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