cab franc flowering again in august
 

A puzzler. Two things have happened to my cab franc vines within the last
weeks. A week or so after topping shoots, I am suddenly noticing a potassium
deficiency in old leaves. I am assuming it may be because I topped too much
from new growth and the vine is translocating nutrients from older leaves.
Am I correct?

Secondly, I am noticing that new lateral growth on the upper canopy is
flowering again on a few vines. Nice tight baby clusters.

Are both phenomenon related in some way?

I've checked "General Viticulture", "Biology of the Grape Vine", and "The
Production of Grapes and Wine in Cool Climates". In all three publications I
haven't found any direct references to translocation of potassium as a
result of summer pruning. Nor have I seen reference to late (August)
flowering.

Baffled.
Jeff

Jeff Chorniak wrote:

> A puzzler. Two things have happened to my cab franc vines within the last
> weeks. A week or so after topping shoots, I am suddenly noticing a
> potassium deficiency in old leaves. I am assuming it may be because I
> topped too much from new growth and the vine is translocating nutrients
> from older leaves. Am I correct?
>
> Secondly, I am noticing that new lateral growth on the upper canopy is
> flowering again on a few vines. Nice tight baby clusters.
>
> Are both phenomenon related in some way?
>
> I've checked "General Viticulture", "Biology of the Grape Vine", and "The
> Production of Grapes and Wine in Cool Climates". In all three publications
> I haven't found any direct references to translocation of potassium as a
> result of summer pruning. Nor have I seen reference to late (August)
> flowering.
>
> Baffled.
> Jeff

Jeff, I do not know anything about possible potassium translocation but I
have found it common in my vineyard to have laterals that result from
hedging produce new clusters. I do not use them in my wine production and
in fact should probably drop them because I assume they are just using
energy that the vine and other clusters need.