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!
Follow up on Fusarium
Hybrid Mode
