I just might have messed up

[TurfPro]

The other day I decided to kill some weeds right next to my temporary winter Ryegrass by using Atrazine. I read & re-read the label and found NO INFO on leaching etc....now,after doing a search here, I find some people have experienced problems with Atrazine being VERY MOBILE in the soil....have you found that to be true?

Does anyone know what the residual is on this product? Please reply if you do.
Thanks

BTW: Atrazine is not restricted use around here,you can buy it anywhere.

[TurfPro]

I forgot to mention it wasn't a big broadcast application,it was just spot sprying weeds. After doing some more reading though,I may still remove the 1st 1/2" of soild in the treated areas.....any thoughts?

[SWD]

Turfpro,
As long as you followed the label directions for application amount, Atrazine should not be mobile in the soil.
As far as residual is concerned, the label that accompanied the Atrazine I purchased, recommends a four to six week wait on reseeding.
What you will find is that with lower soil temperatures, most herbicides have a somewhat, 2-4 week, additional residual until the microbes become more active. Also, higher N levels from maintained turf tend to limit residuals as microbes tend to remain more active - so if you have been fertilizing more frequently with correct N forms, residual should be in line with the label.
Not knowing the site you sprayed, check any ornamentals bordering the spray site for phytotoxic responses. This can be foliar discoloration, sudden defoliation, obvious 'damage' symptoms. Also check the roots for discoloration - this is actually your best indicator, as well as mass reduction.

[TurfPro]

Thanks Steve

[Ric]

TurfPro

Atrazine's soil residual depends on the soil type as well. In my area sandy soil is the rule. Therefore it leaches quicker. This has to do with the lack of microbes and CEC. Atrazine is a surface and ground water poison. If you read the Label a little further you will see it should only be put down twice a year. Atrazine was taken off the market because of this, but it was let back on the market because of special needs. There was no other chemical that could replace it.

As far as tiring to remove the top 1/2" of soil, I wouldn't. It was only a spot treatment. If you see the discoloration That SWD mentioned it is to late to do anything. Some plants will work there way through this stress and come back others will die. Turf Herbicide stress to ornamentals is a common occurrence. (One time on LS a college student posted this question from a take home test he was stumped on.) Remember Trees and shrubs are broadleaves. Atrazine is a broadleaf herbicide. Atrazine is not mobile in the soil like 2-4-D but tree and shrub roots extend into turf areas. I have not looked at an Atrazine label in a while but I think it says not to apply near citrus trees etc. I have had calls from homeowner's about there citrus trees. I find a rich, weed free turf around a trunk and twigs with very few leaves. First question is how often do you put down weed&feed. I tell them to fertilize and water the tree. And then just hope it will come back.

[Tony Harrell]

Could someone expand on the special needs issue?

[TurfPro]

Ric,

Thanks for your input. I read the complete label ,,,more than once,and it made no mention of any of these side effects.... It is "Hy-Yield " brand. I've noticed that brand tends to be real sparing when it comes to info and pruduct use on their product labels.

Thanks again

[Ric]

Originally posted by Tony Harrell
Could someone expand on the special needs issue?

Tony The EPA allows certain chemicals to be used in certain area. But they do not allow these these chemicals to be used in all area. This can be marked on the label under the term SLN or special local needs.

"Applying Pesticides Correctly" is the CORE book here in Fla. and other states. It can be very dry reading. But it has a wealth of information. I think it can be purchased from Amazon.com pretty cheap.

[TurfPro]

"Applying Pesticides Correctly" is the CORE book here in Fla. and other states. It can be very dry reading.

"dry reading",,hehe that's a nice way to put it. I just got done taking my app test,,,it was VERY "dry" also ;)

[Tony Harrell]

I have my T&O license and I understand about labels but, I was wondering about the special conditions this product was brought back for. Oh yeah, GO RAIDERS!

[Ric]

Tony

Atrazine is the most widely used A.I. in weed and feed on southern turf. It is cheap to buy and even cheaper to make. There are no other herbicides that work as well as atrazine on southern turf. It was the chem. companies with there big bucks that brought it back. They also reformulated it from an RUP to a GUP.

[Weedburner]

Atrazine is commonly used by corn producers around the country. It is a good broadleaf herbicide and is often tank mixed with other chemicials when used as a post treatment. It can also be used as a preplant and incorporated in the soil. I don't think it has ever been removed from the market as an Ag chemical. There has been issues with it showing up in ground water. The carryover concern on the ag side is planting soybeans following treated corn the following year. If you didn't way over due the rate I don't think your grass will have much problem. If you didn't see the grass burnt from application drift you should be OK.

[Ric]

Weed burner

Interesting info. Thanks I am sure you are aware that Corn (a monocote) is in the grass family were as Soybeans (a Dicote) is not. The hardpan soil of the grain belt has more clay and SOM than my Fla sand. Hardpan will hold chemicals longer. I can see where atrazine could be a real problem in crop rotation.

Farmers’ use 90% of the fertilizers and chemicals that are mfg. Therefore R & D done by chemical companies is for farmers. We in Horticulture get the left over. The next time someone says farmer, remember that is a sign of respect even if they didn't mean it as such.

[lawnstudent]

Originally posted by TurfPro
....now,after doing a search here, I find some people have experienced problems with Atrazine being VERY MOBILE in the soil....have you found that to be true?

Does anyone know what the residual is on this product? Please reply if you do.


From the U.C. Davis ETOXONET web site I obtained the following information on Atrazine:

Atrazine is an EPA restricted use pesticide because of the high risk to ground water contamination. It is the second most prevalent pesticide found in well water.

Atrazine has a high persistence in soil. It will break-down more slowly in neutral pH soils. It can persist in soils up to 1 yr. if the soils are dry or cold (less microbe activity to break down this pesticide). It has a moderate to high mobility in soils with low clay or organic matter content.

Atrazine's half-life is high relative to more modern pesticides. Its half-life is 60-100 days (half-life is the time for 50% of a pesticide to decompose).

Hope this helps!

jim