# Spraying Roundup Ready Alfalfa



## adcraig02 (Jan 30, 2017)

Hello,

I am new to roundup ready alfalfa this year. I have a 16 acre field in northern NV that is irrigated via flood irrigation. It has a new stand of RR alfalfa that was planted last spring. 2 cuttings were taken off of it last year. I just bought this field this past winter.

This year the alfalfa looks very good. However there is quite a bit of mustard weed (aka...flixweed) growing. I would like to spray it out. The alfalfa is just beginning to grow and I see everyone else spraying so I think the time is right.

My question is what mix / ration do most people use on the RR alfalfa? I have read anywhere from 28 to 44 oz of roundup per acre. I am trying to figure out how many gallons of water to add to that. I have a 26 gallon boom sprayer that pull behind my JD gator.

My going in gameplan is going to be to use 35 oz of big n tuff, 13 gallons of water, 6 ounces of surfactant and 16 ounces of ammonium sulfate per acre (double all that to mix a tank of spray). If anyone has experience spraying RR alfalfa I would really like to hear if you think I am on the right track or if my mix sounds off.

I just assume Big N' Tuff is ok to spray since it's label says it can be utilized on RR alfalfa. If that is incorrect please let me know.

Thank you in advance for all the advice.

Thank you,

Andrew


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## Vol (Jul 5, 2009)

Hire it done. You will need to put down at least 10 gallons of water per acre and 22 oz. of 41% glyphosate(roundup) per acre. I know nothing of Big n Tuff. There is more to spraying than just "spraying".

Regards, Mike


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## adcraig02 (Jan 30, 2017)

Mike - thank you for the input. Your numbers are pretty close to mine regarding gallons of water and oz of glyphosate. I will not be hiring it done. I like to do things myself. I have successfully sprayed Pursuit, Raptor and many other chemicals on traditional alfalfa myself. While there is more to spraying than “spraying” it isn’t rocket surgery to spray a field - I have done it many times in the past. I have just never used roundup ready alfalfa.


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## vhaby (Dec 30, 2009)

Vol is correct about weed control in Roundup Ready alfalfa using 22 oz. of Glyphosate/acre. You can mix 44 oz of Glyphosate in your 26 gallon spray tank and use a surfactant if you desire, but it is not necessary. What you definitely want to check the alfalfa for is weevil activity. If they are at a threshold level, you may want to tank mix an insecticide with the Glyphosate to kill the weevil and have two or three weeks residual control. I have used Tombstone and Dimilin with the Glyphosate on my RR alfalfa and get good control. My RR alfalfa is ready for first harvest- waiting for a 5-day rain free window that may start this coming Saturday.


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## endrow (Dec 15, 2011)

The form of glyphosate herbicide you use must have a page in the label specifically for Roundup Ready alfalfa. Many of these generics have a label section for Roundup Ready corn and beans and cotton but not alfalfa. The latest generation of Roundup Ready alfalfa can only be sprayed with Power Max or weather Max is what I was just told at the last Growers meeting. But again if I was going to spray it I would look at the product label on the jug that I was using and I would follow those instructions..


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## Vol (Jul 5, 2009)

adcraig02 said:


> Mike - thank you for the input. Your numbers are pretty close to mine regarding gallons of water and oz of glyphosate. I will not be hiring it done. I like to do things myself. I have successfully sprayed Pursuit, Raptor and many other chemicals on traditional alfalfa myself. While there is more to spraying than "spraying" it isn't rocket surgery to spray a field - I have done it many times in the past. I have just never used roundup ready alfalfa.


How wide is the boom on your sprayer Andrew? Is your sprayer calibrated? Vhaby is correct in adding your insecticide to the mixture....especially for the weevils this first go around.

Regards, Mike


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## endrow (Dec 15, 2011)

Vol said:


> Hire it done. You will need to put down at least 10 gallons of water per acre and 22 oz. of 41% glyphosate(roundup) per acre. I know nothing of Big n Tuff. There is more to spraying than just "spraying".
> 
> Regards, Mike


 from reading labels over the years I am thinking the minimum 22-ounce rate is for PowerMax or weather Max.. the minimum rate for 41% gly it's just a smidgen higher. But I didn't specifically check the labels today for this application just going by what I've seen over the years you'd want to check the label.. I know just like everything else the darn rules on this GMO stuff for tightening up all the time.. you can go down to Tractor Supply and buy a gallon of Roundup and do whatever you please but when you buy the Roundup Ready seed the first thing it tells you in the technology agreement you're responsible for proper Roundup stewardship. And it is getting to be more and more pain in the butt and I guess that is why more and more people look for alternatives


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## endrow (Dec 15, 2011)

adcraig02 said:


> Hello,
> 
> I am new to roundup ready alfalfa this year. I have a 16 acre field in northern NV that is irrigated via flood irrigation. It has a new stand of RR alfalfa that was planted last spring. 2 cuttings were taken off of it last year. I just bought this field this past winter.
> 
> ...


 Not to be a smart alec , but I'm going to bet this form of Roundup you're talking about here, in regards to Roundup Ready crops, can only be used, on the first generation of Roundup Ready corn and soybeans. Be sure to check the label on The Jug you buy


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## mlappin (Jun 25, 2009)

Been told to figure using 10% more of a generic compared to name brand roundup.


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## adcraig02 (Jan 30, 2017)

I wanted to follow up on this in case anyone else wanted to do this themselves. I got my field spayed and it went just fine. The weeds are all dying and there is no damage to any of the alfalfa. I utilized Cornerstone 5 Plus which is 53.8% glyphosate (normal Roundup is 41%). It doesn't really matter whether it is "name brand" or not. The % of glyphosate is all that really matters. Big N' Tuff is 41% - exact same as normal name brand roundup.

To spray the field I mixed 16oz of Cornerstone 5 Plus in 13 gallons of water to spray 1 acre. If I were to use 41% then I would have put in 22oz of normal round up in. However, the Cornerstone 5 Plus is stronger so not as much was required.

Thanks for all the help getting me pointed in the right direction. The only thing I would have changed if I had to do it all over was spray earlier. The mustard weed was 8 - 10" tall by the time I sprayed. The better farmers in my area sprayed about a week earlier than me and got it when it was 4 to 6" tall.


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## somedevildawg (Jun 20, 2011)

Did ya check them weevils?


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## endrow (Dec 15, 2011)

somedevildawg said:


> Did ya check them weevils?


 I sprayed my Roundup Ready Alfalfa 3 days ago I put bug spray with


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## endrow (Dec 15, 2011)

adcraig02 said:


> I wanted to follow up on this in case anyone else wanted to do this themselves. I got my field spayed and it went just fine. The weeds are all dying and there is no damage to any of the alfalfa. I utilized Cornerstone 5 Plus which is 53.8% glyphosate (normal Roundup is 41%). It doesn't really matter whether it is "name brand" or not. The % of glyphosate is all that really matters. Big N' Tuff is 41% - exact same as normal name brand roundup.
> 
> To spray the field I mixed 16oz of Cornerstone 5 Plus in 13 gallons of water to spray 1 acre. If I were to use 41% then I would have put in 22oz of normal round up in. However, the Cornerstone 5 Plus is stronger so not as much was required.
> 
> Thanks for all the help getting me pointed in the right direction. The only thing I would have changed if I had to do it all over was spray earlier. The mustard weed was 8 - 10" tall by the time I sprayed. The better farmers in my area sprayed about a week earlier than me and got it when it was 4 to 6" tall.


 I agree the important thing is the active ingredient and the height of the weeds. The tag on the seed bag for Roundup Ready alfalfa allows for an individual application of .75 to 1.5 pounds active ingredient. At 10" in Weeds I would want to be at the bare minimum of one pound at active ingredient per acre.


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## endrow (Dec 15, 2011)

We found weeds and I are Roundup Ready alfalfa. The picture is deceiving 5-inch weeds 5-inch alfalfa. A lot of henbit chickweed down below yet and some others. We used one quart to the acre of PowerMax


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## Gearclash (Nov 25, 2010)

I would talk with an agronomist about spraying your alfalfa before you do anything. And make sure your sprayer is totally, completely clean before you spray. I’ve seen damage on alfalfa from herbicide residue in the sprayer. Glyphosate first came into being as an industrial solvent and it still works like that today.


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## pvcman (Jul 18, 2014)

I use a 2% mixture of a generic Glyphosate at a rate of about 25g per acre. I sprayed three times last season (1st season) and once to begin this year. The stand is really looking strong now. First cut went in the barn on 4/12. 2nd cut should happen within the next week if I get a dry window.


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## Mellow (Jun 22, 2015)

I would leave out the ammonium sulfate, no need for this in RR alfalfa.


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## kurt1981 (Apr 18, 2017)

read the bottle of what your spraying and read the package that your nozzles came in to figure out speed to drive and pressure to set the sprayer at to figure out rate and flush the sprayer out before you fill it. If your sprayer is at a fixed pressure the you will just drive faster of slower according to your calc. Dont think you need to consult an agronimist.


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## endrow (Dec 15, 2011)

Everyone needs to do their part to be a good Steward of glyphosate not creating additional resistances. Agronomists in my area recommend for any application the bare minimum of .75 pound active ingredient glyphosate. https://extension.psu.edu/guidelines-for-weed-management-in-roundup-ready-alfalfa


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