The grapes are growing well, but as usual, they have developed black spots on them. blogs.cornell.edu/grapes/ipm/diseases/grape-disease-control-spring-2021/ tells me If the early season diseases were competing in the Olympics, Black Rot would easily claim a spot on the podium. Black rot thrives in humid climates and is prevalent in the eastern industry. Under my conditions, berries are highly susceptible to black rot from cap fall until 3-4 weeks (Concord/Niagara) or 4-5 weeks (V. vinifera) later. After this point the berries begin to lose susceptibility and will become resistant/immune after an additional 2 weeks. While black rot can be spread by spores blowing in from distant infections on wild grapevines, it is most frequently started from mummified berries left by the previous year’s infections, making vineyard sanitation CRITICAL for effective black rot management (see subsequent section on cultural management for moProtectants mancozeb and ziram have been shown to provide effective control. Captan is less effective but will provide some control. Copper only provides slight control. Unlike powdery and downy mildew, the DMIs and strobilurins will generally provide strong black rot control. High efficacy products include Abound, Aprovia Topre detail). Infection will spread from leaves to the fruit and can result in complete crop loss under severe conditions.
However, the above remedy for my problem is not he answer for me. I grow fruit and vegetables at home to avoid chemical application. I would rather let the grapes go to the birds rather than applying chemicals. Usually I can harvest a few of the grapes that are not exhibiting these issues. I feel success in life and relationships often requires sacrifice from all equally in order to find balance. We all have to determine to what degree we are willing to make sacrifice and where we personally desire to draw our line in the sand relative to such.In this case, I am willing to succumb to the loss of produce rather than ingest the chemicals. You have to decide where you stand.