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Glyphosate damage to fruit trees

ltilton
9 years ago

I think it was here that we were discussing the use of RoundUp to kill grass around fruit trees. This recent publication from the Illinois extension has made me have second thoughts about the practice.

Here is a link that might be useful: glyphosate damage

Comments (19)

  • alan haigh
    9 years ago

    Gives me second thoughts about going to them for advice- not a single detail of why the damage occurred. Most commercial growers of fruit use glyphosphate liberally- if such damage was anything but extremely rare, when used properly, my guess is they wouldn't.

    But I don't use it.

  • jean001a
    9 years ago

    I didn't read the article.

    But the reasons for damage is that glyphosate can, and does, travel on the air, either via wind or via spray turbulence.

    Also, can go through thin bark of young trees as well as into the cracks in the bark on older trees.

    And another route is via exposed roots.

  • alan haigh
    9 years ago

    As I understand it, It's not so much it goes into the bark as it is transported to the roots via chlorophyll where in does it's damage- therefore young, green bark can transport it. This is well known.

    Issues with roots on non targeted trees that are "grafted" or merged with sprayed plants are not relevant in most orchard situations as you are not spraying well established plants.

    Other herbicides are much more volatile and inclined to injure plants by way of vapor on warm days.

    All instructions about herbicide application tend to address the problem of drift.

    The article didn't go over any of this or say what went wrong. How is that useful?

  • marc5
    9 years ago

    In the past two years I have used glyphosate around more than 200 of my fruit trees to control grass and weeds. Most of the trees are pawpaws, but many are apple, pear, and stone fruit. I spray very close to the trunk--some trees are large and old, some are 1/4" diameter. I have never seen any damage to the trees. However, I am VERY careful: no wind, low pump pressure, large droplets. No spray on trunk or foliage. It does a marvelous job, and I can then spread mulch. Weed and grass control is critical, especially for young trees.

  • fireduck
    9 years ago

    I thought the article was pretty clear that the "drift" of glyphosate was the cause of the problem. Also, I found it interesting that the herbicide is "stored" within the tree to the following season. Wow! I use quite a bit of this stuff. My concern has always been the transfer through the tree to the edible fruit.

  • alan haigh
    9 years ago

    That is a newsletter for commercial producers. I believe the remark about glyphosphate damage should have included a lot more information than just to say it was a problem of drift- that is always a concern with any herbicide you spray. A little context could go a long ways- method of ap, weather conditions and so forth. A little information may cause more anxiety than do any good.

  • alan haigh
    9 years ago

    Here's an example of a more thorough explanation of a similar problem.

    Here is a link that might be useful: glyphosphate damage in almonds

  • fireduck
    9 years ago

    h...that is a much better article...isn't it?

  • spartan-apple
    9 years ago

    I sprayed Roundup two weeks ago around my young and old fruit trees. I always spray herbicides at sun up and
    only when dead calm. I got out my cardboard too to make a temporary shield that I use around the trunks of young fruit trees to avoid contact with the bark.

    The weeds are dead, the trees are good. I just want to point out SAFE if used appropriately.

  • ltilton
    Original Author
    9 years ago

    I have this notion of applying it with a paint roller.

  • alan haigh
    9 years ago

    The reason I reacted with strong negativity to that alarming but relatively uninformative article is that we fruit growers have enough anxiety issues to begin with- so much can go wrong.

    You read an article like that and if you sprayed roundup a few days prior you might start to feel a little sick even if you did everything right.

  • fireduck
    9 years ago

    I get it...it is not easy being a farmer...haha.

  • bonnan
    9 years ago

    HM...If you don't use Round-up how do you treat the area under the tree? Thx

  • lazy_gardens
    9 years ago

    From a comment follow-up on the article about almonds ...

    "The injury observed in this orchard was traced back to a completely unexpected (by me anyway) exposure to glyphosate. Before planting, the planting crew sorted and prepared the dormant, bare-root trees on a cement floor on which glyphosate had been spilled (sprayer storage area). Some of the trees apparently picked up enough glyphosate up from the wet floor to cause the injury we observed in the field a few months later. An interesting twist for sure. "

    Uhhhh ... sloppy handling technique!

  • ltilton
    Original Author
    9 years ago

    Well, it worked for me! I was instantly filled with anxiety!

  • bob7557
    9 years ago

    Is there a herbicide combination that anyone has had good success with and willing to share, that keeps ground under fruit trees relatively free of grass & weeds for most of the season? Despite these concerns about Glyphosate damaging the tree itself, even in a perfect world it only lasts about a month and then has to be re-sprayed. Commercial growers all seem to have a different "cocktail" that gives them more/less clean areas below the canopy. Just curious if anyone on here has something they've used with success?

  • olpea
    9 years ago

    Bob,

    Most commercial growers use a pre-emergent to control weeds. I've been reluctant to do this at the farm because the trees are young and more susc. to pre-emergent herbicide uptake.

    Last year I bought some simazine but never did use it. I've got a huge problem with field bindweed, so I plan to use a pre-emergent next year. I'm looking into Prowl H2O. I've also heard a lot of good things about Sinbar. Chateau and Matrix are a couple other options. Some of these pre-emergent herbicides can be very expensive, so that is a consideration. Glyphosate is pretty cheap at roughly $35-$40 for 2.5 gal. Compare that to hundreds of dollars for some of the pre-emergents.

    This year we pretty much mowed, or sprayed gramoxone. Gramoxone is good for young, non-bearing trees because it has no systemic activity (so it won't kill young trees, unless the applicator is very sloppy and sprays the green bark of young trees). The downside is that there is no residual effect. It's only a burndown, so weeds pop right back up (although weaker). It's basically chemical mowing. Gramoxone is also very hazardous to humans, so all the PPE should be worn.

    I don't know if this post helps you, but the real lesson, if you have lots of trees, is a good pre-emergent.

  • bob7557
    9 years ago

    Thanks. I agree on the gramoxone and have used that on young trees. Have also used in combo with pre-emergents Prowl & Simazine, and have gotten nice weed-free beds in some areas but lots of growth in others. I need to take time to determine which weeds and/or grasses are breaking through. Just one more thing to do that I have not made the time for. Was hoping for some super cocktail recipes that would be a 1x application, not hurt the trees or their growth, and keep everything free from ground competition.....i.e. a super spray!! I will stay tuned for other replies. Thanks again.

  • Toronado3800 Zone 6 St Louis
    9 years ago

    Be careful with roundup around trees which may sucker is my advice.

    Now I spray the stuff ON the honeysuckle bushes and sometimes it doesn't kill them. But still I am careful around trees I like.