Spraying Round Up

Fergienewbee · Nov 2, 2009

I sprayed RU on some mowed grass/weeds for next year's food plot. I did the math wrong and mixed two quarts in 40 gallons rather than two quarts in 20 gallons. I went over it twice, so in affect put on 80 gallons of 2.5% solution. Would that be close to the same as one pass with a 5% solution? Also,how much does temperature--it was about 55 degrees when I sprayed--affect potency?

Larry in Michigan

JBMac · Nov 2, 2009

Glyphosate works best when plants are actively growing. Cool temperatures and drought can reduce efficacy. In my experience, 4-5 qts per acre will control most weeds. If you broadcasted somewhere near that amount, I think you"ll be ok.

JBM

rrlund · Nov 2, 2009

Those 23 degree mornings that we had just about put an end to Roundup having much effect I'm afraid. The other thing is,after you went over it the first time,it likely wouldn't have done anything the second time over even if it was growing. When that stuff hits the growing plants,it kind of has the effect of "stinging" the cells and shutting them down so that just a few minutes after application,they have shut down and won't absorb anymore. As far as the 2.5% solution vs 5%,really doesn't matter. It's the amount of actual product per acre that counts. The water is just the carrier that gets the product on the plants.

Mike (WA) · Nov 2, 2009

Probably too late for Roundup this year- it isn't the temp at the time of spraying that counts so much, its the dormancy of the plants- and I would imagine they're pretty much dormant by now, except in the deep south.

5% solution? I've always sprayed 1 1/2% in the spring and get complete kill- but I'm using a hand sprayer, so may be getting more product on.

JMS/.MN · Nov 2, 2009

I think you should park the sprayer until you learn how to use it and herbicides. It"s a shame that anyone can buy roundup. Nothing but mistakes here.

Anonymous-0 · Nov 2, 2009

Doesn't matter much how many gallons of water per acre, just the amount of herbicide. So you can spray 2 qts of RU an acre using either 20 or 40 gallons acre providing 2 qts of RU still get applied. However, if you put so much water on that the stuff begins to run off the plants, you are losing benefit. This late probably should have used 4 qts/acre and still might not have the desired kill. Agree with the others, better to wait until next spring.

Anonymous-0 · Nov 2, 2009

That was impolite!

thurlow · Nov 2, 2009

Ain't seen you around for awhile; doesn't hurt to have some opinions from the distaff side. Sometimes the truth 'hurts'........as in JMS's post. I'm always amused (for lack of a better word) when someone asks for advice about what chemical to use for a specific application and almost everyone answers, "Round-up." Glysophate is a great chemical, but.....depending on the plants in question, there are often much better chemicals available. It's just that Round-up is the only agricultural chemical many folks have ever heard of.........

JMS/.MN · Nov 2, 2009

I"m not surprised at the criticism....it was expected, yet I made my post with no trepidation. I"m a semi-retired full-time farmer...one who cares about the image we project. The public has legitimate concerns about herbicide and fertilizer use. Real farmers calibrate their equipment and know how many gallons per acre of water are applied, along with the rate per acre of herbicide, oftentimes down to a fraction of an OUNCE!. We don"t mix a percentage of water and herbicide. We don"t double up applications. When herbicides show up in ground water, who gets blamed? The farmer- not the part-timer who doesn"t have a clue what he put on. I don"t know about herbicides, but the total pounds of fertilizer applied for urban uses is MORE than what is used for agricultural use. (Source? American Fertilizer Institute) Yet, who gets blamed for run-off? Inexperienced people need to learn, and it takes more than any one minute message that can be gotten here. Until then, park the equipment.

Anonymous-0 · Nov 2, 2009

First, don't mow prior to spraying RU, more leaf area means better plant absorption. Second, If you are trying to kill warm season stuff that has already been frost killed, you are wasting time, and RU. 2.5% RU should kill almost everything that is actively growing, give it a week or 10 days, to see results.

JBMac · Nov 3, 2009

I agree with below- I'm the general manager of an herbicide sales and application company. I cant tell you how many people come in and ask "How much do I put in my 40 gal sprayer?" My reply is "How many gallons of herbicide and carrier does your sprayer apply per acre?" I'm usually met with a blank stare, then begin teaching a calibration class.

Spraying Round Up

Fergienewbee

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JBMac

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rrlund

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Mike (WA)

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JMS/.MN

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Anonymous-0

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Anonymous-0

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thurlow

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JMS/.MN

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Anonymous-0

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JBMac

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