Yuck!

I've noticed that portions of the vineyard sometimes develop odd-looking leaves, and often I chalk it up to lack of water, or nutrients.

BUT, there's one part of the vineyard (mid-downhill side of row 7) that for TWO years in a row now have looked like they got severely burned leaves early in the season.  Weird part is that later in the season, the new growth looks nice & green & healthy.  But year-over-year trends make me nervous.

There are 3 things I've noticed:
(a) the burning leaf look
(b) black tar-like gunk on the shoots (markedly different than PM indicators)
(c) hard to see here, but some leaves off of this shoot are very small & crinkley - maybe 10% of 'em.

Given these symptoms, my worst fear is that this is Eutypa Dieback, but symptoms look different, and in pruning I didn't notice any of the traditional wedge-shaped discoloration in wood.

A trusty guide of messed-up leaves points to possibly Potassium deficiency, here's an image from Virginia that looks kinda similar and indicates the burning appears on mid-shoot leaves.  Overall vineyard checked out as having enough potassium, but could be this chunk is low?  Hmm.

Pierce's Disease would be bad.   Leaves aren't dropping at the petiole, however - in fact the attachment is pretty strong.

A new one I've not heard of - Esca, or grape measels?!? So far this is the winner in terms of fit. In terms of treatment yuck.