Black rot is probably the “Achilles heel” for organic grape production in the East. In the only good trial that we’ve run with copper, it provided 40% disease control when applied at 2-week intervals, versus essentially 100% control with Nova. To try to avoid this, implement a rigorous program to remove mummies during pruning, and spray copper once a week throughout much of the growing season. This was hard on some of the hybrid vines and runs counter to the thinking of many with a “sustainable” orientation (after all, copper is an element and doesn’t break down into anything else, so it stays in the soil forever), but it did control the disease in an organically acceptable manner. Limit inoculum within the vineyard. Ideally, this would include removing or burying any mummies that you might encounter at the site. All mummified clusters should be removed from the trellis during pruning and from 2 to 6 weeks after cap fall and prune out any affected clusters before they allow the disease to spread, all the better (spores for disease spread are dispersed by rain primarily within the canopy, so should pose little risk of causing new infections if said clusters are simply dropped to the ground).