Weed Management in Vineyards Injured by the Polar Vortex – 2014

Cold injury experienced in our vineyards as a result of the ‘Polar Vortex’ this past winter will present great challenges in controlling weeds for many growers across the mid-west.

Most of us have come to the conclusion that there will be trunk and cordon injury in all but the hardiest of grape varieties. Because of this, we will need to bring up new trunks over the summer months to replace those damaged.

After our soil take-away operation is completed later this spring we will be watching for suckers to sprout from the base of the vine at just above the graft union.

We will want to maintain as many of these suckers as possible in order to manage vine vigor. There may be 10-15 or more suckers per vine (we hope).

Many of our damaged vineyards will act as if they are 2-year-old vines with many suckers originating from the vine’s base. These shoots will, most likely, have a high level of vigor.

Weed management in our vineyards will be a huge task.

 What management tools will you be considering for weed control in this year of rebuilding?

  • Should we go with maximum rates of stronger compounds in order to keep weed growth down as long as possible? Green suckers will be in the way pretty much the entire season.
  • Will a Polar Vortex weakened vine be more prone to injury from the stronger herbicides?
  • Are we better off using mechanical weed control?
  • With so many suckers in our spray zone, glyphosate will be a challenge to apply. We don’t want to burn our suckers off with Gramoxone either.
  • Should we hit the mounds with a strong dose of glyphosate before take-away  in an attempt to clean up any sprouted perennial weeds that could pose a problem later in the season?
  • Should we consider planting a competitive low-growing cover crop under the trellis in an attempt to reduce vine vigor and out-compete other, taller, weed growth?

Let’s discuss our options, opinions, and ideas via this Blog!

 

9 thoughts on “Weed Management in Vineyards Injured by the Polar Vortex – 2014

  1. Great question! This year, weed management will be the one thing growers won’t want to skimp on, so the vines are ready for next year. My students were just asking about this this week in class. I look forward to see input from growers in the know!

  2. Greg, great topic! I didn’t answer your inquiry because of all your appropriate questions. I love the idea of a cover crop after Tony Wolfe’s talk to control vigor-especially this year. But what cover crop? In a normal year I would use a pre-emerge and Rely (I have a little left) and spot spray throughout the season. Is a pre-emergent a bad idea with weak (if we’re lucky enough to have them) vines and suckers? This will be an interesting year with a lot to learn. ??? Thanks, look forward to reading great ideas–Lou

    • Lou- I’m going to make sure Doug Doohan is aware of this blog and I think he should be able to chime in to help us answer some questions. Tony Wolf was using creeping red fescue in Virginia. Although, he said they don’t hill-up and they keep the grass as a permanent cover. We have some people at OSU we could ask about cover crop ideas. It may not be a full solution but even if it helps some it might be worth a look-see. A tight low-growing cover crop might help control more aggressive (and taler) weeds. If it helps a little with vine vigor that is a bonus. Keep posting and share the blog!

  3. Interesting Stuff, Greg! Those are very difficult questions. I wouldn’t think cover crops would be enough to keep those young trunks happy. I like your idea of a nice strong dose before taking away the mounds.

    Greetings from NZ
    -Andy

    • Good to hear from you Andy. We are in a difficult spot this year. Repeated cold events, each alone would have caused damage. To compound matters, our vines weren’t at their hardiest. One reading in late December had Cab franc at LT50 of -6 f. and we would have expected them to be LT50 of -15 to -16 f. Even most tertiary buds are dead in most vinifera varieties. What do growers in NZ do to curtail excessive vine growth?

      • Greg,

        There’s a million dollar question. They don’t have the rainfall, nor quite the heat units that Northeast Ohio gets in the summer, so it’s not as severe a problem. Nevertheless it does come up.

        On a vigorous site, I think people would be looking to slow things down from the very start, i.e. rootstocks like riparia gloire. In a mature vineyard, inter row cover crops would probably be encouraged here, although some people question their effectiveness. I think Cover crops would be more likely to make a difference in Ohio conditions, where there is more potential for vigor. Another thing would be to look at the balance between reproductive and vegetative growth. That would probably entail leaving more fruit in this case to shift the ratio of the carbohydrate partitioning away from vegetative growth. Dr. Howell, retired from MSU, wrote pubished a great paper in 2001 on the Growth-Yield Relationship.

        If the problem is that canes aren’t having a chance to mature though, more fruit may not be a great solution! Maybe with early varieties, that would be a nice option. Otherwise, I’ve heard anecdotally that good sun exposure promotes maturation in the wood.

        Wow, plenty of variables here!

        Keep fighting the good fight,
        Andy

  4. For those who have a lot of emerged annuals or perennials and no above ground grape growth don’t hesitate to use burn downs of glyphosate, or paraquat, or Rely (if you have some). I don’t see an issue tank mixing either of these with a residual herbicide such as Karmex or Princep provided the vineyard has been established for more than three years. Karmex or Princep will keep additional annuals from establishing and this could be important if the time to take down the hill extends for more than a couple of weeks. When the hill is removed there will likely be a need for additional residual in the area where the soil is stirred. Considering the two-shot approach, the residual should likely be split into two equal portions, or a third early and two thirds after de-hilling. By this I mean halves or thirds of the total amount of herbicide that can be used in a year. The beauty of this approach is that Princep and Karmex have very little uptake through green tissue so a little overspray is not going to cause a problem; however, don’t mix other herbicides or adjuvants unless your are certain you can keep spray off the shoots and leaves.

    This brings us back to the basic question of what to do beyond the above. As Lou points out careful spot spraying is part of an integrated approach, but not for the faint-hearted. For all foliar active herbicides you can expect injury if the shoots are hit. When it comes to cultivation, one thing we know for sure is that ‘steel kills weeds’.

    Hope this helps.

  5. Root pruning might slow the vines down a bit, and the effects would be temporary. Green manures with a high C:N ratio could be used to starve the vines for N this season. Tilling them and/or weeds in will also open the soil to evaporation of water.

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