I wanted to post this a while back but never had my camera on hand for these ones. I had noticed a few issues and am deciding a diagnosis, check it out:
This was seen on the marechal foch and so far only seen on very few plants on the foch. I am wondering if it is phylloxera or not, the characteristic leaf galls as seen is what made me choose. We did see a larvae on the leaf but without a microscope it would be difficult to describe or identify.
This picture here is of a Baco Noir leaf, and is not an uncommon site in the vineyard. Is it a deficiency symptom or is it grape phomopsis? Reading up further about phomopsis I feel I should go take a peek at the green shoots and this fall when we are pruning keep an eye on the stems. I though i had read that it has black spots with yellow halo’s around them and invades the veins first, thought this picture showed it very well, but I am still undecided as to what it is or not.
A book that is on my wish list now is the compendium of grape diseases, sounds like a very useful tool. A book I had just ordered today, and sounds like it was too good to pass up was publication 360, Fruit production recommendations.
Thats all for now, yet even more questions pop up, great for learning!
Following up on these two issues, the first one IS phylloxera, not good, however it was suggested to not panic too much, just cut the infected areas off and monitor next season.
Phomopsis, still deciding, but the more i read, the more it fits the bill. Looks like we may have to gear up for a spray next season.