Splitting and Fig Rust - Symptoms of Nutrient Deficiency??

[fignut]

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/p...uid-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,last 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 9-27-08


On September 1st, we had about an inch and a half of rain. I took these pictures 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/publication...m?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/tra...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 Dyna-Gro 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 Pro-Tekt 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.

[randy/ga]

quite intriguing.............randy/ga

[AscPete]

Thanks for sharing your observations and info. looking forward to your future results.

Have never tried Dyna-Gro Pro-Tekt, but I tend to have an aversion to unproven "Supplements", also Silicon occurs naturally in most soils, composts and potting mixes made from Peat Moss and Pine Bark. I tend to be skeptical of the "Ingredients" and instead look at and consider the "Active" ingredients of these "Supplements". For example the active ingredient is readily available Potassium (K @ 3.7%), http://www.extension.umn.edu/agricul...production.pdf

My observations for potted fig culture has been that increasing all the available Essential Nutrients, including the Secondary and Micro Nutrients increases overall plant health, leaf thickness and better fig development, https://www.ourfigs.com/forum/figs-h...s-in-fig-trees . Also Increasing Calcium appears to reduce or eliminates brown spots on developing figs, similar to the way it stops bottom end rot in Tomatoes, but the nutrients still have to all be available at the same time per Liebig's Law, http://soils.wisc.edu/facstaff/barak...6/lawofmin.htm .

[drivewayfarmer]

I'm with Pete ,I have a general aversion to unproven supplements , but in this case having used Pro-Tekt for years to harden off wood here in cool NH in preparation for Winter especially in my potted figs , I can say it works very well.
For young trees that just don't want to stop growing as it cools off in Fall , it quickly helps "ripen" a large part of the green wood.
I use it at even a lower rate than fignut , I think , just 1 tsp to 5 gallons of water which I water in , I never have used it as a foliar spray. Perhaps it takes longer than otherwise , but the wood ripens pretty quickly compared to untreated potted fig trees.
My understanding is that regular potting mixes for the most part have very little available Silicon and it has been a debate for quite a while in Ag circles whether it is important or not , but recently Black Gold has been putting available Silicon into their mixes as well as other companies.

http://www.greenhousemag.com/article/gmpro-0610-silicon-plant-growth/

In my farming days the best greenhouse cucumber growers I knew were using it because they saw very good anti fungal effects and lowered insect pressure.
The fact that fignut has noticed help with splitting and rust has me interested in paying attention to that.
For a foliar spray with silicon I use tea made by boiling for 20 minutes dried mature Equisetum arvense plants , 1 cup of dried herb to a gallon of water.
Looking forward to you updates this season fignut !

[Rafaelissimmo]

It is my understanding that Fafard 52 (which I use) new recipe as of last year contains some granular silica, maybe that will help for containerized figs?

[AscPete]

One of my primary potting mix ingredient is Calcined Clay which is 10% - 15% Silica...

[eboone]

Is that silica bound in the granules or released? In other word is it available to the roots in a form that can be absorbed?

[AscPete]

Its mostly available as Crystalline Silica which is broken down (over time in soil) into Silicic acid which is absorbed by plants.
Adding compost with plants that are "Silicon Accumulators" and or small amounts of Food Grade Diatomaceous Earth can also increase available Silicon.

[fignut]

The research around supplemental silicon is for in-ground plants – rice, wheat, etc. These are plants that have free access to silicon – they are growing in it. That suggests that the silicon isn’t in a naturally available form in large amounts. And even though Potassium Silicate is listed as the “active” ingredient with Silicon Dioxide listed as a “non – plant food ingredient” in Pro-Tekt, I can verify that the silicon is pulled into the plant very quickly. My original use - to lignify the green branches - is fast, and visible. It isn’t the potassium turning the branches brown. Is Fafard’s “granular silicon” a handful of sand for marketing purposes – or a form the plants can quickly use?

Pete, I understand that a healthy, well fed, plant is much more likely to resist insects and disease, and adding a supplement shouldn’t be necessary. I have a ton of figs, and I do my best to keep them healthy – but while using commercial mixes and fertilizers. For the most part it works, but it’s interesting that different varieties react differently to the exact same treatment. I don’t have a problem with Fig Rust – except for the above listed trees.

It stunned me that two serious fig problems could be helped with a few teaspoons of a substance that wasn’t even listed as an essential plant nutrient. But will the Fig Rust results be this dramatic in Florida, where the disease pressure is much heavier? Can a dose of Pro-Tekt keep all ripening figs from splitting after a heavy rain? I don’t have the answers, but I sure think it’s worth investigating.

[AscPete]

Not disputing the research results, but the "Positive Benefits" of Supplemental Silicon in much of the published documents has been tests with Potassium Silicate (additional available K), studies where K was not added shows minimal positive benefits. If Silicic Acid supplements alone were used in the trials I would be more accepting of their results.

[figwood1]

Thats really interesting!!!

[JMS]

Reallyninterested in this experiment. I have 3 brunswicks one of which is in the ground. I love their flavor but I would say half of them split or worse. Not sure what to do.

[AscPete]

I'm not disputing the possible benefits of Silicon in Dyna-Gro Pro-Tekt, just pointing out that the benefits that are attributed to the available Silicon are the "proven benefits" of Potassium (K),

Pro-TeKt 0-0-3 The Silicon Solution liquid supplement supplies higher levels of potassium and silicon to help plants build stronger cell walls. The stronger cell walls provide a Pro-TeKt-ive barrier against piercing-sucking insects and invading fungi. Applying Pro-TeKt 0-0-3 on a regular basis will minimize or eliminate the need for pesticides and fungicides. Additional benefits include increased stem strength and leaf positioning of plants, which improves photosynthesis; increased heat, drought and cold tolerance, plus longer lasting leaves and blooms. Use Pro-TeKt 0-0-3 as a supplement with any fertilizer to provide non-toxic preventative protection against fungal infections and insect infestations. Recommended for all plants.

[fignut]

I have to take back the cynical crack I made about Fafard in my last post. ("Is Fafard’s “granular silicon” a handful of sand for marketing purposes...?"). We use Fafard #3, and I checked a bag.The silicon is present as Calcium Silicate, another easily absorbed form. "Research shows that potassium silicate or calcium silicate can be injected..."

My bad!

[don_sanders]

I curious to see more updates this season.

This was an interesting read on silicon.

http://hightimes.com/grow/do-you-need-silicon-in-your-fertilizer-regimen/

I guess rice hulls may be an organic option to supplement silicon.

"Soil growers can also use silicates or silicic acid, but organic options also exist. If you mix your own soil, replace a quarter of the perlite or vermiculite you were already going to add with rice hulls. Rice hulls have a similar moisture holding capacity to perlite, but have no cation-exchange-capacity like vermiculite, meaning they should not completely replace perlite and vermiculite in the mix. Alternatively, a cannabis gardener could also compost rice hulls to make silicon-rich compost perfect for top-dressing soil."

[AscPete]

Or you could add DE (Food Grade) to the compost for the added supplemental Silicon.

[don_sanders]

Good point. I wonder if just sprinkling some on top of the pots would be an effective distribution method.

[AscPete]

More trials are probably needed to determine the effectiveness of Silicon additives, but the DE (which is > 85% amorphous, non-crystalline silicon dioxide - SiO2) should be composted or incorporated into the soil so that it can be transformed into a "plant available" form of Silicon.

[fignut]

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, and Pete was right – 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.”

When I started this thread about Pro-Tekt silicon solution a few days ago, I thought it was an obscure supplement. Apparently not – it seems to be the latest bandwagon. “As silicon nutrition reverses the succulence induced by high nitrogen and enhances crop growth and yield, silicon fertilizers based on silicate minerals, ashes and slags have come into vogue”. Who knew?

[jrdewhirst]

Thanks for the shout-out. I have two follow-up questions . . . .

Pete commented: " . . . the "Positive Benefits" of Supplemental Silicon in much of the published documents has been tests with Potassium Silicate (additional available K), studies where K was not added shows minimal positive benefits. If Silicic Acid supplements alone were used in the trials I would be more accepting of their results." So Pete was saying that the "positive benefits" from Supplemental Silicon derived from the potassium in the Potassium Silicate, not the silicon. If this is true, we could remedy the observed problems merely by adding some more potassium (e.g., potash).

I totally get Pete's alternative hypothesis, but I find it hard to believe that the plants in these experiments were grown in a medium deficient in potassium. And I am certain that fignut's trees are not raised in a medium that is deficient in potassium. So while accepting Pete's observation that the symptoms that fignut observed are symptoms of potassium deficiency, I was led to wonder whether (a) the problem might be absorption of potassium, and (b) the benefit may indicate that silicon facilitates the absorption of potassium.

If I read this article correctly, the experimental condition involved a foliar application of Silicic Acid, not Potassium Silicate. So that leads to Question 1, directed mainly to Pete: Does this experiment satisfy your condition, "If Silicic Acid supplements alone were used in the trials I would be more accepting of their results"? Granted it is only one experiment.

Next, I note that the application of Silicic Acid increased the content of both Potassium and Phosphorus. So Question 2: Doesn't this result suggest that the positive benefits of silicic acid result from better absorption of these available nutrients (not just the application of more potassium)?

[AscPete]

Joe,
I was not implying that the fig trees were "deficient in Potassium" just that the application of the Dyna-Gro Pro-Tekt Silicon Supplement included an additional amount of Potassium. Also the "Benefits" as stated in the sales literature are due to " higher levels of potassium and silicon"...

There are many experiments with Silicon on Crops and Greenhouse Plants, I prefer not to jump to conclusions on a reported ~ 6% increase in one study, but many studies have concluded that Silicon when present in sufficient quantity will increase root absorption of specific plant nutrients including Potassium.

[jrdewhirst]

I'm sure you know the research literature better than I do, so these comments apply only to what you wrote above: If a plant has disease symptoms that are alleviated by a supplement, the implication would be that the plant is deficient in something contained in the supplement. You may not have intended to imply a deficiency, but it could have been inferred. Correspondingly, I think a reader could read your messages above, taking away the message that rust and splitting could be cured merely by applying more potassium. And that silicic acid may be irrelevant. Anyway, that's how I read it.

I don't care too much about the specific language in the sales literature. They don't really know what does what, so they will use vague language to cover all bases.

I agree about the risks of jumping to conclusions based on one study. And I'm happy to hear that "many studies have concluded that Silicon when present in sufficient quantity will increase root absorption of specific plant nutrients including Potassium." My only remaining question would be whether some forms of silicon, being more accessible to the plant, are more effective than others. For example (and these are totally made up numbers), I'd rather have 1/4 oz of silicic acid or potassium silicate than 3 gallons of silicon dioxide (i.e., sand).

[AscPete]

Compost made with plants that are "Silicon Accumulators" and or small amounts of Food Grade Diatomaceous Earth (which is > 85% amorphous, non-crystalline silicon dioxide - SiO2) can also increase available Silicon,

http://www.siliforce.com/pdf/7c/Snyder%20Mati%20Les%20effets%20du%20Silicium.pdf

[AscPete]

fignut ,
This topic has has actually made me aware of the relatively large amount of silicon dioxide - (SiO2) that has been unconsciously added to my fig tree potting medium.

In addition to the Silica in the Calcined Clay which is 1/7 (~ 15% by volume) of my potting mix the trees and soil are dusted with DE at least two times per year and the dust is washed down into the containers.

Also my homemade compost with Chicken Coop bedding and manure has additional DE from the Roosts and Dust-baths.

[don_sanders]

I think I'm going to give the diatomaceous earth a try. Looks like it mixes pretty well with water so it should water into the soil pretty well and 40 lbs of Red Lake Earth Diatomaceous Earth with Calcium Bentonite is only $15-20. Food and feed grade. Maybe apply 1 cup per gallon of water and water with 200 ml of the mix per gallon of potting mix. Little less than a tablespoon per gallon of mix.

Might even try eating a little bit in case i have worms. Hah.

[AscPete]

I've tried the Red Lake DE, but now use and prefer Fossil Shell Flour its 100% DE,

https://www.youtube.com/watch?v=tBAWI8JFgrk

and it only costs $25 for 50lbs compared to $20 for 40 lbs of Red Lake DE at my local Feedstore.

[don_sanders]

AscPete Why do you prefer the Fossil Shell Flour?

I was a little concerned about not being 100% DE but the MSDS said it was 100% DE. I guess the calcium bentonite is naturally occurring in the source mine along with lots of other trace minerals which I thought might be beneficial. I guess it's the off white DE that I've read about?

Know anything about Safers DE. Says it's like 80% DE but didn't say what the rest is and I couldn't find out what it is searching around. Have a little bag of that lying around.

I haven't been able to find a source of 100% DE without bentonite locally yet.

[AscPete]

100% DE but what percentage of contaminants?...
The Fossil Shell Flour DE is Food Chemical Codex Grade which is "as pure as it gets" when it comes to minimal heavy metals and contaminants. On leaf surfaces the Red Lake DE leaves behind a thick red clay residue, while the Perma Guard DE (Fossil Shell Flour) leaves a light white film, when used as a dust, the same happens to the dusted animals.
I have no info on the Safer DE product, but I'm sure there's some info available on the Internet.

Red Lake DE ... 67% Amorphous Silica... http://www.absorbentproductsltd.com/...e-Earth-US.pdf
Perma-Guard DE ... 89% - 92% Amorphous Silica... https://www.earthworkshealth.com/wp-...ta.COA_FSF.pdf
Agrisilica SIRA ... 95% Amorphous Silica ... http://media.wix.com/ugd/73c92b_9209...6f211415bf.pdf

Agrisilica is mined silica that is marketed as fertilizer. They offer the Amorphous Silica (DE?) in three grades Powder, Granules (Pelletized) and Chip (Coarse). They have several videos and info linked on the website,

http://www.agripower.com.au/silica-silicon

http://www.agripower.com.au/agrisilica-fertiliser-trials

And, a site that re-packages the Fossil Shell Flour DE,

https://www.earthworkshealth.com/about-de/#1484247500281-c45dec40-41cd

https://www.earthworkshealth.com/diatomaceous-earth-products/

[jrdewhirst]

a little knowledge . . . .

I've tried to learn more about the "silicon accumulators," which include grasses such as wheat, corn and rice. So these crops tend to suck up silicon from soil and over time deplete the soil if the silicon is not replaced. Learning this, I am compelled to ask (1) whether the observed benefit of silicon supplements for such crops may relate to prior depletion of the soil; and (2) whether the research results generalize well to figs. Do figs have a high need for silicon? Maybe some varieties more than others? Maybe in-ground plants in good soil get all the silicon they need, while the inferred deficiency for some varieties could be directly related to the planting medium used for potted plants.

This does not argue against adding silicon, one way (e.g., DE) or the other (Pro-Tekt). But it may justify low doses, assuming that figs are not accumulators.

Along the way, I've learned that rice hulls are very high in silicon. So they could be a good additive, either unaltered or as char.

[livetaswim06]

If silicon is foliar applied and improves resistance to heat stress, low humidity and pests I think it's worth a shot. Since the silicon absorbs into the leaves and plumps them up, I am going to call this plastic surgery for my figs.

[Rafaelissimmo]

I would think Protekt used in a foliar spray would clog any sprayer, that stuff crystallizes and clumps ferociously

[livetaswim06]

I actually tried the foliar spray and it worked beautifully! I haven't seen much change quite yet but I would be surprised to after just one mild treatment.

[AscPete]

Some interesting info from a Commercial Silicon Fertilizer manufacturer in Australia,

http://www.agripower.com.au/silica-silicon

http://www.agripower.com.au/plant-available-silicon

.The actual benefits of added Silicon; note that some benefits are due to the physical characteristics of the product (SIRA), ie. "Improving Soil Structure",

http://www.agripower.com.au/soil-amendments-sira

[jrdewhirst]

Silicon in Soils and Plants - ResearchGate

For those with the interest, here's a great article on the role of silicon in plants. As implied by Pete's diagram above, the benefits are partly structural (as silicon is incorporated into plant stems and leaves), partly nutritional (as silicon compounds bind essential soil nutrients and reduce loss from leaching).

Silicon is absorbed by the plant only in the form of monosilicic acid, H4SiO4. So the accessibility of silicon to plants as a nutrient varies across silicon compounds and soil conditions, which determine the extent to which the specific silicon compound can be transformed into monosilicic acid. For example, crystalline SiO2, such as a quartz-based sand, is not readily transformed into the form that is accessible to the plant. Even so, silicon compounds that are only slowly transformed to monosilicic acid may still bind other nutrients, reduce loss from leaching, and promote nutrient uptake buy the plants.

These considerations have piqued my interest in the following possible additives to the planting medium:

a. Certain minerals such as glauconite (greensand) and wollastonite, comprised of various metal silicates. Deferring to Pete, maybe I should add silicon rich clays.

b. Biochars and composts made from silicon-rich plant materials, such as (i) rice hulls and (ii) the stems of grassy plants, such as bamboo, corn stalks, wheat straw. The "phytoliths" found in abundance in such plants are an amorphous (non-crystalline) form of SiO2.

c. Diatomaceous earth, which is basically comprised of fossilized, plankton-derived phytoliths.

d. Synthetic fertilizers, such as Pro-TeKt.

The relevant soil chemistry seems extremely complex, and I may have to read this article 3-4 times to understand the implications for potted figs. All comments from forum members would be appreciated.

[AscPete]

jrdewhirst

Joe, I plan on trialing the Fossil Shell Flour (Perma-Guard) DE,
https://www.earthworkshealth.com/wp-...ta.COA_FSF.pdf

Following the application rates and procedures posted at the Australian Fertilizer Manufacturer Nutri-Tech's website. It appears that "micronized" DE can be applied as a foliar spray and is "readily" broken down in the "soil solution". The Dia-Life DE has a median particle size of 5 microns and the Fossil Shell Flour is 10 microns (may have to increase the application rate slightly).

There are several other manufacturers in Australia and the USA selling DE as soil applied Silicon Fertilizer and the smallest median particle size is ~ 100 microns,
http://www.montanagrow.com/benefits.html

https://shop.nutri-tech.com.au/produ...a-life-organic
http://www.nutri-tech.com.au/factshe...fe-organic.pdf

'Dilute 1-1/2 Tbs (20 ml) per 1 gallon and apply the diluted mix at a rate of
1 quart per 9 square ft – this diluted mix can also be poured over foliage
Repeat every 2 – 4 weeks or as required'

BTW, I always have FSF DE on hand and the cost at my local feed store is ~ $27.00 per 50lb bag.

[ross]

Will any DE work? Or will you only be applying a silicon product as a foliar spray, Pete? This seems like a reasonable price: https://www.tractorsupply.com/tsc/pr...-40-lb-1052248

[AscPete]

ross ,
Most DE will work as soil applied, I've used the Red Lake DE for dusting, it has some clay byproduct which may add some additional nutrients.

The fine micronized DE may work better as a foliar feed due to the small particle size.

[jrdewhirst]

AscPete

That sounds great. To my untrained eye, it seems that diatomaceous earth may be a close substitute for the phytoliths naturally found in the earth as plant materials decompose. I assume that the micronized DE would be broken down faster. My only minor concern would be that you might see an impact only very gradually over a year or two, so the signal might get lost in other noise. Also, do you have to worry about breathing the DE "flour"? Thx.

[AscPete]

Yes, the micronized DE is broken down faster.

The finer particles would be absorbed faster and the larger particles would take more time, but the stated Silicon concentration in the soil solution is usually very small, only 100 - 120 ppm.

The Fossil Shell Flour has minimal Crystalline Silica which is the bad stuff, and is even sold for human consumption as a silica supplement. A dust mask is always advisable as with any "Dust" and or standing upwind when "dusting".

BTW If applied to the soil when fertilizing it would probably require less than 1/2 tsp per 5 gallon bucket.

[Rafaelissimmo]

Just an observation, Harvey suggested I add calcium supplement, I used Dyna-Gro Cal-Mag just ahead of Tropical Storm Harvey which came through saturday night here and I observed no splitting among various well known splitters in my collection.

[AscPete]

That's also been my observation and experience...

Increased Calcium, Gypsum and or Dolemite Limestone (relative to the usual recommended amounts) along with regular irrigation has resulted in minimal "splitting"

[Zuny]

This is a great tread lots of good information on here.