Yipes!

[Smiles Jr.]

Oh My! What do I do? These are supposed to be Tickled Pink grapes. I have never grown grapes before. I inherited Dad's grape arbors and I don't know what to do. I do know that this particular row is only three years old and this would be the first year for harvest. There are 27 plants in this row and 21 plants show this problem. I just discovered it this morning during my daily dawn walk through the farm.

Could it be too much rain? Disease? Bugs? Blight?

 

[Smart Red]

I believe that is bug damage. You should be able to see small (scarred over) spots where eggs were inserted. As the bug grows it eats from the inside out and can cause the fruit to "ripen" in the damaged area.

 

[majorcatfish]

Could be black rot if so you need to start spraying copper
And cut out all the infected areas it's a witch to get rid of

 

[Chickie'sMomaInNH]

looks like black rot. some grapes are prone to issues with it. i agree with Major, cut off those affected areas and spray with fungicide/copper. you might want to give them a rest this year and hope next year they don't show signs of this.