The clock is ticking! Here's my situation- I frost seeded about 18 acres of switchgrass from late January into late February. In mid April I contracted with the local ag supply to spray Atrazine and glyphosate on the plot. Well, rain and mud have kept them from doing the job, and now I'm starting to think it may not dry out for a couple of more weeks. I know LC said May 10th at the latest for glyph on newly seeded switch, but should I rely on soil temp readings more than calendar dates this year? We've had a lot of cool weather, and I'd really like to get a good gly burn on the chickweed and purple dead nettle. Is there a criteria I should use to tell me to cancel the gly in the mix?
Timing for switchgrass and herbicide
- Thread starter KDdid
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- switch grass weed control
Bill
Administrator
Swiffy asked a similar ? few days ago. He still has snow so it's a different circumstance. If it drys out enough to spray before the 10th I'd try it. Scout the field for small grass beginning to sprout. If you see a lot dig some up from different areas and leave the dirt intact. Baby switch is hard to identify from any other grass but if you gently wash the dirt away from the grass the seed will still be attached. Switch send a tap root down and blades up. I've used this method to ID germinated switch in the past. South slopes and tops are where it's likely to germinate first.
If you determine there has been a high germination rate maybe forego the gly and only spray the Atrazine. Just don't give up on it. I had what I was sure was a failed planting. Spring of year 3 we hit it with gly and atrazine and it came out of the wood work.
If you determine there has been a high germination rate maybe forego the gly and only spray the Atrazine. Just don't give up on it. I had what I was sure was a failed planting. Spring of year 3 we hit it with gly and atrazine and it came out of the wood work.
Bill does Atrazine have any effect on young seedlings? We are forecast for 5 dry days next week (I'll believe that when I see it), and about the only thing I see in the field right now is broadleaves. My biggest problem is that I'm down the priority list being only 20 acres or so. How late would you think that atrazine would be helpful?
Bill
Administrator
If you're not seeing much grass (look close)
I'd spray. Atrazine alone won't kill emerged weeds that's what the gly is for. The atrazine is to keep more from germinating.
Existing stands will grow earlier than a new seeding. So if the neighbors old stand is growing it doesn't mean much for your hard seed waiting to germinate.
Yes Atrazine can hurt new sprouts because they use crop oil with it. It's a balancing act. You may kill some switch that has germinated but save the majority that hasn't. If you're only seeing broad leaf as the majority of growth in the field stick to the gly and atrazine.
I know about being the small guy on the list. 18 acres of switch isn't cheap but the sprayer guy has 100's of acres of corn that ain't cheap.
If you get to the point of no go with the gly and atrazine because you have switch coming on strong don't sweat the broadleaf. You can keep it mowed at about 12 inches or wait until the switch is past the 4 leaf stage and hit it with 2,4-D.
I'm assuming the field was burned down last fall or in beans last summer. If so grass shouldn't be a major problem and you should be OK no matter what the field looks like this summer. Broadleaf is easy. Even gly resistant pigweed won't be able to shade out your switch. Chickweed will run its course early and not hurt you.
The hardest part of growing switchgrass is relaxing. If it looks like a failure this year give it another year or spray atrazine next fall/winter or gly and atrazine next spring early.
I have eaten many finger nails over switch. If you started right in the fall its probably going to be good.
I'd spray. Atrazine alone won't kill emerged weeds that's what the gly is for. The atrazine is to keep more from germinating.
Existing stands will grow earlier than a new seeding. So if the neighbors old stand is growing it doesn't mean much for your hard seed waiting to germinate.
Yes Atrazine can hurt new sprouts because they use crop oil with it. It's a balancing act. You may kill some switch that has germinated but save the majority that hasn't. If you're only seeing broad leaf as the majority of growth in the field stick to the gly and atrazine.
I know about being the small guy on the list. 18 acres of switch isn't cheap but the sprayer guy has 100's of acres of corn that ain't cheap.
If you get to the point of no go with the gly and atrazine because you have switch coming on strong don't sweat the broadleaf. You can keep it mowed at about 12 inches or wait until the switch is past the 4 leaf stage and hit it with 2,4-D.
I'm assuming the field was burned down last fall or in beans last summer. If so grass shouldn't be a major problem and you should be OK no matter what the field looks like this summer. Broadleaf is easy. Even gly resistant pigweed won't be able to shade out your switch. Chickweed will run its course early and not hurt you.
The hardest part of growing switchgrass is relaxing. If it looks like a failure this year give it another year or spray atrazine next fall/winter or gly and atrazine next spring early.
I have eaten many finger nails over switch. If you started right in the fall its probably going to be good.
Thanks for such a thoughtful response. The field has been in corn-soybean rotation for about 30 years, so grass shouldn't be a problem. I'll keep checking for sprouts, and make the call on spraying in the next week or so. At any rate, temperatures flirting with the 30's next week should help slow things down.
SWIFFY
5 year old buck +
Thanks from me as well!
We had snow on Monday and its 77 today! I saw the MDA Soil temps for my area currently are right at 50 degrees... thats 6" down. I may just hold off on the gly for now and do the 2,4-D later. It was all brome but I did get a pretty good burn during my August application.
Sound smart? I DO NOT want to figure out I cooked a bunch of my new little switch coming up because I applied my gly too late....
We had snow on Monday and its 77 today! I saw the MDA Soil temps for my area currently are right at 50 degrees... thats 6" down. I may just hold off on the gly for now and do the 2,4-D later. It was all brome but I did get a pretty good burn during my August application.
Sound smart? I DO NOT want to figure out I cooked a bunch of my new little switch coming up because I applied my gly too late....
Bill
Administrator
Scout the field good, dig up some grass and do the gentle wash looking for seed. If you're seeing mostly broadleaf I don't see anything wrong with waiting and using 2,4-D. But if there isn't much grass why not use the gly.
Lots of guys get good stands in year one. Mine have looked terrible year one but I never mowed or sprayed for broadleaf.
Even if it looks like a loss this summer spray again next year weather permitting.
So over the weekend I walked the field, and looked till my eyes were crossed, and I see no evidence of any new grass seedlings. There are only a smattering of grass clumps throughout the plot, but they all have established root systems, and are certainly CSG remnants from last year. With the lows the last two nights in the low 30's, I might have enough time to still stay with the original plan. Praying for the rain to miss tonight, might be able to string together 4 dry days in a row!
Bill
Administrator
Worry in June when the over night temps are over 70 for week.
Put tape on your fingernails. :)
Well, 10 days following my first post on this thread, I pulled the plug on spraying guy and atrazine. When I walked into the field today, I started seeing grass sprouts scattered about. I dug some up, and positively identified that they were emerging from seed. So, on to plan B. Any idea how long it will be to reach the 4 leaf stage?
On a side note, I was impressed with how far the seed had worked into the soil via frost seeding. Most of the sprouts that I dug up and washed had the seed around 1/4 to 3/16 of an inch below the surface.
On a side note, I was impressed with how far the seed had worked into the soil via frost seeding. Most of the sprouts that I dug up and washed had the seed around 1/4 to 3/16 of an inch below the surface.
Bill
Administrator
The grass that's up now should be there in a couple weeks depending on overnight temps. Personally, I would wait about a month to give the rest of the seed a chance to catch up. I'd rather get a so so kill on the broadleaf then defeat the purpose by stunting or killing the switch seedlings. Purple nettle and chick weed won't grow to tall anyway. If you had a field full of ragweed I might get on it sooner.
SWIFFY
5 year old buck +
Bill, so you are saying wait before spraying the 2-4D? I have some low broadleafs in mine but nothing too terribly bad... im thinking of letting it get a little higher before applying the 2-4D. I see very little grass anywhere right now. Yesterday was our first day in the 80"s. Thanks
Bill
Administrator
I've only ever sprayed it later in June. It might be fine to to spray on new seedlings but I read in some of my literature wait til the 4th leaf stage. Never having done it earlier, I don't want to steer someone wrong. Safest to stay with what I know will work. I wouldn't want to kill someone's switch planting. Stuffs to expensive.
