Question About a grape problem 8-11-14
Hi, Last year my wife and I planted two grape vines in our backyard, one is a Concord grape, the other a Reisling. Both years the grapes are dying back before they become ripe. Last year we did nothing and none of the grapes survived. This year we tried several things and the Concord grapes seem to be holding up, but the Reisling grapes have pretty much all died back. We are hoping someone might be able to give us some idea of what is going on and if there is anything we can do to get some healthy, mature grapes - if not this year, then possibly next year and the following years. This year both grape vines have been treated with: Daconil fungicide and disease control (sprayed three times beginning with leaf break in early spring), hydrated lime (to increase available calcium), and Imidacloprid (Bayer systemic insect control). A few recent pictures are enclosed. Any help you can give will be greatly appreciated.
Montgomery County Pennsylvania
The picture shows that the problem on your grape clusters is caused by the disease known as black rot. The Riesling vine probably died this year due to the extreme cold temperatures this past winter. This was a common problem this season for Vitis vinifera varieties such as Riesling.
Three sites below provide information for grapes concerning insect and disease identification and management, cultural practices and selection of varieties.
Penn State’s Fruit Production for the Home Gardener http://agsci.psu.edu/fphg
Pest Control in Small Vineyards - http://web2.msue.msu.edu/bulletins/Bulletin/PDF/E2698.pdf
Cornell Guide to Growing Fruit at Home http://ecommons.library.cornell.edu/bitstream/1813/67/2/Cornell_Guide_to_Growing_Fruit.pdf