Thursday, May 1, 2014
After a quick shufty through all of my viticulture books with no satisfactory findings, I turned to the internet - not much joy there either I'm afraid. The conventional wisdom online is that the main reason for a secondary shoot pushing is the death or removal of the primary shoot. Call me old fashioned, but I think the primary shoot in the photograph looks very much alive. The second reason is perhaps that the vine has suffered a severe pruning. Nope, I prune the same every year - 2 eight-bud canes and 2 two-bud spurs (5' by 7' spacing) which, in my opinion, is not that severe. The third reason given is boron deficiency. Ha! Coombsville is known for boron toxicity: a neighbour of mine even trucks in water for their vineyard because their boron-rich well water would kill their vines.
Not being happy with any of my findings, my last resort was to email Dr. Stephen Krebs, my VWT professor at NVC (who, I just found, out is retiring this summer and I am just devastated by the news). If there is one, ultimate viticultural-brain to pick then Dr. Krebs is in possession of it. And he said;
"As for the multiple-bud push, the only explanation that makes sense, of the ones you listed, is severe pruning (which translates to “over exuberance”). If you combine that with a lot of soil moisture and warm, sunny conditions at bud break, I think you get many doubles and even triples."
And there you have it, at least I am satisfied with that explanation. The climatic conditions at budbreak were such that all of Vinoland's vines were invested with a natural exuberance - which translates as a lot of suckering and thinning in Vinogirl's near future. I love vines.