Crop oil and nonionic surfactants

[bigmike]

I'd like to learn about the differences. I always use nonionic surfactants and sometimes get mediocre results with Clethodim, for instance. Can we get a discussion going about this? Whats the difference and why do different products need different surfactants?

[Jef Hodges]

In my simple mind I differientiate the two like this, non-ionic surfactant makes water wetter and crop oil makes water stickier. The surfactant allows the water/chemical solution to spread across the surface more evenly and the crop oil causes the solution to adhere to the leaf surface better.

I've always gotten what I consider mediocre results with Clethodim and feel it is just how Clethodim is.

[shmoopy]

Clethodim calls for crop oil. You aren't getting good adherence with Non-ion Surf. That's why it's a poor result.

[hrcarver]

The short version as I understand it...

Surfactants increase coverage of a herbicide.

Crop oils increase penetration of a herbicide.

[Smallplot]

Originally Posted by bigmike

I'd like to learn about the differences. I always use nonionic surfactants and sometimes get mediocre results with Clethodim, for instance. Can we get a discussion going about this? Whats the difference and why do different products need different surfactants?

Check this link out.

http://www.weeds.iastate.edu/mgmt/qtr98-2/cropoils.htm

[Alpha Doe]

We generally use non-ionic surfactant when we are using it on something that we don't want to take a chance of burning the foliage of a crop. Maybe crops that will not produce or recover from the burn it may receive from crop oil. Like greens of flowers, trees or brassicas...things like clover will generally recover from foliage burn. At times, we use non-ionic surfactant even in our clover plots. We also use liquid AMS and always get a good kill of grasses.

With clethodim it is important to know what type of grass is your target grass. Different grasses require different rates. Many times mature perinnial grasses require higher rates than the 6-8 oz.

[whitetail fanatic]

Originally Posted by Alpha Doe

....With clethodim it is important to know what type of grass is your target grass. Different grasses require different rates. Many times mature perinnial grasses require higher rates than the 6-8 oz.

AD, didn't you say that for tough perennial grasses we should use like 16 oz clethodim per acre?

thanks

[Alpha Doe]

Originally Posted by whitetail fanatic

AD, didn't you say that for tough perennial grasses we should use like 16 oz clethodim per acre?

thanks

Many times mature perinnial grasses require higher rates than the 6-8 oz

When looking at the label you will find that 16 oz. per A is the highest rate. The rate is based on the type and maturity of the target grass. Perinnial and mature grasses may require higher rates than the 6-8 oz. that is usually recommended.

[Smallplot]

Originally Posted by whitetail fanatic

AD, didn't you say that for tough perennial grasses we should use like 16 oz clethodim per acre?

thanks

WF, take a look at the label when you have some time to read, it is a lengthy one. It showed numerous rates for various crops and target weeds. Remember if the target weed is at the optimum height you can usually use the lowest rate. If the weed is matured you should use the highest rate. Most herbicides have a total allowable yearly rate per acre which may come into play when you have to make multiple applications in a year.

If you find you are having trouble controlling any weed with the highest rate your target may have developed a resistance to that particular herbicide or you are not applying it at the proper growth stage of the target weed. In this case a switch of herbicides may be required.

Someone posted they believe Cleth calls crop oil. Look at the crop on the label and use the recommended Adj. For instance non-ionic Surfactant is listed for ornamentals, I believe.

[shmoopy]

"Small Plot" is right about the clethodim label... but for food plotting purposes it's hard to see where one would not be following the crop oil recommendations.

Also, cletho/sethox/etc. grass selective herbicides take some time to work, unlike glyo, so adjust your expectations accordingly.