My Vines’ leaves are turning red/brown! Help!

[Mgoldy]

I’ve been making wine from kits for a few years, and going to try my own grapes this year for the first time.
My vines’ leaves are turning red/brown. What is happening?! Help!

 

[NorCal]

There are a lot of mineral deficiencies that can cause red color in leaves. I have a few vines with red blotch, but I don’t think that is what you have.

 

[Mgoldy]

Thanks NorCal! I’m actually in NorCal - Red Bluff (near Redding).

 

[Mgoldy]

How can I determine which mineral deficiencies I have, or is there a “general” additive I can buy to apply?

 

[Rocktop]

Looks almost lick some black rot on the grapes but usually presents as spots on the leaves .

 

[Rocktop]

Your local ag extension or local private firms will be able to test for you, get your soil tested and test your leaves. This will tell you if the vine is currently deficient and what soil amendments you need for the future.
‘The ag extension or others in your area will be able to give you a good idea of what sprays and frequency you need to control the mildews and diseases in your area.

RT

 

[NorCal]

UCD has a lab. I’ll take a pic of a vine with red blotch in my vineyard, which is what is common when Ive seen discoloration like this. Yours looks different to me though.

 

[NorCal]

I have 3 vines with this, which I attribute to red blotch.

 

[skatefriday]

Thanks NorCal! I’m actually in NorCal - Red Bluff (near Redding).

There's a Fruit Growers Lab in Chico that will do leaf/petiole and soil analysis for you. It's about $60 each. I think it's worth it because pretty much _everything_ causes red chlorosis in red varieties. So the analysis, as long as your problem is not viral, which is a different, much more expensive test, you aren't guessing.

The report ends up looking like this...

https://www.winemakingtalk.com/threads/help-me-interpret-my-lab-results.77845/
Chico is not too far from Redding. I drive about an hour each way to get to my local FGL. Good people there also.

As an aside, looking at your photo, I was advised by the nursery I bought my vines from, to remove all of the clusters that formed the second year. So sad...

Good luck. I'm in my second year. Table, not wine, grapes and have found them to be extremely temperamental little buggers.

 

[Mgoldy]

There's a Fruit Growers Lab in Chico that will do leaf/petiole and soil analysis for you. It's about $60 each. I think it's worth it because pretty much _everything_ causes red chlorosis in red varieties. So the analysis, as long as your problem is not viral, which is a different, much more expensive test, you aren't guessing.

The report ends up looking like this...

https://www.winemakingtalk.com/threads/help-me-interpret-my-lab-results.77845/
Chico is not too far from Redding. I drive about an hour each way to get to my local FGL. Good people there also.

As an aside, looking at your photo, I was advised by the nursery I bought my vines from, to remove all of the clusters that formed the second year. So sad...

Good luck. I'm in my second year. Table, not wine, grapes and have found them to be extremely temperamental little buggers.

Thanks for the location of a test lab, Skate! I’m about 50 mins from Chico! Thanks also for the sample test report. I’ll definitely take some soil and leaves in for testing.

 

[vtoddw]

I’ve been making wine from kits for a few years, and going to try my own grapes this year for the first time.
My vines’ leaves are turning red/brown. What is happening?! Help!

That burning and those shriveling berries looks like multiple issues I've had in the past. The berries look like they were cooked over a high temperatures spanning a day or two. I used to just assume I could water my vines the same amount at the same interval every week and they'd be fine, but that is not the case. They are sensitive to hot days over 90 F which we've had several here in Murrieta this week. I've gone out each day, looked at the grow tips and added extra water to ensure they could withstand the heat.

The other factor here is the vines vigor and age. If that vine is only in its second or third year and wasn't vigorous during the spring it's possible its carry too much fruit for it to ripen. Overcropping puts extra stress on the vine, which makes it even more susceptible to high temperatures. Typically the rule of thumb I've gathered is you should drop all clusters on the first and second season, then cluster thin to a single cluster per shoot on the 3rd season, then 2 clusters per shoot on the 4th season assuming the vine is vigorous.

Lack of phosphorus or potassium could also be a contributing factor.