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Ctpumpkin@optonline.net

It is no secret that some commercial pumpkin growers are finding it cheaper to buy, ship & resell pumpkins from other states rather than deal with the expense of treating for Phytophthora (Phyto hereafter). PA has been hard hit I know.

Phytophthora is soil borne & infects it's hosts root system & renders it unuseable. The entire plant then wilts & can succumb very quickly.

Some open minded growers have used any of several Phyto fungicides regardless of the label constraints in an effort to control this dreaded disease. Banol, Subdue, Aliette/Signature, Prodigy/Signature, & a whole raft of others are known to perform. But all of these are very expensive. And to work well, the treatment must begin just before the start of symptoms & continue as a drench every 3 weeks until the threat has passed. We're talking 3 applications at costs of around $500 per acre. So a single AG in someones backyard that has grown to 1500 sq ft would cost about $17.00 each time that plant is treated. So $50 per plant is to be expected if all goes as planned. But first we'd have to fork over the mula-schmula for the bottle of stuff. Subdue is over $500 per gallon nowadays. Aliette is running about $20 per pound.

There are organic alternatives. Bacillus subtilis is found in such preperations as ProMax & Companion. But this isn't going to cut the mustartd in patches with a history or places where Phyto is just rearing it's ugly head for the first time.

continued

5/8/2003 8:41:41 AM

Ctpumpkin@optonline.net

Aliette is the cheaper of the good Phyto fungicides & it works very well. At $19/Lb it is applied at a rate of 8 oz per 1000. So about $10 per 1000 sq ft or $440 per acre each time. Pretty scarey for the commercial grower I'd say. The fungicide is going to cost more than he can take in profit in some cases.

All is not lost though.

Aliette is now off patent. And some suppliers are now bringing competitive products to market at much lower prices. How? By not registering them. And the federal government & Bayer Corporation are not happy about this at all. Now don't get me wrong here. Bayer & I are thick as theives. I won't recommend using anything in a manner that is inconsistant with it's labeling. That would be a violation of federal law.

Registration costs are incredible. Millions of dollars incredible.

But the active ingredient in this case can be marketted as a FERTILIZER! How you ask?

continued

5/8/2003 9:18:40 AM

Ctpumpkin@optonline.net

POTASSIUM PHOSPHITE. As PP is converted to Phosphoric acid, it causes the causal pathogen of Phyto to die. Very complex process that I don't have time to get into. And even though it's labeled as an 18% Potash (0-0-18) K supplement, all pumpkins can benefit from this cheapo source of K (that is converted to P). Especially if we get nearly 100% control/supression of Phyto by mistake. Did I say that?!?!

Selling this stuff as a fungicide is illegal. Now "Fosphite" has allready gotten EPA registration as an off patent Phyto fungicide. So it costs a good deal more than a fertilizer supplement. They're entitled. They had to pay for that number.

But unless we engage in commercial production, we could use the straight up fertilizer supplement to our advantage.

GREENFLO PHYTE 0-0-18 is registered in most states.

It is a fertilizer supplement marketted to relieve summer stress symtoms on turf & ornamnetals. But any crop would benefit from an occasional shot of supplemental potash.

At 6 oz per 1000 it costs about $2.81

$122.00 per acre isn't bad for fertilizer. Is it? And no reading between the lines. That would be illegal.

-Steve

5/8/2003 9:18:48 AM

Ga.

so would 0-0-60 have same effect as 0-0- 18?

5/8/2003 10:13:48 AM

Garden State Pumpkins

Yikes Jeff!!!between the lines! LOL

5/8/2003 10:33:48 AM

Ctpumpkin@optonline.net

No. 0-0-60 is just plain old fasioned Muriate of Potash. Also known as Potassium Chloride. Cheap & salty. Makes a good de-icing compound due to it's very high salt index. It's a totaly different thing all together.

Phosphonates & Potassium Phosphite are converted into phosphouric acid in a complex chemical reaction that kills the Phytophthora causal pathogen along the way. When it's labeled for control of Phyto & Pythium, it's a fungicide & has to be registered. And until just recently, the US Patent laws kept it that way. But now that the patent on Fosetyl Al (active ingredient in Aliette) has expired, potassium phosphite & other phosphonate compounds can be sold legally as supplemental fertilizers.

I have a whole boat load of documentation on this process. But it's too much to type here (and I can type too!). Let me see if I can find a few published references on the www somewhere & I'll link us to them in a later post.

For the record. These phosphonates & Phosphites are having a huge impact on out nations golf courses. With the current economic slump, the superintendents are faced with a shrinking budget for chemicals while rounds are still on the rise. To keep their jobs, they have to deliver the same or better turf quality as they did 5 years ago. But they have to do it on a smaller budget. How? With this stuff.
Many of the finer country clubs in this area now have Phosphite sprays built into their summer fertility program to take the heat off the chemical fungicide budgets.
The same fungicides used to battle pythium & phytophthora on golf courses contain the same active ingredients used in commercial agriculture. The trade names change to reflect new federal worker re-entry standards that are required on the ag versions, but the stuff is the same.

Steve

5/8/2003 2:19:06 PM

Ctpumpkin@optonline.net

Here is a story about some of the industry turmoil this has caused:

http://www.organiclabs.com/news.htm

Pretty funny if you think about it. - Steve

5/8/2003 2:28:33 PM

Ctpumpkin@optonline.net

Another link to one companies marketing concept of the new phosphorous acid compounds:

http://www.organiclabs.com/phytofos2.htm

5/8/2003 2:32:17 PM

Ctpumpkin@optonline.net

THE EFFECT OF THE FUNGICIDE PHOSPHITE ON CELL DIVISION
M.M. Fairbanks, G.E.St.J. Hardy and J.A. McComb
School of Biological Science and Biotechnology, Murdoch University, Perth, Australia

The fungicide phosphite is used to control Phythorthora cinnamomi Rands in Western Australia. Fungicides may have secondary non-target effects on plants either through an effect of the applied compound, or after its metabolism in planta. These effects range from poor germination and stunting of plants to genetic changes including chromosomal and gene mutation leading to inherited alterations. We have recorded a significant reduction in pollen fertility for native Australian and horticultural species after phosphite treatment. To determine whether the fungicide causes abnormalities of cell division, Vicia faba and Petunia hybrida were sprayed with phosphite to run-off, and mitosis in root tips observed. There was no effect on mitotic index but the proportion of mitotic cells with chromosome abnormalities was high for 7 days and was still evident up to 21 days after spraying. Phosphite also significantly increased the percent of cells with cytological abnormalities at all stages of the meiotic cycle of Tradescantia virginiana microspores for 7 days after spraying, and the effect lasted for 28 days.

5/8/2003 2:43:46 PM

Ctpumpkin@optonline.net

EFFECTS OF POTASSIUM PHOSPHONATE ON PHOSPHORUS METABOLISM IN PHYTOPHTHORA
J. Niere1, G. DeAngelis1, J. McDonell1, F. Stringer1, J.H. Grant1, B.R. Grant2
1Department of Applied Chemistry, RMIT, Melbourne 3000 Australia
2School of Biochemistry, University of Melbourne, Parkville 3052, Australia

Potassium phosphonate is an effective and selective inhibitor of many plant diseases caused by the fungal genus Phytophthora. The biochemistry of Phytophthora differs in many ways from that of the true fungi. In particular, unlike true fungi, Phytophthora contains little or no long-chain polyphosphate but an abundance of the short-chain, acid-extractable polymer (1). 31P NMR spectroscopy was used to examine changes in phosphorylated metabolites within living mycelium of the plant pathogen, Phytophthora palmivora over twenty-four hours. Mycelium raised in conventional, defined growth medium afforded spectra consisting of relatively narrow peaks, some of which were superimposed on broader resonances attributed to pyrophosphate and short-chain polyphosphates. Treatment of Phytophthora mycelium with potassium phosphonate over a period of days is known to induce formation of isohypophosphate and increase levels of a phosphate ester and of pyro- and tripolyphosphate1. The in vivo NMR spectra displayed increases in the phosphate ester and isohypophosphate signals within 6 hours of phosphonate addition. However, corresponding increases in the pyro- and polyphosphate regions were absent and the intensity of one of the polyphosphate signals decreased.

1. Niere, J. O., De Angelis, G. & Grant, B. R. (1994). The effect of phosphonate on acid-soluble phosphorus components in the genus Phytophthora. Microbiology 140, 1661-1670.

5/8/2003 2:44:49 PM

Chesterfield, MO

wow

5/8/2003 9:30:43 PM

Appalachian Mtns.

You the man

5/8/2003 10:07:42 PM

Usa

You really are interesting to read.
I have learned a lot reading your postings.
I would love to try the product.
But I wouldn't know where to even look for it.

5/8/2003 11:33:38 PM

Garden State Pumpkins

Yikes!...Hey g1t looks like cation exchange to me! So for us dummies in NJ Phytophthora doesn't like potassium phosphonate. Just checking to see if I got the gist of the post...Thanks Steve.

5/9/2003 6:44:25 AM

Ctpumpkin@optonline.net

Yikes is right. I just re-read what I wrote in the novel up above.

-TYPO- I said Phosphoric acid. That's wrong. The conversion creates "PHOSPHOROUS ACID" which is a highly soluble P that is part of the interference equation caused to the Phyto by the Potassium Phosphite.

Diane,

We sell GreenFlo Phyte 0-0-18 in 2.5 gallon jugs & 5 gallon cases. It's about $60/gallon. OK to send email.

I think we will see retail packaging od these types of things in the future.
Steve

5/9/2003 9:59:34 AM

Sparta, NC

Very interesting reading. I live in the nothwest mountains of North Carolina. Our christmas tree industry is also greatly affected by Phyto, but it is not too cost effective to apply these chemicals because of the acreage that would need to be treated.

5/9/2003 7:52:40 PM

Ctpumpkin@optonline.net

Sambo,
It may work very well on conifers. I don't know. The citrus industry is using it. Avocado growers are reporting good results too.
Pumpkins? Never seen a single published document. But folks have used Aliette before & had fine results.
This stuff is still too new to commit large acreage.
But when a grower is faced with no other financially acceptable alternative, this might save the day. Until such time as growers begin to experiment with it, this is all speculative. But given the outstanding results other plant health care managers are experiencing, it won't be long before pumpkin growers try this approach too.
The key to succesful implementation is proper timing & application technique. All the while keeping in mind that it's still recorded as a fertilizer supplement to keep the state & federal pesticide authorities out of it.

Keep in mind too that the price I eluded to is for one 2.5 gallon jug. Large quantity purchases are going to cost even less. So no solution to Phyto problems has ever come this close to being agronomically sane at the commercial level. I think it will be interesting to see how this works out in the long run.

Steve

5/9/2003 11:00:43 PM