pruning Concord grape vine
Hi, Several years ago I moved inherited a garden with an established concord grape vine. The first year I did no pruning and had a bumper crop of ripe grapes. The next 2 years I pruned aggressively and grapes developed but did not ripen. Last year I discovered black rot mold and based on UMD CE's advice (Question:406857) I began spraying every few weeks. I also cut back leaves so grapes would get sun, but they still didn't ripen (only a few on each bunch). I just pruned the vine based on what I learned on line (choosing 10 healthy looking 1 year old spurs that are pencil thick. Should I spray the vine just to make sure there are no mites or mold that survived the winter? Attached are two photos.
District of Columbia County District of Columbia
Concord grapes do have the reputation of not performing well, which includes not uniformly ripening, in the warmer areas of our region. Maybe try pruning it less severely this season to see if that makes a difference this year. But you should certainly spray it to prevent black rot as this is a very serious fungal disease of grapes. Please see the following information on our website, http://extension.umd.edu/hgic/diseases-grapes