Some cordon areas lacking buds - 4th year vines

[we5inelgr]

Hi All,

I've got some Cab Sauv and Petite Sirah vines in our backyard. This is their 4th year and already well into bud break.

I noticed last year, and again this year, that there are buds missing from a few of the cordon area's, particularly on the Petite Sirah. It looks like all renewal spurs have buds on them so this appears limited to some parts of the cordon that are having issues with buds growing.

After harvest last year (3rd year leaf), I fertilized with this: Blue Planet Nutrients Liquid Blue Bloom Booster 2-4-10.

What might cause this and can it be corrected so that buds sprout from these areas?



Thanks!

 

[GreginND]

It doesn't look like you have any particular problems with diseases or anything so it could be just some cold damage at some point. Sometimes they just don't bud out. I would grow a cordon renewal cane this year from the center near the trunk and then lay that down next year as a new cordon. If you are worried about losing some yield, you can even leave the damaged cordon next year and grow shoots from both the new and old cordon. If you leave both, I would prune spurs on the old cordon to one shoot though to make sure your shoot density is not too high.

 

[wxtrendsguy]

Not at all unusual for these and several other varieties. The cause is apical dominance.

Depending on the vigor of your site you can do 2 things to fix this. Both require new cordons.

Very vigorous site: Encourage and retain a number of canes near the head of the vine that will make good cordon replacement candidates next year...you will likely get a bull cane in there too and if you do let it grow just don't use it next year, however if that bull cane is sucking up all the vigor of the plant and retarding other canes from growing then at least hedge it sometime in July. Now next year select a nice cane about 3/8" thick with buds about every 3" apart. Tie that cane down to your fruiting wire and let it run a few buds longer than you want your final cordon length to be. Wait till bud break, its very likely those buds at the end of the cane are going to push first, once they are say 1" long make a pass through the vineyard and cut your cordon back to the final length you desire. (yes you will cut off those newly opened buds) This will force the mid cordon buds to begin to push. Once you see a leaf or two from most of the buds on the cordon and make another pass through the vineyard and break off every other bud so that you have a shoot every 6" or so, also break off any extra shoots coming from positions you retained...no rabbit ear shoots.

Less vigorous site: Again encourage canes to grow near the head of the vine. Next year choose a nice 3/8" thick cane to replace the cordon. Tie the cane to the wire and cut it off at about 18" in length. Assuming your plants are spaced 6ft apart this will leave you with a 3 ft gap between each plant this year. Once bud break happens make a pass through the vineyard and again break off every other shoot so that you begin to establish positions approximately 5-6" apart and make sure there is only one shoot growing from that position. In the following year one of those shoots near the end of your short cordon is likely to have grown significantly, choose the one that looks least bullish and tie it to the wire to extend your cordon to the full length, again thin your positions on the new cordon to every other and prune the shoots on your 1 year old portion of the cordon to 1 bud plus 1 basel bud.

 

[BigH]

Hi All,

I noticed last year, and again this year, that there are buds missing from a few of the cordon area's, particularly on the Petite Sirah. It looks like all renewal spurs have buds on them so this appears limited to some parts of the cordon that are having issues with buds growing.

It looks like you are trying to spur prune since your cordon is 2 or 3 years old (based on the appearance of the wood). If that is the case, I am curious why you didn't retain spurs in those bare stretches. Did shoots grow from those nodes last summer? It looks like some of them had shoots last summer, but that you pruned them off right next to the cordon before this growing season. You should have retained 1 or 2 buds from smooth 1 year old wood.

You might get some basal buds to pop from those nodes. It looks like some might be pushing through now. They won't be fruitful this year though, and you might not get enough nodes to pop to make the cordon worth keeping. I agree with the others. Look for some nice shoots to train out from the head into a new cordon.

If no shoots have grown from those bare nodes dating back to when your cordon was a 1 year old cane, then yeah, you just got unlucky. When you prune your cane/cordon next year, retain the first bud on any pencil thick laterals that grow (if any). They might be more winter hardy than the bud in the nook at the base.

H

 

[we5inelgr]

Thank you all for your replies and suggestions, I appreciate it!

New cordon's it is.

And yeah, those areas without a bud, never had a bud/cane from year 1.