Welcome to OrchidTalk Orchid Forums
The Friendliest Orchid Community on the Internet!
OrchidTalk - "Bringing People Together to Grow Orchids Better!"
Let us help you grow your Orchids better; Join our community today.
YES! I want to register an account for free right now!
Register or Login now to remove this advertisement.
This oncidium was “forgotten” in a shady area under a tree, where it gets watered regularly. I looked at it yesterday and saw all this powdery mildewy stuff all over the roots and basket. We’ve had a lot of rain here over the last week or so that probably hasn’t helped. Other than being a little waterlogged, the roots, leaves and the plant in general is (or seems to be) healthy. How can I get rid of the white stuff?
Posted via Mobile Device
Posted via Mobile Device
Posted via Mobile Device
You basically have two alternatives - chemical or biologic treatments.
For the "chemical" way, you have two options; disinfectants or fungicides. Physan 20 is a great disinfectant, but Biosafe Systems Disease Control has less phytotoxicity. Cleary's 3336WP (generic: thiomyl) is likely the most effective fungicide. Copper-based treatments like Phyton 27 may work, but can be damaging to some plants.
For biological controls, Concentric Ag (formerly Inocucor) Garden Solution is the most broad-spectrum, curing and preventing diseases while boosting the plant's health in general, with other biological brands (EM-1, Quantum Orchid) being much narrower-scope treatments.