Anyone Know What This Is ?

[Nyboy]

This is a leaf on a Reliance grape vine, I have 4 vines only 1 leaf has this. Reliance is suppose to be disease resistant grape

 

[Ridgerunner]

This one takes a long time to load.

http://www5.agr.gc.ca/resources/prod/doc/sci/pub/pdf/id_guide_major_diseases_grapes_e.pdf

Powdery or Downy Mildew – Page 9 & 16

Disease resistance does not mean disease free.

 

[Nyboy]

The link didnt open for me, I did look up both powdery and downy color wrong. Can grapes get apple ceder rust ? Redish brown group of spots raised up on back side of leaf

 

[so lucky]

That might be some kind of bug, that laid eggs in the raised up area. If you have a microscope, you may be able to cut the bump open and look at it, possibly seeing an egg or larvae. If this is what you have, and only one leaf has it, just burn the leaf and count your blessings.

 

[lesa]

I see those on my wild grapes all the time. No idea what they are- but they don't seem to hurt anything. Not all the leaves are affected. Good luck!

 

[Nyboy]

Only 1 leaf and only 1 side of leaf. I pulled it off was wondering what it is. Will keep eye on vines to see if any more leaves get it.