Did anyone get to use the new PreezePruf Spray prior to the cold spell? These would have been good conditions to test their claims.

Not that but we use allot of Anti-Stress 550..

I used the product on my 135 tree satsuma grove back in Dec before the cold weather arrived. I was out inspecting the trees yesterday and it appears that pretty much all of them are going to survive this cold blast. Most of the newer growth that came on late in the summer is burned but the central sections of all the trees appear to be healthy. I did use the micro mist sprinkler system on the trees as well so its hard to make a judgement on the product. I also have several seedling satsuma trees scattered around on the farm along with two trees at my home. None of them were sprayed with the product, neither did I use any misting or any other source of artificial heat. They all are alive and appear to be in somewhat better shape than the ones in the grove. My avg low temp for the first ten days of Jan was 22.1.. with two nights of 15F.. The average high for the period was around 41 F...This probably doesnt help you with an evaluation on Freezepruf but I did want you to know that I bought enough in commercial quantaties to spray my entire production.

Freeze-pruf is primarily made of propylene glycol, something that you can buy on the cheap from RV care centers. Even WalMart has them. They cost between $3.98 to $7.95 per gallon depending on the content of PG.

You can have a better concoction by mixing PG and KMag and water for your spray, and probably 1/10 th the price of FreezePruf for the same effects. But I wouldn't eat the rinds of the citruses and the leaves of vegetables sprayed with PG or freeze-pruf, even though it is labeled as non-toxic. It would taste awful.

Joe, that is very interesting. I'll have to give your formula a try. We stock propylene glycol in 55-gallon drums, along with various other glycols. I wonder how Glycerin, which is another glycol, works. If Glycerin also works, it would be even cheaper, as we stock it also in 55-gal. drums. but in truck load quantities. Glycerine has a slower evaporation rate then PG. - Millet (1,091-).

Now don't tell that even better secret Millet. FreezePruf is primarily PG plus K and Mg. PG is used for winterproofing marine and RV water lines. Glycerine is food grade while PG is labeled non toxic. But trace amounts of PG in the water lines will make the water taste bad how much more when applied to fruits. Glycerine would be better for fruits and veggies but mix it with surfactant.

I fail to see how anti-freeze types of products would help protect plants, unless they actually penetrate the tissue and (literally) serve as an anti-freeze inside the leaves, stems, etc.

If they are just on the surface, the liquid won't freeze, but the temperature will still drop below 32F. And there will be no benefit from releasing the heat of phase change like the benefit of spraying water on a tree to keep it at 32F and prevent frost damage.

You are correct that such products will not work with fruits. These prodcts can easily penetrate the leaves and outer layers of the tender stems or young barks. It cannot penetrate deep enough and besides you wouldn't eat a chemically altered fruits as I have pointed out earlier. The leaves especially on the top canopy is most susceptible to frost and that is the main target of the product.

Joe is correct about the ability of glycols to penetrate the leaves. Our farm uses glycerin (a glycol) to preserve cedar and oak branches. When the cedar and oak foliage absorbs the glycerin, the branch becomes "preserved" and therefore stays as naturally soft and playable as it was when they were still attached on the tree. After preserving, we sell them to the wholesale florist, potpourri and Christmas wreath market in the US, Canada, Europe and South America. We preserve approximately 5,000-lbs. per week. NOTE: a glycerin preserved branch can be put into the deep freezer for weeks and will not freeze. It remains just as soft and unfrozen as the day it was put into the freezer. - Millet (1,089-)

Folks, I seldom have the opportunity to comment on web forums, but just to clarify a few things in the recent threads on FreezePruf. First, the major cryoprotectant is polyethylene glycol, NOT the ethylene glycol used in car antifreeze. PEG is already present in many food products and medicines as a stabilizer, emulsifier, etc. In FreezePruf, it pulls water out of cells in a non-destructive fashion (cytorrhysis) thus lowering the freezing point of cell interiors. The small amount that gets in cells helps stabilize cell membranes against ice crystal damage. The cell-exterior PEG also reduces the freezing point of extracellular water. Glycerin acts as an intracellular cryoprotectant, and yes, the silicate formulation strengthens cell walls and the anitdessicant not only prevents water loss but also seals the formulation in the leaves/flowers/fruit for 4 - 6 weeks. The high-activity surfactant we use ensures that formula rapidly enters plant tissues and does nots aty on the surface.

The combination of ingredients produces better effects than any single ingredient alone. It took 6 months of tinkering with the formulation to get it right.

Our patent app had quite a bit of citrus data in it - it will add 2 -3 F to the survival temp of foliage and flowers. I have used it in the field with Satsuma mandarins here in Tuscaloosa, AL, and little damage to foliage and ripe fruits down to 17F on multiple nights (although at 15F, 15 MPH winds, and 36 consecutive hours below freezing I did finally see major defoliation).

I completely understand the concern about lack of peer-reviewed papers to date on F.P. I do have a major article ready to submit to HortTechnology, but frankly we did not expect the Liquid Fence people to bring the product to market so promptly.

I've since worked on mature tangerine fruits (as well as strawberries and tomatoes). F.P. does NOT prevent ripe tangerine fruits from freezing; rather it seems to reduce the damage when they thaw (e.g., 15 - 40% more viable fruit - - 16F freeze events ranging from 3 to 6 hours). In tomatoes, it reduces freeze injury (split skins, necrotic spots) at temps down to 25 F for 2 - 3 hours.

Again, ALL the ingredients in F.P. are approved for use on human edible crops - that was part of the formula design AND the state regulatory approval process. And there are NO off-tastes to the fruit when used as directed.

This mature fruit work will be submitted to HortTechnology as well.

I know Mark Russell, who heads GrowTech-sm, the parent company that FreezePruf is licenced to, has spent a lot of time in Florida this winter working with citrus, tomato, strawberry growers, etc. to get some early adopters to try it out on small sections of their crops. We have noted encouraging results to date.

We do feel the product has much to offer - NOT miraculous claims, but yes, I do believe we can give you a few degrees extra protection and can increase the amount of viable fruit you can harvest after a freeze.

But in the end, that's a call only the growers can make. We invite you to try it out and let us know.

While I can't promise to visit this Forum on a regular basis, I'd be happy to respond to email queries promptly (dfrancko@ua.edu).

Best,
Dave Francko
The University of Alabama
Tuscaloosa, AL 35487