Firmness and Splitting in Grapes

This year I harvested several different cultivars of grapes for the purpose of seeing what kind of firmness and splitting data I could get.  It was not a true study, just a quick “look-see” to get an idea of how it would work.  Below is some of the observations I was able to get (will help from Dr. Donna Shaw and Lavonne Stringer). Brix (sugar levels) were recorded first to see how high they were at harvest.  Nine cultivars were chosen — Blanc du bois, Champanel, Cimarron, Conquistador, FAMU99, MidSouth, Miss blanc, Victoria Red, and Villard blanc.  As you can see below, sugar levels were low for most, although these were only samples and the entire vine was not necessarily harvested.

Brix measurements of 9 grape cultivars

Brix measurements of 9 grape cultivars.

Individual berries were then tested for firmness, as seen below.  In most cases, the lower the brix, the better the firmness. This is not surprising as unripe berries would be expected to be firmer.  One big exception was Conquistador which was the firmest berry by far, even at nearly 18 brix.

Firmness of nine grape cultivars.

Firmness of nine grape cultivars.

Finally we looked at how the berries split if exposed to water. We did this in two ways, individual berries and also as whole clusters. The results were almost the same both ways but I will show both. MidSouth, FAMU99, and Conquistador showed a tendency to split when submerged in water overnight. So in this case firmness did not seem to be strongly tied to splitting tendency.

Individual berry splitting of nine grape cultivars.

Percentage of individual berry splitting of nine grape cultivars.

Things were mostly the same when whole clusters were submerged, although there was a little more on Blanc du bois. The difference was small though and with replication and a larger sample size may not be significantly different.

Percentage of berries from whole clusters that split from nine grape cultivars.

Percentage of berries from whole clusters that split from nine grape cultivars.

I was surprised by the lack of splitting from Victoria red. It has what I would characterize as a thinner skin than most of these cultivars, yet it did not split at all. A good thing to know.  Obviously Conquistador has a tendency to split, as ~50% of exposed berries did just that.  Next year we will give it another go-round and see what happens then.

Advertisements

2 responses

  1. Eric,

    I noticed you have MidSouth and MissBlanc in your study – do you have or want MissBlue to add to your vineyard? I have several rooted cuttings of MissBlue (and the other two also) if you’re interested. Also, I was wondering if I could get some cuttings of Champanel for my personal vineyard – we had it here at the station in Hammond several years ago, but we lost it and I haven’t been able to find it again. Sadly, we no longer have any grape vineyard, it was dismantled for “progress”.

    Hope all is well at Poplarville,

    Joey Quebedeaux

    • Joey:
      I do not have Miss Blue but would like to have a vine or two. Yes, you can get some Champanel from me this winter. Just remind me. Hope to see you in October at the Ornamental Field Day if not before.
      Eric

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s