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September 28, 2004

Row Widths

Thought I'd share some of the variables and challenges that go into determining row width when planning a vineyard.

I've been discussing the layout of the vineyard with Doug (Fabbioli - Vineyard Consultant) over the past few days. Last year we had Virginia Cooperative Extension Agent Jason Murray out to the land to share his ideas for setting up the vineyard. Read about that visit here. During that conversation we had established a row width of 8' and vine spacing of 6' on VSP trellis. Then in March 2004 we attended a vineyard seminar during which we confirmed that our row and vine spacing were fine, although we did reconsider the trellising and began leaning towards a Smart-Dyson divided canopy configuration. But after visiting Jewell Towne Vineyards in New Hampshire for Shannon's birthday in May 2004 we again thought VSP may be the way to go since Dr. Oldak advised that the lower half of the canopy is more susceptible to fungus since much of it ends up lying on the ground.

You can already see how many different inputs and differences of opinion go into this decision, not to mention the hundred-or-so magazine articles and online research papers that we've read!

So in talking with Doug, he suggested that we actually widen the rows to 9' and tighten the vines to 5' and reconsider the Smart-Dyson trellis. Doug's rationale for the wider row spacing was for ease-of-maintenance in maneuvering a tractor through the rows. This is not a minor point! Our tractor is currently just under 6' wide, so in an 8' row you have basically 1' on either side. If you blink you could mow down a vine - not good.

In addition Doug has identified the least-fun aspect of managing a vineyard as spraying fungicide. Fungus prevention is a fact of life in Virginia vineyards due mainly to the high humidity in our region. You're not going to see any 'organic' vineyards in Virginia. It's all about chemicals and technology for us to be successful. So a typical growing season requires about 12-15 sprayings after a rainy period. Each acre requires about 45 gallons of spray for proper coverage.

So why not just get a smaller tractor to fit through the rows? Horsepower. hp is critical in any kind of farming. Our tractor (John Deere 850 with a front-end-loader, no cab) is about 25hp, which can operate a three-point sprayer with a 50-gallon capacity. That means for four acres:

spray an acre - go reload - spray an acre - go reload - spray an acre - go reload - spray an acre

Probably be about 6+ hours per spraying, and that is moving quickly.

So now along with the row widths we are reconsidering our tractor - do we upgrade? The decision is tough because you basically are trading an acre of grapes ($15,000) for the tractor upgrade. The higher hp and cab on the tractor would be awesome, and allow for a higher output sprayer (which translates to fewer 'go reload' steps) which helps make the least-fun part of vineyard management much more enjoyable.

Not to say that tractor hp and size are the only considerations in determining row width. Row width also has implications for vine vigor, which ultimately affects fruit quality thus wine quality. In addition, having rows too close together may impact the ability of the sun to reach the grape clusters. This is caused by the height of the adjoining row shading the clusters (if your strategy includes cluster exposure.) This is further complicated by the aspect of your vineyard slope in situations where you want to train your canopy on the west side of the row to shade the clusters from the hot afternoon sun while still exposing them in the mornings to quickly heat the dew off the bunches to help prevent mildew.

And to state the obvious, once the trellis and vines are in the ground they do not move. Can't "scoot them over" a foot a year later...

Much more to follow on this challenging topic! We love it!!!

Posted by Stephen at September 28, 2004 9:15 AM