# Roundup Ready alfalfa



## Winnie (Oct 13, 2015)

It is necessary to spray Roundup/glyphosate every year? I have a field of Roundup Ready alfalfa, now in its second year. I see absolutely no weeds. Should I apply Roundup/glyphosate anyway, or just go without spraying?


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## Teslan (Aug 20, 2011)

Your license agreement I believe has you agreeing that you are going to spray every year. However if no weeds then no need to spray.


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## endrow (Dec 15, 2011)

http://extension.psu.edu/pests/weeds/control/guidelines-for-weed-management-in-roundup-ready-alfalfa


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## vhaby (Dec 30, 2009)

I can't imagine a perfect alfalfa field with no weeds. You don't have to spray right now when you aren't seeing any weed growth. Wait a while and spray when you do see weeds growing later in the season.

What is your elevation? Have you seen any alfalfa weevils? Some of us combine spraying Glyphosate with an insecticide for weed and weevil control.


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## Winnie (Oct 13, 2015)

To vhaby: My elevation is 5300 feet. We had alfalfa weevils last year and sprayed for them. Thanks for the tip on combining glyphosate and insecticide. I hope the weevils stay away for a long time and don't have to spray for bugs.


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## endrow (Dec 15, 2011)

vhaby said:


> I can't imagine a perfect alfalfa field with no weeds. You don't have to spray right now when you aren't seeing any weed growth. Wait a while and spray when you do see weeds growing later in the season.
> 
> What is your elevation? Have you seen any alfalfa weevils? Some of us combine spraying Glyphosate with an insecticide for weed and weevil control.


 what height and growth stage are you at when you spray that tank t
Mix


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## endrow (Dec 15, 2011)

The reason I posted that question is I would think if you sprayed a Roundup Ready Alfalfa stand prior to First cutting the ideal time to do that would be long before you would spray an insecticide for weevil. But that's just here and that's me and I know many people have found a way to spray on both the same time and I wish I could too


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## vhaby (Dec 30, 2009)

Winnie, I don't wish weevils on anyone's alfalfa, but here they are like "death and taxes." Perhaps at your elevation, the temperature has not gotten sufficiently warm for them to emerge.

endrow, I sprayed Glyphosate and insecticide tank mixed for weed and weevil control when the alfalfa was at least 8 - 10 inches tall. I eradicated the weevil for now and got what weeds I could. I hoped that with 40 psi pressure, some of the spray got down to the low growing weeds. I'm monitoring the weed situation.


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## Vol (Jul 5, 2009)

Vincent, I also sprayed a few weeks ago for weeds/grass and weevils at about the same height. I was down into that particular field yesterday and noticed the grasses are pretty gold in color so they are about dead. I sprayed at 30 psi and it seemed to work fine.

But the bad news for me was that the freak cold we received last week with a low of 17° one morning really dinged my alfalfa. I am afraid the top1/3 was severely damaged. The early spring was a waste of time at this stage for me. The fruit crops were devastated.

Regards, Mike


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## pede58 (Oct 27, 2015)

Roundup is a contact killer, no weeds nothing to kill.


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## vhaby (Dec 30, 2009)

Mike, I'm sorry to hear about the frost problem on your alfalfa, and on the fruit crops. The California extension specialists likely are correct about the effect of a cold snap following Glyphosate spraying on alfalfa, but at 17 degrees, taller alfalfa shoots get zapped no matter what treatment, or no treatment, has been applied.

I'm happy to read in one of your posts, that the drought may be broken in your region.

Here, our blueberry bushes and peach trees bloomed way too early, and I'm still fearful that a frost is eminent. Our average last frost date is April 15th. So far so good.


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## hcriddle (Jul 5, 2014)

Mike sorry to hear about your alfalfa. Sounds like a lot of folks over that way are watching to see what the effects of that freeze are going to be on the crops.


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## FarmerCline (Oct 12, 2011)

Vol said:


> Vincent, I also sprayed a few weeks ago for weeds/grass and weevils at about the same height. I was down into that particular field yesterday and noticed the grasses are pretty gold in color so they are about dead. I sprayed at 30 psi and it seemed to work fine.
> 
> But the bad news for me was that the freak cold we received last week with a low of 17° one morning really dinged my alfalfa. I am afraid the top1/3 was severely damaged. The early spring was a waste of time at this stage for me. The fruit crops were devastated.
> 
> Regards, Mike


 Hate to hear last weeks freeze got your alfalfa. I was really worried about mine but it doesn't look like it hurt it too bad. About 10-20% of the plants in the field were wilted and it looks like it killed the top half of the stem but the rest of the plants ended up looking okay. The plants that got damaged by the freeze were a little different in appearance than the majority of the other plants in the field.


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## FarmerCline (Oct 12, 2011)

Those of you that spray roundup in the spring on RR alfalfa what weeds are you targeting to kill? I have both RR and conventional alfalfa fields and when I sprayed for weevils a few weeks ago there were no weeds to kill. During the summer months is when I get weeds coming into the alfalfa.....not before first cutting. Weevils here typically occur very early in the spring almost as soon as the alfalfa just starts growing.


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## Vol (Jul 5, 2009)

I am targeting grasses mostly at this time of year, but there can be a little hen bit and some of the early growing broadleaves like plantains, buttercups, mares tail....etc.

Some of these will only be about the size of soybean so they can be almost impossible to see if not down on your knees, but rest assured they are there.

Regards, Mike

Here is a good primer on the broadleaf early birds.

http://weeds.cropsci.illinois.edu/extension/Other/NCR614.pdf


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## FarmerCline (Oct 12, 2011)

Vol said:


> I am targeting grasses mostly at this time of year, but there can be a little hen bit and some of the early growing broadleaves like plantains, buttercups, mares tail....etc.
> 
> Some of these will only be about the size of soybean so they can be almost impossible to see if not down on your knees, but rest assured they are there.
> 
> ...


 What kind of grass weeds do you get this time of year? Grasses are also my main weed problem in alfalfa as well but the summer grasses like crabgrass, goose grass, and foxtail is what I have trouble with.


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## Vol (Jul 5, 2009)

Annual Bluegrass and some others that I have no idea what they are.....I just kill them. 

Regards, Mike


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