A Handful of Grapes
This year's grape harvest:
These are our Concords. Not all of of vines are bearing yet, but the Concords looked like they were going to do pretty well this year. But as September arrived, it became clear that we had a problem:
See how we're missing a lot of grapes? They are on the ground, shriveled up. A bunch of the ones that are left have shriveled also. The handful of good ones in the first photo were about our whole harvest.
(I should note that they were completely delicious — sweet and so grapey that I finally understand what the flavor "purple" in medicine and candy is based on. Concord grapes have really excellent flavor. These plants have outdone all our others in vigor of growth this year also.)
All of our grapes that are bearing are having a problem with the shriveled, unevenly-ripening fruit, and their leaves are turning brown and dying back as well:
As near as I can tell, the problem here is black rot. This is a fungus that spreads in warm, wet weather (like we had all through July), and wrecks the fruit. The good news is that it's not always bad, and drier weather in the future should help give us a better growing season (for grapes, at least, if not for everything else). The bad news is that it's hard to control on the East coast, and hard to control with organic methods.
Ohio State has some detailed guidelines for organic growers, and it looks like sanitation is the best approach. So I spent this morning clipping off dead and dying leaves and mummified clusters of grapes. I can't put them in the compost pile, so they got tossed out on the hill behind the fence. I also raked up all the debris under the plants and threw it away.
When we do our dormant pruning in the spring we'll have to triple-check for any diseased branches (with black lesions) and fruit mummies still hanging around to get rid of them. We should also cultivate the soil to bury any infected fallen fruit. I'm thinking a rock mulch could help here as well to prevent splash-up (of germy soil) on the lowest leaves when it rains.
If we had been paying closer (or any) attention to the grapes earlier in the summer, we might have been able to remove some diseased parts back in July and kept this under better control. As it stands, we have a couple grape vines that look pretty terrible, with barely any leaves left at all. Hopefully they bounce back next year with a little less abject neglect on our part.