Hi,

I live in Quebec near Montreal. I have a 9 year old grape vine that was pruned for the first time last year. I removed about 50-60% of the vine's old wood.

Normally, the vine would break from dormancy and leaves would show up on all branches in May every year. For the first time, last year, before I pruned the vine (I pruned it in June) all buds did not open up. I knew there was something wrong, but I ignored it thinking it was due to the cold weather. Finally, in mid-June, there was some activity and new growth, but the young leaves looked burned and had back spots on them (similar to the pictures I've posted). Some of the leaves looked healthy, but about 50-60% of them looked abnormal. A few of the new branches did not survive and died.

By mid July, I sprayed MiracleGro on the leaves, and the vine was growing well and the new leaves for the most part were healthy (I read that black rot disease stops spreading in mid-summer). However, almost no fruit was produced by the end of the summer, which is unusual.

I thought I damaged or did something to the tree due to pruning, but I do remember that usually in May, the vine would be full of leaves. That was not the case before I pruned it in June 2014.

I was hoping that the issue would go away this year, but no, it's back. A few leaves in May, many of last year's new wood looks dead (we had an extremely harsh winter, but other vines in my area appear fine). There is a few grape fruits, maybe I'll have some fruits this year. 70% of the leaves look like the pictures I've posted.

I have not yet used any fungicide, but I think I have Black Rot. Can you confirm it? Also, if I were to cut the vine at the lower trunk level and remove all branches and leaves, would it kill the vine or would new growth emerge? Would it still be infected?