Looking for a wetting agent or surfactant that I can use in lieu of hort oil to help my trees get all that they can from the foliar sprays I apply. Three reasons: 1) Half my year is over 85 degrees, 2) If I used hort oil every time I’d like to help something spread and stick on my tree’s leaves, my yard might resemble the shores of Prince William Sound in 1989, and 3) some sprays solutions are just not compatible with or recommended to be accompanied with oil.

I do not want to use dish soap.

Only straight up surfactant that I can find in manageable quantities is this (it is labeled for use on citrus):

Label: http://www.rrsi.com/index.php?act=products.label&id=299&n=RedRiver90
MSDS info: http://www.rrsi.com/index.php?act=products.msds&id=299&n=RedRiver90

The active ingredient is: Alkylarypolyoxethylene glycols free fatty acids………..….……….….90%

Questions:

i) What are Alkylarypolyoxethylene glycols free fatty acids exactly?
ii) Does anybody know if this stuff will act as an accelerant to the sun’s rays as hort oil does?
iii) Anybody have an idea of an appropriate application rate – I was thinking ¼ teaspoon per gallon?
iv) Is it ok to add this to my hort oil sprays and would it help them to spread better than they already do?

Thanks and best,

Skinn30a

I would suggest that you talk to a local nursery to see what they do when they spray. You might do well to use Ivory or Dawn dish washing detergent. A local farm feed and seed store would have a non ionic surfactant in one gallon jugs but I don't know what a non ionic surfactant is. You are correct that some chemicals are not recommended for use with a prime oil type surfactant. It can cause severe burn with some products especially at higher temps. Of course always read the label.

Without going into a lot of chemistry (which almost no one would understand anyway) you can think of the chemical you are posting about as a non ionic detergent. Why would you want to add the surfactant to a Horticultural oil in the first place? Horticultural oils are not accelerants of the sun's rays. The reason that Horticultural oils (or probably also surfactants) are never used during the heat of the day, or when the temperature is high, is because oils and surfactants coat the surface of the leaf and therefore reduce the leaf's transpiration, therefore reducing the leaf's ability to cool it self. They do not accelerate the intensity of the sun's rays to burn the leaf. Further the high grade and purity of a good Horticultural oil evaporates quickly enough so that the normal leaf transpiration can soon continue thus avoiding any damage to the foliage.

The surfacant you post about should be fine to use at the rate of approximately 1 teaspoon per gallon. However, no matter what you use when spraying a citrus tree I would never recommend spraying during the heat of the day, its just not a good practice . I personally use a food grade surfactant called Tween-20 (Polysorbate 20). Commercially it is a food grade surfactant used as a wetting agent in cake mixes, and many other types of food products, flavored mouth drops such as Ice Drops, helping to provide the spreading feeling of ingredients like mint flavor, - Millet.

Alkylarypolyoxethylene glycols free fatty acids are the non-ionic surfactants that are commonly used in agricultural production and are similar to products like Safer brand insecticidal soap. Like Millet said, a non-ionic would be better on the plant than a hort oil. The most common that you can find at an ag chemical place would be an 80-20 surfactant. They are fairly cheap, normally costing less than $10 per gallon. Adding it at a .25% v/v concentration means that the gallon would yield 400 gallons of spray. For a small spray, use approximately 1-2 teaspoons of the 80-20 per gallon of spray.

A few rules with spraying surfactants:
1. Never use an oil based spray (hort oil, EC's) with a surfactant. This increases phytotoxicity.
2. Never use a foliar fertilizer or other products containing copper, with an oil based product. Also increases phytotoxicity. Plus foliar fertilizers use a nitrogen source to help with absorption.
3. Always add surfactants to the tank last.
4. Hort oils should be avoided when temperatures exceed 90oF and when the temperature falls below 40oF. Not only can they cause burn, but they can increase the risk of cold injury.

Blake

Dawn dishwasher soap works just fine.

Soap water mixes (as is Safer) do work. However, when spraying for scale or mealy bug it can often take 2 sprays and at times up to 4 sprays to obtain a complete eradication. A good Horticultural oil like Ultra-Pure will normally accomplish the job with the first spray. - Millet

When I spray I always use Dawn, 1 tablespoon per gallon, horticultural oil, 3 tablespoon in summer(and it is 90+ here all summer) and 5 tablespoon in winter and an insecticide like imidicloprid or spinosad. I also add some STEM to make um green up as well.

Thanks all. I always thought that hort oil accelerated the sun’s rays and caused burn on the leaf…as it would on my skin. I figured that by adding a surfactant to a hort oil mixture, that it would help the spray penetrate further into the cracks and crevasses that a larger droplet would hang-up on thereby increasing coverage and availability.

I’ll use the red river 90 surfactant in lieu of hort oil moving forward at a rate of 1 teaspoon per gallon when mixing my foliar sprays of Kocide 3000 (Copper Hydroxide), MgSO4, & KNO3.

Best,

Skinn30a