What's going on with these berries?

[David Engel]

Hi All,

I'm about a week (or so) away from harvest. We have had a ton of rain lately and when I went out today to check on things found this. It's only on 2 clusters. The 3rd picture is a cluster which represents about all others on all the vines. What do you think?

 

[Rice_Guy]

Looks like those clusters picked up water and burst. Then spoilage set in.
I would consider picking sooner.

 

[VinesnBines]

Looks like those clusters picked up water and burst. Then spoilage set in.
I would consider picking sooner.

I vote for harvest immediately. Don’t lose more grapes.

 

[Cynewulf]

Agree with Rice and Vines. The wounded berries look like they may have picked up sour rot. I had a lot on my Marquette this year, which has thin skins. Much less on my Cab Franc.

 

[countygrapeguy]

I had that last year and assumed splitting due to rain, but then had the same this year in dry weather and have pinned the problem on wasps/hornets. I've watched a number of bald faced hornets crawling through the clusters, and they'll cut right through the skin in a semi-circle around the berry.

 

[David Engel]

Have seen no flying critters under the netting. Harvesting tomorrow.

 

[keverman]

Agree with sour rot, and it's only going to spread from here. Could be the rain burst them, or it's creatures, but either way now little critters will start picking and spreading the bacteria. Harvest. I'm in Ohio and have no choice but to use bee netting the minute I start to see them show up. Wasps and the previously mentioned bald-faced hornets, those guys are the worst.

 

[Rice_Guy]

Agree with sour rot

The first question is can you taste it already?
the second note is if you know you are starting with a high load of spoilage organisms, do you want to do a double dose 100ppm of SO2