Fungal Warnings: #1-Garden Safe Fungicide and #2-fusarium in peat

[Cynthia, Prescott, AZ]

I think the following needs to be brought to our visitors attention:

#1 - A new product has come on the market in the US (Arizona?) that has 'Fungicide' on the label. DO NOT be misled by the name. This is a ready to use neem oil only product and please don't use it on orchids thinking you are protecting them from fungal diseases. There are a couple of us that are pretty sure that neem oil CAUSES fungal problems. This is not to put down the above product. I am sure it does a good job with mildew on roses, and I just came home with 5 bottles from Walmart, as it is an inexpensive ready to use neem oil product. But those of you who have followed my problems with fungal diseases know I have done a lot of research on/with systemic fungicides, and this is NOT one to use as a fungicide. I personally think that neem oil stresses orchids making them vulnerable to fungal attack, some more than others, like the very thin leaved and terete leaved orchids. Even Cattleyas appear to get a mottled look on their leaves after its use, and keeping them out of heat and light for a few days does not help. I have been using a systemic fungicide on those that are being sprayed with neem, and so far I have not seen any additional mottling. See my comments below on fusarium fungus for systemic chemicals to use..

#2 - I have read recently that a number of unopened bags of peat moss, I assume from different sources, were tested for fusarium fungus, and all were found to contain the fungus. Imagine, if you will, the curse words that emanated from my lips. My husband complains that I am not very lady like when I get like this. I am quite sure that the severe problem I have been having in my GH with what I believe to be fusarium wilt derives from this source. The fungus can live in the mix with out the presence of a host plant, just waiting for a moment when the plant is under stress. I think I finally have the matter under control with the use of Thiophanate methyl (Cleary's 3336, OHP6672 [my choice because it is sort of liquid, not a powder]), and a whole lot of other names. This is the only systemic that lists the particular fusarium fungi that are common to orchids. Phyton 27 does not list any fusarium species to its credit. My last batch of mix (1/3 peat) got a teaspoon of truban added to a cu ft. Truban is not systemic, but I had it and it does control a lot of root rot diseases, and I am currently drenching my re-pots with the Thiophanate, and recently drenched the pots of my entire collection with it. I will be ordering Banrot to put into my mix, which contains both the thiophanate and truban. Steaming the peat would work too, but is not practical. If you use peat, you might look for pre-steamed peat, if they make it. In the mean time, I am delighted to report that I found on the web a small quantity jar of Thiophanate methyl for those of you that may want to have this in the wings for suspected problems. I also use this as my spray for all wounds as I repot or trim plants. Fertilome is a common brand at Nurseries around here, so it may be available locally. I will be looking. Note that the label contains the word 'Halt'. This is a brand name, and should not be confused with the actual chemical, as there are many chemicals with the name Halt on them. Check the chemical name on the label, second site below, to make sure you get the right stuff. I have had no problems with extensive use of this chemical, with the possible exception of the shortening of flower spikes, a temporary thing.

http://www.stokestropicals.com/detail.aspx?ID=367

http://www.fertilome.com/Labels/Fert...lt%20Label.pdf

UPDATE: I see that Oak Hill Gardens has Bonomyl (Thiophanate methyl [Clearry's3336 equiv.]) in 2 oz containers as well as Phyton 27 in 2 oz bottles.

[palito]

thanks for that Cynthia.

I have used that Garden Safe product on one plant (severe spider mite infestation) I have been spraying it along with a cocktail of another pesticide and fungicide. I'll be careful not to apply it alone then.

re: fusarium. It was my understanding that fusarium spores are basically everywhere. How do you detect a fusarium infection since it is in the roots?

[janet_a]

is it this stuff? (which has been around for a while)

http://www.gardensafe.com/ProductCat...de/Fungicide3/

i use it once or twice a year on the orchids and amaryllii, prophylactically, and on the AV's for powdery mildew, and on the gynura for aphids. (not very effective.)

will have to ponder this.

[Tony]

Cynthia

I am a real novice with Orchids, but have you tried Messenger mixed with Serenade? Messenger is special Harpin Protein that makes the plant think they are sick and kicks in their defense mechanism's. Seranade is an organic fungicide. It works great on tomato plants to prevent and stop blight and I used it on Cattleya that was starting to develop some fungus and it seems to have stopped it. This my second year using messenger and the first time I mixed it with Seranade. Tony

[kmarch]

I used neem loi fairly regularly (when it was warranted) to control outbreaks of soft bodied insects like mealy bugs. I used it on Catts, Coel and a few other thick-leaved genera without any adverse results. I had heard it should not be used on thin-leafed orchids like Paphs so i have not done so. It is possible that Neem oil used undercertain growing conditions could be detrimental, as was Cynthia's experience, but this was not the case in my growing conditions.

[Cynthia, Prescott, AZ]

Polito: the fugal infection that I have had in my plants is systemic thru the entire plant, and is not limited to the roots. In fact, it is the wilting of the leaves that is the first sign of the problem. In my reading, fusarium certainly has been described as infecting the entire plant. I will work tonight on getting some pictures loaded up on pbase of the wilted leaves.

Kevin: I think the mottling I have seen on Catt leaves very well may be a local fungal type that may be dependent on local conditions for its presence. Here is an example of the mottling.
http://www.pbase.com/schnitz/image/57062947

[Gladys47]

I have a dend with that same mottling. Has had it all summer.New growth looks fine and is spiking. I thought it was due to too much sun and did not give it another thought as I slightly burned some of my plants in spring when the sun decided to move in just one day! I do use the stuff in the green bottle and also Bayer rose spray. What to do? Just when you think you know it all you find that in reality, you know nothing! Gladys

[Cynthia, Prescott, AZ]

To all, I have updated the last of my posts above with pictures of the probable fusarium problem and some more mottling pics.

Gladys, I have been growing for 45+ years, and look at what I am learning, finally! Keep an eye open at garden shops/nurseries, as some carry a systemic fungicide that you can use as a chaser when you spray with neem, and use neem only when truly needed. I use it solely for mites that are immune to other insecticides and only on plants that time has shown that mites like. I keep a pink label in the pots of such plants, and when I discover more mites any where in the GH, I will spray all the pink label plants prophylactically to stop any spread.

[Aniko]

Cynthia - Thanks for the warning and information.
In my neighborhood, this time, there is no available Fertilome or Banrot, or other similar product, so I ordered from the Stokes Tropicals.

I can not observe any signs of disease on my plants, but the medium (peat/perlite) of a freshly re-potted Phal, after few days has been covered by fine, floss like "something". Fortunately, this was a singular event, but tells me that it's time to use some fungicide before the situation turns worst.

[sandra]

Originally Posted by Cynthia, Prescott, AZ

#2 - I have read recently that a number of unopened bags of peat moss, I assume from different sources, were tested for fusarium fungus, and all were found to contain the fungus.

With this said, I'm wondering now if I should return the bag of Canadian peat moss I just bought to use in my mix for some of my phals. I think I will...

[Aniko]

I'm afraid, we can expect fungus infection from any mix or medium. I've found mycelium in my Schultz Orchid mix, too.

[Tobi]

Unfortunately due to the way these are packaged, there is not much you can
due when you purchase them. They sit in warehouses that are sometimes
damp and since they closed and never exposed to light, they are prime for
mold and fungal growth. What I do is spread any medium that I buy (including
bark) on a flat bed container and expose it to sunlight and drier conditions
before I use them. You can also use a fungal spray of your choice if there
are any concerns of mold.

[prisana]

Cynthia, that was good info..thank you. I haven't had that much luck with neem and I'm only using it as last resort on certain part of certain plant. I will keep an eye out for those stuff you mentioned.

Talk about unlady-like reactions... I once opened a bag of newly purchased bark mix only to discover it was covered in mold. I didn't keep the receipt so I put the mix in the aluminum tray and poured boiling water over it and let it soak a while and then used it . I was just glad no one was around to hear me and my potty mouth at work.

Same thing happened to my own batch of mix I made myself and stored in a large air tight tupperware.. so now before I store it , I'd add some fungicide to the bark mix and it hasn't happened again...yet.

[missann]

Oh my God, I almost used the 3 in one garden safe fungicide on my new phals today!!!
I am pretty sure I have used it on my orchids before, but I will no longer use it on them.

Maybe you could drench the peat moss and stick it in the microwave. Microwaves kill everything.

[JLu]

Palito, fusarium is not everywhere...until it gets there.... and then it stays in soil basically forever. In pots it's easier because you can discard (carefully) the potting medium and get new, unaffected material.

Peat moss is the product of decaying vegetation material in a bog. The anaerobic conditions halt the rotting and peat is what you get. This bog is a cocktail of crap that can harbor most anything. I wouldn't use it in somebody else's greenhouse. There is no control over what it contains. Bog to bag to you. By the way you won't have to guess if you have fusarium...It blocks the water passages in the plant and kills it.

"Microwaves kill everything."

I wouldn't bet on that. If you put in dry it might not even absorb microwaves. If it does it's likely to catch on fire. Ever read about peat bog fires? If you wet it, it will only get to 212 F (100 C) which is unlikely hot enough to help much.

Coir is much safer to use...just rinse it really good to remove any sodium chloride.

[kid a]

Hey I bet that garden safe is the reason I lost one of my plants a few years ago! Out of the two I treated one died within a week. Completely gone! The other is my "comeback phal" still recovering from rot issues that I used garden safe on. I have a feeling it wouldn't have been so bad had I used a better product or even cinnamon dishsoap water and repotted it.

[aacor]

I have posted something earlier but it disappeared. Anyway, to resume fusarium is sensitive to certain lactobacilii in acid soils provided the infection si not too advanced; fusarium is also greatly promoted by the use of inorganic nitrogen sources (for references try google searches - I shouldn't post links)
"Antifungal activities of two Lactobacillus plantarum strains against Fusarium moulds in vitro and in malting of barley
The competitive ability ofA. radiobacter when tested in twelve Central American soils was found to be related to pH in acid and neutral environments but was correlated with texture, organic-matter content and total nitrogen in soils of intermediate pH. In all soils where inhibition occurred, the competitive effect was overcome by additions of inorganic nitrogen.
There is also this: "Suppression of Fusarium solani f. sp. phaseoli on Bean by Aluminum in Acid Soils"

this is a quote from a penn state univ article - "Conversely, there are at least two turfgrass diseases (take-all patch and Fusarium patch) that are suppressed in acid soils." this led me to believe that Fusarium might be sensitive to acid soils. Perhaps someone with more experiece could shed some light

[fred]

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