What did you use to clear the area around your vines? Did you hand pull the weeds or use a hoe or possibly apply a weed and feed lawn product? The vines look like they have an herbicide damage. If you sprayed Roundup around them and touched the leaves or young green shoots, the spray can cause that type damage. It can also be 2,4-D damage (herbicide) from applying a weed-and-feed type lawn product. The vines will hopefully grow out of it, but it sets them back a bit.
Even though the other rows don't look like that doesn't rule it out. SOme varieties are more susceptible to 2,4-D damage than others.
I said the same thing over on the other site were you posted pictures too. Grapeman does a far better job at explaining things though. I can add that I have had 2,4-d damage to my vines (neighbors lawn service carelessness). The vines did survive but were set back from the rest of the vines regarding how quickly they got established.
I holed around them then I was told that I could sprinkle Preen around them and it wouldn't hurt them and I did make sure that I didn't get any on the leave when I did it. Thanks for the replys I guess I will not do that again.
I don't know exactly which Preen product you used but here's a link to the msds sheets on ALL the Preen products. The active ingredients range from 2,4-D and dicamba all the way down to corn gluten meal. It depends on which one of their products you used as to it's make up.
farming hubby is having trouble getting his thoughts into words...this is the best i could do, lol...
"maybe the rain caused a concentration or pooling of the chemicals at the base of the plant"
either herbicide or concentration of nutrients? just some thoughts...
have you asked your county extension agent?