I’ve been using Dyna-Gro Pro-Tekt nutritional supplement ( 0-0-3, with 7.8 % silicon dioxide )  for years to harden off green wood before the New England winter  http://www.greenhousemegastore.com/product/dyna-gro-pro-tekt-0-0-3/liquid-fertilizer   It works really well – the green branches start turning brown very quickly. I usually start treating the figs in August or early September.  Besides enhancing hardiness, Pro-Tekt is supposed to make a plant less susceptible to fungi by strengthening the cell walls.  So, this year I decided to try it on some of my fig trees that have had a constant problem with fig rust.  These included the Brunswicks (Jack Thomas’ Quarter Pounder, Joe Morle’s White Paradiso, Crazy Leaf Greek), Slocan, Nordland, and Stella.

Jack Thomas’ Quarter Pounder leaves showing fig rust

 I started treating the trees in June before any rust started, watering with a low concentration (about 1 teaspoon per 2 ½ gallons of water) and treated again in July and August.  It worked!  The foliage was much improved over previous years - but an unexpected result showed up as the figs started to swell prior to ripening.  No splitting!  The Brunswicks have always had a problem with splitting - rain or no rain.  Last year, I don’t think I got more than one or two that didn’t split.   And the splitting wasn’t limited to ripe figs.

Unripe Jack’s QP splitting

 On September 1st, we had about an inch and a half of rain.  I took this picture on September 2^nd when I picked 7 Brunswick figs –  and not one had split open!  Note the clean foliage.

I don't know what mechanisms are in play.  I was told that Pro-Tekt acts as a conduit for other nutrients - helping them to be absorbed by plants.  Cracking in tomatoes has been linked to lack of calcium and sudden increase in available moisture.  This article from the University of Georgia has a chart that shows the pH ranges where specific elements are picked up by plants. http://extension.uga.edu/publications/detail.cfm?number=B1256  

Is splitting in figs also due to the combination of lack of calcium and an increase in moisture?  Is silicon somehow making calcium more available to the tree?  Does the silicon make an end run around the pH requirement the way chelated minerals are absorbed more readily than their normal counterparts outside of the optimal range?  I tried to find more information, but while silicon has recently caught the attention of researchers, they still don’t seem to know how it works.  This is a simple overview from Pro Mix. http://www.pthorticulture.com/en/training-center/role-of-silicon-in-plant-culture/      Most sources don’t even list it as an essential nutrient.  So why does adding a bit of silicon make such a difference?  I don’t know.  I don’t have any answers – just observations, guesses, and questions.

It seems to me, that if the addition of a nutrient “cures” a problem, that problem was the result of a deficiency.  Adding DynaGro Pro-Tekt helped with both fig rust and splitting.  I know how strange that sounds.  What makes it even stranger is the very low concentrations of Silicon used.  I have a fertilizer injector, and am very conservative with chemical solutions.  When I first started using ProTekt to lignify the green wood before winter, I mixed the concentrate at half the recommended amount. But I noticed that the leaves of the Black Weeping Figs twisted.  So, I cut down on the amount.  To treat the trees in the fall, I now only use 1 cup (8 oz.) ProTekt to 5 gallons of water in the injector set at 1:100.  (One gallon of concentrate makes 100 gallons of fertilizer.)  The recommended concentration is 8-10 oz. per gallon.  That would be 5 – 6.25 cups at the recommended rate – not the 1 cup I use.  The recommended rate using a watering can is ½ - 1 teaspoon per gallon.  I hand watered the figs mentioned above since there weren’t too many, and only used 1 teaspoon for 2 ½ gallons of water. 

The directions say you can mix ProTekt with other nutrients by putting it into the water first, before adding other fertilizers.  I’ve done that – and ended up with precipitate in the bucket.  I would recommend using it alone.  And I would definitely start with low concentrations.  Though I do treat the figs a couple of times a week in the fall with no ill effects.  The article by Pro-Mix divides plants into classes determined by how they “accumulate” silicon. I don’t know where figs would be listed, but based on the reaction of my Weeping Figs, I’d start with low concentrations.

I hope anyone trying silicon will post their results. 

Thank you very much for sharing this. I got rid of my White Paradiso (Ed Morle) and was going to burn a large Sal's Corleone as the splitting was just too much to keep. I have tried treating rust with Serenade for years and do see some improvement but would really like a better choice. I do find that the more micronutrients (Azomite, bunny poop, seaweed and kelp and compost) I add the better the health of my orchard.

Mother nature does a great job taking care of in-ground plants.  We can only try to give our potted trees access to the nutrients they need - it's a complex system.  But what I saw last summer after using Pro-Tekt was a huge surprise - not so much the Fig Rust, but the splitting.  I don't know how much it will help in various circumstances, but I think supplemental silicon is definitely worth trying.

Well,
I'm going to see if it helps here. I'll let you know as I just ordered some.
thx

I use foliage pro already, but it doesn't seem to contain any silicon. I might have to try mixing in some silicon into my fertigation schedule.

Thanks for sharing fignut. I have a couple with rust and a Paradiso that splits. It is so tasty when it doesn't that I would like the possibility of more. 😋

They should give you a commission, your experience looks like it will give them more sales!

I just emailed Dyna gro regarding using protekt with foliage pro. I will update this thread when I get a reply.

Diatomaceous earth is mainly amorphous silicon dioxide, as far as I know anyway. I wonder if it would provide the same benefits as the Dyna Gro stuff?

Michael, I'm very interested in how this works for you.  I got these dramatic results last year, and will be treating this year - mostly for the effect on splitting.   I don't have a problem with rust - except for the varieties mentioned above.   Are your trees in pots?

livetaswim06,  The bottle says:  "Always use Pro-Tekt in conjunction with a complete nutrient formula, but never combine concentrates.  Always add Pro-Tekt to water first before adding other nutrients."  Even if Dyna-Gro says it's OK to mix, I think it would be a good idea to test on a small amount as the Pro-Tekt seems to cause precipitation rather easily.  Please do update!

doricdragons,   I didn't know diatomaceous earth was silicon dioxide.  It would seem that it would provide some benefits.  But one of the things that intrigues me about Pro-Tekt is how quickly it works.  I started using it to lignify green wood, and you could see the difference in one day.  Considering how slowly plants grow, that's light speed!  I use diatomaceous earth for fungus gnat control and put some on fig seedlings this past winter.  I didn't see any evidence that it was having an effect on the plants.  I recently started treating with Pro-Tekt as I'm going to be moving them outside soon, and I do see the little trunks browning up.

maybe there is something else in it that helps the plants take up the silicon. Horsetail weed contains silica and is recommended as a plant fertiliser.

The labeling rules are very strict in the US, so I don't think there is anything else other than what is listed.  In fact, I think it is the labeling rules that probably prevented them from listing the silicon as an "active" ingredient in Pro-Tekt.   The label says:  "ALSO CONTAINS NON-PLANT FOOD INGREDIENT: 7.8% Silicon Dioxide (SIO2) derived from Potassium silicate."  Years ago a salesman told me that Zero-Tol, a peroxide product, would explode fungus gnat larvae "like popcorn".  When I asked why that wasn't mentioned on the bottle, he said that they would have to do exhaustive studies ($$$) to prove it before they could make the claim on the label.

Silicon definitely helps, but I think the form it is in determines if the plant can use it quickly. While in-ground plants are growing in the stuff, they are still treating crops like rice and wheat with supplemental (immediately available) silicon products.  And in-ground crops are what is generating most of the research being done on silicon.

I’m grateful to Joe Dewhirst for researching and sending me this article,  The Influence of Foliar Applied Silicic Acid on N, P, K, Ca and Mg.pdf    It answers some questions.  My gut feeling was that calcium was the element that the silicon was channeling.  I was wrong – it was potassium.  “Silicic acid partially improved the quality of field peas of variety Mehis: the content of Phosphorus and Potassium in field pea dry matter was higher in the silicic acid treatment than in the control treatment. The content of Nitrogen, Calcium and Magnesium in field pea dry matter did not differ significantly between treatments.”

Based on the above are we saying ProTekt is best applied to leaves directly? Has anyone been able to do a comparison between foliar application vs fertigation? 

I haven't tried it on foliage, but will - though probably not in a controlled experiment.  It works pretty quickly to lignify in the fall when watered into the pot.  It's interesting to think it might work faster on the leaves.

It sounds like it might be very helpful to cuttings that are leafing out. The silicon helps lock in moisture which keeps leaves from drying out the cutting. This effect also has a positive impact on plants in hot dry climates.