Use of Insecticidal Soap as an Emulsifier?

[Ross]

I'm looking to improve the effectiveness of a pyrethrin concentrate (Pyreth-It) by adding an emulsifier, but have heard not all dish soaps are good for plant leaves. Any conjecture on using Safer Insect Killing Soap (49.52% Potassium Salts of Fatty Acids) in a mix with the pyrethrins?

 

[likespaphs]

have you thought of getting an adjuvant (i.e. sticker/spreader) like capsil?

 

[Ross]

have you thought of getting an adjuvant (i.e. sticker/spreader) like capsil?

That's a product I'm not familiar with.

 

[likespaphs]

it's a non ionic sticker spreader
i use it regularly but at about half the recommended rate. i do not believe i have used it much on orchids.
there has been occasional phytotoxicity with some other plants (i noticed weird growths on some Drosera as well as other fairly minor issues). i was not able to attribute the phytotoxicity to any other factors so i kinda think (but have no actual proof) that it was the Capsil. after that, i've lowered the rate to 1/2 recommended and not seen any additional issues.

http://www.aquatrols.com/greenhouse-and-nursery/greenhouse/products/specialty/capsil/?LOCALE=USA

 

[Ross]

Thanks, Brian!

 

[PaphMadMan]

The Safer's soap should work just fine as a test - no harm and it will have much of the effect of a spreader/sticker product. Physan 20 or a similar product would work too. Some spreader/stickers can have phytotoxic effects on their own, or may increase the toxicity of other compounds, so use with care until you know how your plants will react. I wouldn't expect a problem with pyrethrin though.

 

[Ross]

Thanks, Kirk. Because I have both on hand, I'll try a test plant today and see what happens.

 

[SlipperFan]

I have used Safer's soap with an insecticide/miticide to help it stick, no problems that I could see.

 

[Ray]

If I'm remembering correctly, ALL liquid soaps are potassium salts of fatty acids, whereas hard soaps are sodium salts.

I am curious about the "not all dish soaps are good for plant leaves" comment. Can anyone share info on what may be the issue?

 

[PaphMadMan]

If I'm remembering correctly, ALL liquid soaps are potassium salts of fatty acids, whereas hard soaps are sodium salts.

I am curious about the "not all dish soaps are good for plant leaves" comment. Can anyone share info on what may be the issue?

Liquid soaps just have to contain enough water. You can achieve this with sodium salts of fatty acids but only with a much lower ratio of soap to water that potssium salts. Commercial liquid soaps are generally potassium salts.

It used to be that dishwashing liquids were fairly simple products - a detergent, a coloring agent, maybe a thickening agent, and water. It was generally safe to use such a product as a spreader/sticker in pesticide solutions for small scale use. Increasingly these products contain several harsher surfactants in addition to the detergent, more likely to strip natural wax from leaves for instance, and also bleaching agents and preservatives with definite phytotoxicity, etc. And most don't give you a full ingredient list so you can't even be sure if/when a formulation changes on a product that has been safe.

 

[Leo Schordje]

I've used Safer's Insecticidal Soap as a spreader sticker for years. No problems. Since you have a large collection, consider also adding Enstar II to the Pyreth-It solution. It will definitely improve effectiveness.

 

[Potterychef]

Hi Ross, I have used the regular recipe Palmolive soap for years and it works well for me with no ill effects. Doug

 

[Ernie]

Regular formula of Dawn dish detergent is my preference. A teaspoon or two per gallon as a spreader has worked for us very well. Some recommend it at 2 Tablespoons/gal as a stand alone insecticide.

 

[etex]

Glad to see Dawn and Palmolive on the approved list!! That's what I use!

 

[PaphMadMan]

Just another caution to anyone using dishwashing liquid on plants as a spreader/sticker product. It may have been perfectly safe for many years and may be for many years to come, but formulations do change with no obvious change in packaging or labeling, and some definitely contain harmful components. Perhaps it is a very small risk, but for less than the cost to replace one plant why take any risk at all? There are safe, effective, inexpensive products out there meant to be used on plants. Almost everyone who is using pesticides already has (or should have) Safer's Soap or Physan 20 or similar products, and this use takes only a few drops.

 

[lindafrog]

I keep using Dr. Bronner's peppermint soap. Be careful with physan it can burn the delicate root tips on pluerathallis. I learned this one the hard way :-(