few weeks. Temperatures have been very hot and humid for the last month. Blackberries are watered with drip irrigation but perhaps not enough.
This sounds like Blackberry Calico Virus.
This link will give you more information.