Anthracnose is caused by Pseudopeziza ribis and the symptoms are spots on the lower leaves, which then drop. The circular, brown to black spots also form on the fruit and leaf stems. No chemical control is listed.
Dieback or cane blight attacks cause wilting. Prune out and destroy infected tips. No chemical control is listed.
In rainy seasons, leaf spots cause premature defoliation. Use basic copper sulfate.