Fusarium and bacterial outbreak, physan, daconil, thiomyl, or copper based compund?

[Cdmcmonigle]

Yesterday I found a spot of rot hidden under a dry sheath on my Marfitch Howards Dream. I cut out the rot and when I cut into the rhizome I found that it had fusarium. I soaked the plant in physan 20 for 30 minutes and let it dry overy night. Tonight I potted the now rootless orchid in 60/40 leca and coco coir then did a soil drench with a combination of daconil and thiomyl. I later went to my grow room and found my Bnfd. Gilded Tower "mystic maze" and zgyo Australia to have have yellow leaves. The zygo was yellow with brown spots suggestive of bacterial brown rot. This happened in less than 24 hours so I can only assume it is bacterial with how fast it set in. These two orchids have been in a 9 site aquaponic system for the last two months. I immidiately removed them from the system and cleaned them up. The banfieldera had soft pseudo bulbs so I ended up tossing it but kept one leaf with a very small bulb on it. I removed the affected tissue from the zygo roots, bulbs, and parts of two leaves. They are currently sitting in the daconil/thiomyl solution. I am wondering what the best compound to spray the other plants with. I have physan 20, daconil, thiomyl, copper fungicide, bonides fungicide III ans neem oil. From what I have read most sites are recommending the copper fungicide since it works on bacteria as well. I am going to syphon the tank and was thinking about running the daconil and thiomyl solution in it over nignt. Does anyone have any thoughts on what would be best/better?

[estación seca]

For work surfaces, bleach. 10% solution of bleach you buy at the store.

Not all fungi are killed by all fungicides. You need to do some reading about what kills fusarium. I can't recall right now.

[Sharon's Sheepdogs]

Why do you believe the orchid is infected with Fusarium. Did you find a red ring in the tissue of the orchid? The only treatment I'm aware of for Fusarium is a product identified as 'Medallion.' Unfortunately, it is a very expensive product. Usually, by the time the red ring has developed, the orchid can't be saved. You can try cutting (sterilizing the blade after each cut) back to what appears to be healthy growth & pour some peroxide on it for several days in a row where you made the cut but the plant is probably already infected. Fusarium is an insidious disease. I will go back through some of the information I have on orchid diseases to see if I have any other information that might help.

As to the yellowing leaves on the other orchids, you need to identify the exact rot they are infected with to determine what treatment should be used. When I'm trying to identify a disease, I first go to the following two sites:

[url=http://www.phelpsfarm.com] Go to Orchid Related Links

Click on related links & then click on 'Orchid Pests & Disease' which will open an excellent article with photos to help you identify the disease & the recommended treatments.

Most of the info in that article comes from 'The St. Augustine Orchid Society.' You can go to their site for additional information regarding orchid pests & diseases at:

Orchid Pests, Orchid Diseases

I'll see what else I can find for you regarding Fusarium.

[Fernando]

Optimize the ventilation to prevent further rot.

[Cdmcmonigle]

I did find the pink ring on my marfitch. I cut out the infected tissue and treated it and am still continuing to treat it I'm quarantine. Thiomyl and daconil both claim to kill fusarium. As to the plants I believe it's a bacterial outbreak with how fast it occurred. I reference St. Augustine's site frequently, also. The site advises to use copper for a wide range of ailments. My biggest concern is prevention of the spread to my other plants. I am very diligent in my hygiene practices and provide very good ventilation to my grow room.

---------- Post added at 01:53 PM ---------- Previous post was at 01:51 PM ----------

Unfortunately, I didn't want to chance that so I ended up throwing out my zygo Australia since it seemed to the source of infection.

[Sharon's Sheepdogs]

I meant to get back to you regarding the orchid you found infected with Fusarium but have not been able to until now. There is a good website with information regarding problems affecting orchids at:

Hark-Orchideen - Competence in Orchids

Hark Orchideen is a commercial grower of orchids. You can go to their home page using the above link, then, on the left side of the page click on 'Navigation' & on the next page, click on 'Information on Crop Protection.'

On the page that comes up next, click on Fusarium where four topics will be listed across the top. Click on each topic to review the information provided. Under the topic 'Control' you will find a list of fungicides which have not been found to be effective enough against Fusarium. The fungicides listed are Carbendazim (Daconil), Thiophanat-Methyl (Cleary's 3336) & Prochloraz (?).

There are two chemicals which can help if the Fusarium is located at the base of the leaves. You can try spraying with Cyprodinil plus Fludioxonil (Switch) or just Fludioxonil (Medallion). Medallion is listed as a contact fungicide for the control of Fusarium. These are the fungicides that give you the best chance of stopping the spread of this fungus. Unfortunately, both of these chemicals are very expensive.

When I first started growing orchids, I unknowingly purchased a couple of orchids which I later found to be infected with Fusarium. The weird thing was the front half of the plant was blooming while the back end was infected. It can take up to a year before the infection kills the orchid. The problem though is the fungal spores are continuing to multiply and can spread to your other plants. I did a lot of research on Fusarium trying to save these two orchids but I was unable to.

I am not suggesting that you not try to save your orchid using Daconil & Cleary's 3336. However, if you are unable to get your infected orchid to root, I would dispose of the plant, the growing medium & the container. In the meantime, keep it away from your other orchids so they don't end up infected as well. Good luck!