Low level leaf death (not frost)

[spaniel]

Yesterday I realized that the shorter (less than foot tall) Marquette I planted last year had a lot of nasty looking blackish and dying leaves. The taller vines trained up on the poles seemed perfectly fine. I assumed I had screwed up and had drift onto them from glyphosate/simazine mixture I had sprayed directly onto ground level a distance away, although with the wind/spray level it should not have been an issue.

Today I noticed that vines in a different part of the property which were of similar stature, but could have had absolutely no exposure to spray, exhibited similar symptoms.

I have not seen this before. All I can think of is that we had several days of constant rain recently. Can "wet feet" cause vines to do this? I'm curious why height of the foliage above the ground is clearly related to the effect. The vines were not flooded but it is certainly not what I would consider well-drained soil (you do with what you have to work with, never been an issue before).

 

[Deezil]

Has it been relatively warm as well as wet? Wet, warm, and close to the ground is the perfect conditions for mold/mildew.. Been much wind blowing? If not, it's even more ideal for those nasties..

The higher the foliage is from the ground, the better the air movement and the farther away the leaves (which perspire/sweat on their own) are from the ever-present moisture in the soil... Keeping them up off the ground gives the leaves a 'dry period' instead of being perpetually damp... It's the continually-damp part that gets the mold/mildew going; the mold is pretty much always present everywhere, but when the conditions are right, it rears its ugly head..

 

[spaniel]

That makes sense, don't know why mildew didn't occur to me. I wouldn't say conditions were perfectly ideal but we had a day when I could have seen that happening.