Phosphite: What companies aren't telling you

[FONT=Times New Roman, serif] I wrote this after I heard a buddy uses Pure Flowers (phosphite) as a phosphorus (P) fertilizer for pre-flowering because of claims by Pure Flower company; and I know a few people on Icmag who use it, so I thought this could help them and others. This is in no way meant to be an insult or upset anyone who uses phosphite as a P fertilizer, I just hope to help explain and sort out truth from fiction from claims made by sellers/makers of phosphite fertilizers. This is not meant to be conclusive, it's only my take on what I have learned.[/FONT]

[FONT=Times New Roman, serif]Phosphites (Phi) are formed using phosphorous acid (H3PO3) that is neutralized to form salts and becomes phosphonate ions (H2PO3), also called phosphite. Often Phi is sold in the form of potassium phosphite (K2H2PO3). Normally P is supplied with fertilizers containing phosphoricacid (H3PO4), which is a form of phosphate (Pi) available to plants.[/FONT]


[FONT=Times New Roman, serif]What does phosphite do for plants?[/FONT]


[FONT=Times New Roman, serif]It is a systemic fungicide active against a few soil fungal pathogens and a few foliar fungal pathogens when used as a foliar spray additive (ex., PM). Phosphites are sold as fungicides by most of the AG companies yet some companies are being unethical when they label Phi as a P fertilizer.[/FONT]

[FONT=Times New Roman, serif]Foliar application of Phi has been shown to act as an 'inducer' for SAR (Systemic Acquired Resistance). SAR is a natural red-alarm mode for plants which can make grow bigger, faster and can increase yields and resistance to biotic attacks and environmental stress. Other products at the hydro store such as chitosan (as Chi), harpin protein (as Messenger and now Employ), salicylic acid (as Scorpion Juice) also activate the salicylic pathway acting as inducers for SAR. [/FONT]

[FONT=Times New Roman, serif]Even from just a single foliar application of Phi it has been shown that in many plants and trees “...it increases floral intensity, yield, fruit size, total soluble solids, and anthocyanin concentrations [ex., a source of color for purple buds], usually in response to a single application.” (Lovatt and Mikkelsen; 2006). Those responses could be due in part to induction of SAR by Phi. [/FONT]
[FONT=Times New Roman, serif]Phi has been found to supply P to P-deficient plants when Phi is applied as a foliar spray. Once taken in by the plant the mode of action is a bit surprising and not very well understood. Phi can't be used as a P source by the plant directly, even though Phi was absorbed into the leaf. There is some disengagement in the academic world whether or not plants can convert Phi into Pi; one side thinks it is possible but they can not prove it because they can not identify a potential enzyme or reaction for the conversion. The other side thinks it is not possible because no one can show what enzyme or reaction could convert Phi into Pi. The latter group makes the point that Phi, even after a single application, has been found to remain in plant tissue for over a year. The latter group claims plant usage of Phi once it is absorbed is low which is why Phi can become phytoxotoxic in concentration. That point is sound because Phi is systemic and stable once in the plant tissue.
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Microbes in the media (ex., rhizosphere) and the and on leafs (phyllosphere) can convert Phi into Pi and then the plant can use the Pi as a P source, this is how Phi is thought to benefit plants in terms of P; however that conversion is a slow process. Most microbes do better consuming Pi for energy than Phi. [/FONT]
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Plants given only Phi as a P source (in hydro or soilless) will become P-deficient in a short time. What this means is that Phi is not an adequate source for P. Phosphite can not replace Pi as a plant nutrient source for P; the P attained by plants from application of Phi to P-sufficient plants is very low.[/FONT]

[FONT=Times New Roman, serif]What does phosphite not do for plants?[/FONT]
[FONT=Times New Roman, serif]
Phi is not a replacement for Pi as a source of P in bloom boosters, that means products like Pure Flowers, if only using phosphite as the P source, will not preform as well as bloom booster with phosphoric acid or other Pi source for boosting P. Applying Phi during pre-flowering when the plant can use extra P (and N, K, Ca, Mg, etc) is probably the best time because plants can tolerate and can benefit from higher levels of P and K (more of the latter than the former). [/FONT]

[FONT=Times New Roman, serif]Phi can not replace Pi to provide P to plants even though the Phi and phosphorous acid contain higher levels of P (~39%) than Pi and phosphoric acid (~32% P). Phi is more water soluble than Pi and is absorbed faster into the respiration tissue (roots) or photosynthesis tissue (leafs). However, once inside the plant Phi does not provide P for the plant in sufficient quantity and can inhibit growth and health of the plant if overused.[/FONT]

[FONT=Times New Roman, serif]Phi is not a broad range system fungicide with a wide range of fungi it will inhibit. I for one am interested in using it as a pre-flowering bloom booster as foliar spray which might also help prevent occurrence of PM.[/FONT]

[FONT=Times New Roman, serif]Phi has been found to inhibit Pi uptake, probably because both Phi and Pi taken up by plants using Pi transports. Considering Phi is absorbed faster than Pi, it is possible Phi effects the Pi transporters ability to uptake Pi.[/FONT]

[FONT=Times New Roman, serif]Phi interferes and can inhibit with Pi starvation responses in plants, such as increased roots growth and increased root to shoot ratio, etc.[/FONT]

[FONT=Times New Roman, serif]How can phosphite hurt plants?[/FONT]

[FONT=Times New Roman, serif]Phi can cause phytotoxic conditions in plants when used in high concentration or used often. Using levels (ppm) of Phi that are the same as commonly used levels of Pi is suggested as the max concentration to prevent phytotoxicity, and not to apply often. However, applying Phi at rates (ppm) lower than Pi, especially as a foliar spray, seems the safest route. I think this is why usage rates for Pure Flowers and other Phi products is so low, excess Phi will cause phytotoxicity and sufficient Phi will not boost P like bloom booster with Pi.
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[FONT=Times New Roman, serif]Plants can self-regulate uptake of some ions such as nitrate nitrogen, P, Ca, Mg, etc. It is thought at least in the case of nitrate N and P that the level of certain amino acids in the xylem trigger the plant to stop or greatly reduce uptake of specific ions. This means the plant controls the uptake of some ions from the rhizosphere. I think this is good because a plant's nutritional needs changes over time and it would be hard (or impossible) to try and give a plant a “perfect” hydro fertilizer in terms of ppm of ions at all stages of growth each day. Letting the plant take care of it takes the work out it for us. However, if the ionic solution (fert water) is too rich I believe osmotic factors can bypass plant self-regulated uptake and cause phytotoxicity. [/FONT]

[FONT=Times New Roman, serif]An example of one cation which plants can not self-regulated uptake is ammonicial nitrogen (often sold as ammonium). Because plants can not limit up take of ammonicial nitrogen and because ammonicial nitrogen is taken into roots efficiently ammonicial nitrogen can cause phytotoxic conditions in the roots if the plant can't move enough sugars into the roots to keep up with conversion of ammonicial N for plant usage. It's possible that Phi acts in a similar fashion to ammonicial nitrogen bypassing the plants ability to limit P uptake, and because Phi isn't converted within the plant and has low usage rate by the plant it can become too concentrated and then cause phytotoxicity.[/FONT]

[FONT=Times New Roman, serif]Use of Phi could injure beneficial fungi in the media and phyllosphere. However, it was found Phi does not have a strong fungicidal effect on a broad array of fungi species in soil.[/FONT]

[FONT=Times New Roman, serif]How should phosphite probably be used?[/FONT]

[FONT=Times New Roman, serif]Phi should be used as a foliar spray in my opinion, only during pre-flowering. Spraying at most two times using weak solution at week 2 and then week 3 (before buds start forming), or spraying once at week 2 or 3 with a stronger solution might be the best option. [/FONT]

[FONT=Times New Roman, serif]Phi is readily absorbed though the cuticle layer into leafs, but use of a good non-ionic surfactant and 2.5-5 ml of CalMag+ per gallon of water will assist in cuticle hydration and swelling which increases absorption of other ions and organic substances into the leaf. Adding humic acid in folair spray is good because it prolongs the time the water droplets survive on the leaf (humic acid reduces rate of evaporation) and humic acid benefits the leaf in other ways too.[/FONT]

[FONT=Times New Roman, serif]If using Phi as a root drench (soilless, hydro, etc) including Pi will help mitigate some antagonistic effects of Phi upon Pi and Pi transport.[/FONT]

[FONT=Times New Roman, serif]How should phosphite probably not be used?[/FONT]

[FONT=Times New Roman, serif]Phi should not be used to replace Pi as the sole source of P in bloom boosters. Phi will not provide the level of P that Pi provides in terms of the P available to the plant. This is why plants given only Phi as the sole P source will become P-deficient and grow poorly. It is odd to me that Phi can simultaneously create P-deficient plants and plants suffering from phytoxicity. I believe if people see increased yield when using Pure Flowers it's probably from the K and not the Phi which offers little useful P to the plant. From what I have read in some forums (like here at Icmag) most people do not think Pure Flowers gives more yield than other good bloom boosters, YMMV. I for one will not be using Phi (like Pure Flowers) as a bloom booster replacement; I think I may use the potassium phosphite and potassium silicate product Green Speed Si (0% N- 2% P – 5% K - 5% Si) as a folair spray during per-flowering. [/FONT]

[FONT=Times New Roman, serif]Phi should probably not be used on a regular basis at concentrations equaling that used for Pi; application once every few weeks if used as a fungicide or as a SAR inducer; or one (max twice) during pre-flowing if using as a bloom booster. This in only my opinion after never using Phi (yet), so YMMV.[/FONT]


[FONT=Times New Roman, serif]References:

[/FONT] [FONT=Times New Roman, serif]Phosphite Fertilizers: What Are They? Can You Use Them? What Can They Do?[/FONT]
[FONT=Times New Roman, serif]C.J. Lovatt and R.L. Mikkelsen[/FONT]
[FONT=Times New Roman, serif]Better Crops/Vol. 90 (2006, No. 4)[/FONT]




[FONT=Times New Roman, serif]Phosphorous and phosphoric acid: When all P sources are not equal[/FONT]
[FONT=Times New Roman, serif]Asha M. Brunings, Lawrence E. Datnoff and Eric H. Simonne[/FONT]
[FONT=Times New Roman, serif]Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida; doc document is HS1010, April 2005[/FONT]




[FONT=Times New Roman, serif]Attenuation of Phosphate Starvation Responses by Phosphite in Arabidopsis[/FONT]
[FONT=Times New Roman, serif]Carla A. Ticconi, Carla A. Delatorre, and Steffen Abel [/FONT]
[FONT=Times New Roman, serif]Plant Physiol, November 2001, Vol. 127, pp. 963-972[/FONT]




[FONT=Times New Roman, serif]Phosphite, an Analog of Phosphate, Suppresses the Coordinated Expression of Genes under Phosphate Starvation1[/FONT]
[FONT=Times New Roman, serif]Deepa K. Varadarajan, Athikkattuvalasu S. Karthikeyan, Paino Durzo Matilda, and Kashchandra G. Raghothama[/FONT]
[FONT=Times New Roman, serif]Plant Physiol, July 2002, Vol. 129, pp. 1232-1240[/FONT]




[FONT=Times New Roman, serif]Effect of phosphite fertilization on growth, yield and fruit composition of strawberries[/FONT]
[FONT=Times New Roman, serif]Ulvi Moor, Priit Põldmaa, Tõnu Tõnutarea, Kadri Karpa, Marge Starasta and Ele Vool[/FONT]
[FONT=Times New Roman, serif]Scientia Horticulturae Volume 119, Issue 3, 3 February 2009, Pages 264-269 [/FONT]




[FONT=Times New Roman, serif]Transport and compartmentation of phosphite in higher plant cells--kinetic and P nuclear magnetic resonance studies.[/FONT]
[FONT=Times New Roman, serif]Danova, Dijkema C, DE Waard P, Köck M[/FONT]
[FONT=Times New Roman, serif]Plant Cell Environ. 2008 Oct;31(10):1510-21. Epub 2008 Jul 24.[/FONT]




[FONT=Times New Roman, serif]Phosphite Treatment: Treating Your Plants with Phosphite[/FONT]
[FONT=Times New Roman, serif]Dieback Working Group[/FONT]




[FONT=Times New Roman, serif]Bleeding Trees[/FONT]
[FONT=Times New Roman, serif]Annette Stark[/FONT]
[FONT=Times New Roman, serif]Ventura County Reporter[/FONT]




[FONT=Times New Roman, serif]Phosphites and Phosphates:When Distributors and Growers alike could get confused![/FONT]
[FONT=Times New Roman, serif]New AG Internatlation, September 2007[/FONT]
[FONT=Times New Roman, serif](indudsty publsion)[/FONT]




[FONT=Times New Roman, serif]A brief note about potassium phosphite on phytophthora[/FONT]
[FONT=Times New Roman, serif]Dr. Ilangovan Ramasamy[/FONT]
[FONT=Times New Roman, serif]Chief Scientist, Arborjet[/FONT]
[FONT=Times New Roman, serif](written by a coorpate sitcints but good info regless with refences to boot)[/FONT]



[FONT=Times New Roman, serif]Benefits of Tru-Foliar™ Fertilizers Containing Phosphite (HPO3-)[/FONT]
[FONT=Times New Roman, serif]Grigg Bothers Foliar Fortilzers[/FONT]
[FONT=Times New Roman, serif](written with good info and some reces but ti's a brodcouhre for their prouct but has good pics of Phi vs Pi vs control as a fertlizer)[/FONT]


A critical assessment of the suitability of phosphite as a source of phosphorus
Arne M. Ratjen1, Jóska Gerendás
Journal of Plant Nutrition and Soil Science, Volume 172, Issue 6, pages 821–828, December, 2009


Effect of phosphite phosphorus on alfalfa growth
K. L. Wellsa, J. E. Dollarhidea, R. E. Mundell Jr.
Communications in Soil Science and Plant Analysis, Volume 31, Issue 15 & 16 September 2000 , pages 2707 - 2715


Phosphate foliar fertlization as a source of phosphite residues
L. Tosi, M. Malusà
ISHS Acta Horticulturae 594: International Symposium on Foliar Nutrition of Perennial Fruit Plants

Very good read may have to use my PK booster as well and the pure flowers sparyingly

even though this round did excellent with no other pk booster some plants did not react as well so maybe that is the reason....

thanks, do you reccomend not using scorpion juice if I were to use pure flowers foliar?

swordfish said:

thanks, do you reccomend not using scorpion juice if I were to use pure flowers foliar?

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too different products mean to do kind of the same thing... i would test it on one plant first but i do not think it would hurt it... however do use a pk booster with it

Interesting read. Thanks.

Thanks for the info.

these scientists only know what we farmers teach them. Never the other way around.

@ all,

I am "gojo", the author of the article Dave was kind enough to post for me. One thing I forgot to mention in my article is that phosphites will hinder and prevent AM fungi (and other endomycorrhzial fungi) from forming mycorrhzia (symbiotic infection) to host roots because phosphites are systemic fungicides. This is yet another reason to not use phosphites (ex. Pure Flowers) as a P source, phosphites should only be used as a fungicide...

swordfish said:

thanks, do you reccomend not using scorpion juice if I were to use pure flowers foliar?

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Scorpion juice is salicylic acid, it is a SAR (Systemic Acquired Resistance) inducer. SAR is when a plant goes into defense 'mode', and often the plant grows faster, is more stress resistant and yields better. However, and this is a BIG however, salicylic acid reduces glandular trichome density (over X leaf area) and development!

A good SAR inducer is methylated jasmoic acid (apply as foliar spray from 25-100 ppm), it not only induces SAR, but it also increases glandular trichome density and number! Plants naturally use methylated jasmoic acid to form tirchs, along with GA3 too.

grapeman said:

these scientists only know what we farmers teach them. Never the other way around.

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...I had to lol at that one bro, but not in a mean way You and I are [edit: were] friendly , but you know me as a different nic. I once told you why tensiometers are (most probably) the best way to quantify soil-water status, ex., for your grapes...

Hi, in the UK there is a nute co called Vitalink. They use phosphites instead of phosphates in there grow/bloom feeds. Are you guys saying that it shouldn't be used this way?

Whole thread on it. https://www.icmag.com/ic/showthread.php?t=171808&highlight=phosphite

evlme2 said:

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What? Information is information, if people choose to act like little children calling one another names it doesn't devalue the info...

Skyver said:

Hi, in the UK there is a nute co called Vitalink. They use phosphites instead of phosphates in there grow/bloom feeds. Are you guys saying that it shouldn't be used this way?

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This topic blew up in the other thread zenoonez posted, there was unfriendly posts between some members (including myself) in the last pages of that thread, that is why Evlme2 posted the cop emoticon.

I don't want this thread to turn into what happened in the last thread, so I will give you the CliffNotes on what phosphates can do. This will be my only response in this thread, and I will provide only the facts.

If Evlme2 feels he needs to lock this thread, it's fine by me :

--------------------------

Exactly, phosphites (Phi) are a very poor source of P, and they cannot be used as the primary source of P. If a plant is low on P, and Phi is provided, then the Phi is most often deleterious to the plant. Also, if a plant uptakes Phi, it hinders the uptake of the regular chem fert source of P: phosphates (Pi).

If a plant uptakes Phi, then the Phi stays as Phi in the plant tissue, and does not provide P because all known/studied plants do not have an enzyme that can oxidize Phi into Pi for P. Phi must be converted (oxidized by bacteria) into Pi before it is taken in the plant, to provide P to the plant.

The process of oxidization of Phi into Pi by bacteria, so the plant can use Pi for P, takes a while. It takes week(s) depending upon the amount/type of microbes present. Also, if there is Pi or "dissolved organic phosphorous" (DOP) available, the bacteria will first use the Pi and DOP as energy, before they convert Phi into Pi, allowing the plant get use the converted Pi as P...thus the process is even slower if Phi is co-applied with Pi.

If Phi is used as the only P source then the plant will become P deficient in a short time and will not be healthy.

Phi is a fungicide, not a direct source for P, because for Phi to provide P bacteria must first break it down into Pi (i.e. the normal source of P from chem ferts). Thus, a grower should just provide regular Pi fertilizer for P, not Phi, because Phi needs to be broken down into Pi before it can provide P. Using Phi for P is a very poor idea by VitaLink because Phi doesn't provide P directly, it must first be broken down into Pi, and that takes week(s).

Any company that is selling Phi as a direct P source, esp. if they claim it's better than Pi (normal phosphate ferts), is selling snake oil, because Phi is a very poor source of P. Any company selling Phi as a direct and superior P source are a bunch of idiots.

Along with all the references I posted above, here are two other good, and very current reviews:

1. "Phosphite (phosphorous acid): Fungicide, fertilizer or bio-stimulator?"
Hoang Thi Bich THAO, Takeo YAMAKAW
Soil Science & Plant Nutrition, Volume 55, Issue 2, pages 228–234, April 2009
http://onlinelibrary.wiley.com/doi/10.1111/j.1747-0765.2009.00365.x/abstract

Abstract

Phosphite (Phi), a reduced form of phosphate (Pi), is widely marketed as either a fungicide or fertilizer or sometimes as a biostimulant. This is confusing for both distributors and growers.

The present paper explores data from various studies to clarify that Phi does not [directly or efficiently; edit spurr] provide plant P nutrition and thus cannot complement or substitute Pi at any rate. In addition, Phi itself does not have any beneficial effect on the growth of healthy plants [except as a poor SAR inducer for some plants; edit spurr], regardless of whether it is applied alone or in combination with Pi at different ratios or different rates.

The effect of Phi on plants is not consistent, but is strongly dependent on the Pi status of the plants. In most cases, the deleterious effect of Phi is evident in Pi-starved, but not Pi-sufficient, plants. Plants fertilized with Pi allowing for approximately 80–90% of its maximum growth might still be at risk of the effect. This negative effect becomes more pronounced under more seriously Pi-deficient conditions.

Although a number of studies have shown positive crop responses to Phi, these responses are likely to be attributable to the suppression of plant diseases by Phi and/or to Pi formed from oxidation of Phi by microbes. In addition, indirectly providing P by Phi-to-Pi oxidation is not an effective means of supplying P to plants compared with Pi fertilizer.

An understanding of these issues will aid the right selection of fertilizer as well as minimize the harmful effects of Phi use on crops.

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2. "Understanding the Phosphonate Products"
Department of Crop and Soil Sciences - Cooperative Extension
Prepared by Peter Landschoot, Professor and Joshua Cook, Dept. of Crop and Soil Sciences, The Pennsylvania State University
http://www.scribd.com/doc/20206361/Understanding-the-Phosphonate-Products

Phosphonates were first investigated as fertilizers in Germany and the U.S. during the 1930s and 40s. At that time, agricultural officials were concerned that war activities would disrupt vital shipments of rock phosphate for fertilizer production, so alternative sources of fertilizer phosphorus were explored (6).

Results of studies conducted in both countries demonstrated that phosponates were not effective substitutes for phosphate fertilizer. USDA scientists found that yields of legumes and grasses treated with calcium phosphite were lower than phosphate-treated plants, and in most cases, lower than controls plants receiving no phosphorus. However, a second crop seeded into the same soils that were treated with calcium phosphite showed improved yields. The authors attributed the delayed phosphorus response to the conversion of phosphite to phosphate in the soil (9).Subsequent research revealed that phosphite could be converted to phosphate primarily by soil-borne bacteria, but that these bacteria would not use phosphite until most phosphate was depleted (1).

Based on the results of these studies, phosphonate fertilizer was viewed as an inefficient and costly means of supplying phosphorus to plants and scientists eventually lost interest in this compound as a phosphorus fertilizer.

Despite previous research findings, phosphonate compounds are marketed by some companies as a source of phosphorus and potassium fertilizer.

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The grass on the left got Pi as a P source, and the grass on the right got Phi as a P source:

zenoonez said:

What? Information is information, if people choose to act like little children calling one another names it doesn't devalue the info...

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No, but it WILL get the thread closed.

evlme2 said:

No, but it WILL get the thread closed.

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I have been here long enough to know that. I was just wondering why the cop made an appearance here. Lol. Too bad we can't just all get along. Lol.

I have had a few interactions with evlme2, and IMO he is one of the best mods I have ever come across at any forum. I think he didn't mean anything against you, or I, he was just letting people know to behave. I think he had the best intentions with the cop emoticon at heart, I think he is very fair.

If it were a few other mods, then I could see your point, but after my interactions with evlme2 I think he didn't mean anything rude or threatening by it, to you, or to me.

How old are you?

I neither started this or the other thread regarding phosphites. I never contended that it was either the phosphites or K were resulting in results that myself and others have seen using pure flowers.

The only fact I stated was that since using phosphites in the form of nutri-phite K (all foliar) in my vineyards (for almost 20 years), my P levels have consistently remained where I want to maintain them and I have been able to reduce the use of heavy phos acid applications to the soil. Major reductions. Saving money reductions. And I have validated these P levels with petiole analysis.

Some growers, either here or on other crops would find that of interest since high applications of phos acid in the soil have been shown to be detrimental to microbial life in the soil.

The reason I ask how old you are is obvious in your posts and your new sig.

I read the other thread and I think both sides have some pretty good arguments and I bet anybody who read that thread LEARNED some good shit about nutrients and soil. I have a special text file where I save really good info I read and I've taken several things from spurr's posts in the other phosphite thread and many of his other posts. His knowledge of chemical processes involving plants is far beyond mine and many others.

I think using somebody in a negative light in your sig is taking it a little too far. Keep it civil, boards are a good place for discussions but not arguments. I'm no mod but you oughta take the grapeman out of your sig, but I like you linking the thread so more people can read up on all of this.

In the end I think you are both right I think, spurr, that you are right and that the phosphites do not (at least in any convenient time frame) provide a good source of P. It's possible that some other process is going on in grapeman's fields involving possibly the phosphites, possibly involving any other thing in it, that is positively affecting his P levels. It sounds to me like in a large scale commercial operation such as grapeman's there are many variables and he is unable to run a full on 'scientific'-type blind experiment that might isolate the phosphites with his grapes. I think that until this goes to that point neither of you are really arguing about the same thing, and I hate to see people get upset over something silly like, "apples are tart", "NO! Oranges are orange!", and so on...