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VARMIT COMMISSION
04-29-2008, 11:33 PM
What's the minimum temp. you have used certainty to kill johnson grass and crabgrass in bermuda? And what is the highest temp. you have applied certainty to bermuda without injuring the bermuda?

tremor
04-30-2008, 12:34 AM
Never used it on Bermuda but for Bluegrass we're entering the period now in Southern New England. But NOT on Ryegrass.

Fall apps are often best AFTER a light frost here.

greendoctor
04-30-2008, 02:37 AM
I have no minimum temperature here. It works much slower for me when it is cool, cloudy and under 80 in the daytime. But I have used Certainty on warm season grasses provided the lawn is well fertilized and on an irrigation system at 90+. No problems. Herbicide injury is most likely when turf is under water or nutritional stress.

wrivers
04-30-2008, 10:49 AM
What's the minimum temp. you have used certainty to kill johnson grass and crabgrass in bermuda? And what is the highest temp. you have applied certainty to bermuda without injuring the bermuda?

I have never damaged turf at 95+ with Certainty, but I've never controlled crabgrass with it either, mostly becuase it doesn't control crabgrass at all. Maybe you meant nutsedge?

VARMIT COMMISSION
04-30-2008, 05:11 PM
Yes I did mean to say nutsedge. Certainty as far as I know wont kill crabgrass. What I want is a johnson grass killer that wont hurt my bermuda and MSMA just wont do it for me. Only temporary. From what I have heard 75 degrees is the coolest temp. to use it to get control of johnson grass and it takes 3 apps. to get it.

wrivers
04-30-2008, 05:45 PM
Yes I did mean to say nutsedge. Certainty as far as I know wont kill crabgrass. What I want is a johnson grass killer that wont hurt my bermuda and MSMA just wont do it for me. Only temporary. From what I have heard 75 degrees is the coolest temp. to use it to get control of johnson grass and it takes 3 apps. to get it.

I'd wait until you'll have at least 4 consecutive days in the 80s, then hit it with Certainty at 2.0 oz/ac and the MSMA together. That ought to put a wallop on it.

RobHawkins
04-30-2008, 06:29 PM
Where is the cheapest place to buy Certainty? I need to kill Dallisgrass. NCSU used it with MSMA and X-77 Spreader for a 98% final control in tall fescue. I have a yard full of Dallisgrass, but I can't find Certainty for less than $185 for a 1.25 oz. bottle.
Thanks,
Rob

PHS
04-30-2008, 11:11 PM
$185, wow! I was at Ewing Irrigation the other day and he told me $95. I've never used Certainty before but I also have it in my material cost spreadsheet as $94 from a while back when I was looking at it but for some reason I didn't enter the supplier.

Hoots
04-30-2008, 11:19 PM
Generally the warmer the temps=quicker kill. Definitely the same thing on your nutsedge. If you still have poa, like most of us do, it works wonders on that too. Most people go on 85+ temps. In the winter when we get some poa, we spray with Monument or Certainty (close to the same products) but it can take 4 weeks to yellow if the temps are not up above at least 50 in our case.

yardprospraying
05-01-2008, 12:55 AM
Just spray with 2oz/ac. rate and add a good surfactant. No need for msma. I would also tell your customer to wait as long as possible before they mow after the application. I usually tell them to wait at least 24-48 hrs before they water, and then wait 7-10 before they mow for the johnsongrass. I have never burnt a lawn and have sprayed it in 85 deg. temps. It might take a little longer in cooler temps, but it will get the "johnson's".

Certainty is a pre & post emergent, so once you get rid of whats up, you shouldn't have any more come up (as far as johnsongrass goes). On nutsedge, try to use as fine of a spray as possible, to contact more of the weed blade. If you are using the old chemlawn shower nozzle, you might not have very good results. We typically use a flat fan spray on our chemlawn guns to give better coverage. Since you have a new PG, you should be ok as long as it covers good. I can't say though heard a lot of good and bad about leaf coverage. We usually just spot treat with a backpack for the sedges though.

Good luck,


John.

hmartin
05-04-2008, 10:38 PM
I don't know what yall are calling johnson grass. If the lawn is mowed more than once a month, you are not going to have johnson grass in a lawn. Johnson grass grows up to 5 or 6 foot tall in a hayfield. Regular close will quickly kill it in a lawn.

VARMIT COMMISSION
05-04-2008, 10:47 PM
I live on an acreage. The guy next to me mow's weekly with a ride on not a brushhog and he has had johnson grass at his culvert for going on 8 years now. One of my customers uses a weedeater on his fence line weekly and has lots of it. I mow the field behing me and it never get more than 6" talll and it is almost all johnson grass. It will slow it down but it always comes back. Atleast for me it does.

yardprospraying
05-05-2008, 12:16 PM
I don't know what yall are calling johnson grass. If the lawn is mowed more than once a month, you are not going to have johnson grass in a lawn. Johnson grass grows up to 5 or 6 foot tall in a hayfield. Regular close will quickly kill it in a lawn.

Nice try!!!!!


I live on 8 acres, and I mow every seven days. I had spots of johnsongrass in it 4 yrs ago, and couldn't get rid of it by mowing. Pre-emergents typically do not help since johnsongrass is a perennial. It reproduces from seed and rhizomes, and it's roots are typically "deep" enough for it to survive most hard winter freezes.

This is just one of the many websites that explain about johnsongrass, just google it and you will find a lot of info.http://www.nwcb.wa.gov/weed_info/Sorghum_halepense.html

I treated my lawn 4 yrs ago with Certainty ( Sulfmeturon Methyl) at 2 ounces per acre in the early spring when it was starting to come up. I have not seen any johnsongrass at all where I treated until this year. I have one spot where there is a couple of plants trying to come up. I just spot treated them last week. In years past I have tried numerous times to get rid of it by spot spraying with glyphosate. It often wouldn't phase it, mainly because it the glyphosate doesn't get translocated to the intense rhizome root system that johnsongrass has.

There is also a glyphosate resistant strain of johnsongrass Arkansas and Mississippi. http://monsanto.mediaroom.com/index.php?s=43&item=580 It is something that we are going to have to deal with in the long term. We often think glyphosate is the "cure all" for everything, but it isn't always the "siver bullet". I feel that a lot of people do not use the proper rates of chemical, or do not "rotate" their treatments enough. If you always use the same product year after year, then their can be consequences. After all look at TG. They use the same product year after year, and never change the pre-emergents up. They have yards they have been treating for years that are "loaded" with crabgrass. They use the lowest rate of p-meth, and treat every yard the same way. We try to change our apps. every couple of years, so we do not have this problem.

BTW: We do vegatation manament (r.o.w.) on many oilfield locations and pipelines, and if it wasn't for Outridder (Sulfmeturon Methyl) and Krovar, we would be treating several times a year. We can now do one treatment, and be done with it until the next year.

John..

hmartin
05-06-2008, 02:18 PM
RECOMMENDED PRACTICES ON BUFFER AND SEVERELY DISTURBED SITES
Initial effort in areas of heavy infestation
Repeated and close mowing kills Johnson grass seedlings, prevents seed production, and reduces rhizome growth and regrowth of shoots.

hmartin
05-06-2008, 02:55 PM
I am sure you are right about the johnson grass, but I have never inspected a regularly mowed lawn that had johnson grass. I live in a rural area and it is everrwhere in pastures, CRP fields, and vacant lots. Just my opinion.

Turfdoctor1
07-26-2008, 12:42 PM
Nice try!!!!!


I live on 8 acres, and I mow every seven days. I had spots of johnsongrass in it 4 yrs ago, and couldn't get rid of it by mowing. Pre-emergents typically do not help since johnsongrass is a perennial. It reproduces from seed and rhizomes, and it's roots are typically "deep" enough for it to survive most hard winter freezes.

This is just one of the many websites that explain about johnsongrass, just google it and you will find a lot of info.http://www.nwcb.wa.gov/weed_info/Sorghum_halepense.html

I treated my lawn 4 yrs ago with Certainty ( Sulfmeturon Methyl) at 2 ounces per acre in the early spring when it was starting to come up. I have not seen any johnsongrass at all where I treated until this year. I have one spot where there is a couple of plants trying to come up. I just spot treated them last week. In years past I have tried numerous times to get rid of it by spot spraying with glyphosate. It often wouldn't phase it, mainly because it the glyphosate doesn't get translocated to the intense rhizome root system that johnsongrass has.

There is also a glyphosate resistant strain of johnsongrass Arkansas and Mississippi. http://monsanto.mediaroom.com/index.php?s=43&item=580 It is something that we are going to have to deal with in the long term. We often think glyphosate is the "cure all" for everything, but it isn't always the "siver bullet". I feel that a lot of people do not use the proper rates of chemical, or do not "rotate" their treatments enough. If you always use the same product year after year, then their can be consequences. After all look at TG. They use the same product year after year, and never change the pre-emergents up. They have yards they have been treating for years that are "loaded" with crabgrass. They use the lowest rate of p-meth, and treat every yard the same way. We try to change our apps. every couple of years, so we do not have this problem.

BTW: We do vegatation manament (r.o.w.) on many oilfield locations and pipelines, and if it wasn't for Outridder (Sulfmeturon Methyl) and Krovar, we would be treating several times a year. We can now do one treatment, and be done with it until the next year.

John..


i'm bumping this old topic back up because i have what i think is a major, and i mean major johnsongrass problem in a newly sodded zoysia lawn.

To be quite honest, i can't id it 100%. the lawn is being mowed about every 5 days, so the weed is not tall, and i have concluded that it must be either johnsongrass or barnyardgrass. i have never seen barnyardgrass and IDing these types of weeds at 2 inches is not easy. What makes me think that it might be barnyard grass is that it appears to have no ligule, but upon close inspection, maybe it is just very, very truncate. What would make me question it being johnson grass is that i cannot find a rhizome anywhere, it is being mowed every 5 days, and it is simply everywhere.

If it is johnsongrass, has anyone seen burn on zoysia with Certainty at temps in the high 90's? If no, can you expect to kill johnsongrass at that stage with 1 application of Certainty? I will run by the house and take some pics and see if i might get you guys to help me identify it. this pic is not much help, i know. any help is appreciated. thanks guys.

PHS
07-26-2008, 07:27 PM
Johnsongrass has an obvious light colored mid-rib which I don't see on that sample so I would tend to think that isn't JG.

Turfdoctor1
07-26-2008, 09:28 PM
Johnsongrass has an obvious light colored mid-rib which I don't see on that sample so I would tend to think that isn't JG.

thanks PHS. i really think that it is barnyard grass. it is just really unusual to see it.

i guess now the question is whether the zoysia sod can withstand an MSMA treatment next week when it is bumping 100 degrees. i vote no.

PHS
07-27-2008, 09:09 AM
I make MSMA apps on Bermuda when it's around 95 and it works very well. I've never sprayed Zoysia though.

wrivers
07-28-2008, 09:45 AM
thanks PHS. i really think that it is barnyard grass. it is just really unusual to see it.

i guess now the question is whether the zoysia sod can withstand an MSMA treatment next week when it is bumping 100 degrees. i vote no.

Barnyardgrass has purple stems and a prostrate growth habit as it matures, similar to goosegrass. It also has a very distinctive seedhead.

http://www.ipm.ucdavis.edu/NEWS/IMAGES/Barnyardgrass_flower.jpg

I take it out with Drive + MSO + MSMA. Fusilade II will work for zoysia as well, but it's not labeled for residential.