Which is better fungicide: copper or sulfur?

[silken]

Originally Posted by Brooke

Don't some Dendrobiums have a negative reaction to copper based products?

Brooke

That's what I have heard. I was also told some Dens don't like imidacloprid which is the systemic pesticide used for scale.

[Orchid Whisperer]

If using copper based products, follow instructions closely. Copper can be phytotoxic if used too much.

[Ray]

Originally Posted by quiltergal

Physan 20 has no fungicidal properties. It is a bacteriacide/disinfectant.

Not true, Terri. Physan 20 is a bactericide, fungicide, algaecide and virucide. Specifically, it is a topical treatment, not a systemic one.

[PaphioAdict]

We get brown rot or brown spot on our paph's and Catt's and it is so depressing too loose so many in this weather. This year our greenhouse is not working so I am repotting like crazy hoping too curtail the high amounts of dampness you get with old orchid bark. I already threw away two paph's and cut off a Cattleya leaf due too this terrible disease.

Sending sister to Home Hardware too buy Bordo Copper Spray.

The weather is lovely however it's not the greatest for our greenhouse this year.

---------- Post added at 10:36 PM ---------- Previous post was at 10:32 PM ----------

Originally Posted by Orchid Whisperer

If using copper based products, follow instructions closely. Copper can be phytotoxic if used too much.

I am wondering how often is too often? Anyone want too share their experience using this with their orchids?

[Roberta]

Some orchid genera are sensitive to copper preparations such as Phyton 27, others are fine with it. I don't remember which ones are harmed by copper, so I mostly don't use it. Brown leaf tips on Cymbidiums probably not fungal... Salt buildup from fertilizer and/or hard water will cause the brown tips. It's important to flush the pots at least every 3rd or 4th watering, and let the water run through the pots. Some Cyms have more of an issue with salt build-up than others. But fungicide isn't going cure that one...

---------- Post added at 08:45 PM ---------- Previous post was at 08:44 PM ----------

Originally Posted by silken

That's what I have heard. I was also told some Dens don't like imidacloprid which is the systemic pesticide used for scale.

Never heard that about imidacloprid... have never had a Dendrobium problem with it.

[Leafmite]

Originally Posted by snakecharma

I would think that the copper base would be more suitable for root issues that the sulphur, but afaik both are fine.

I use a milk base spray for fungus prevention on leaves, it's what we use on our roses for the dreaded black spot. You guys know that one?

When I first started gardening, all of the old-timers recommended spraying milk on the leaves of plants to prevent fungus. I use this for my tropical plants when they are outside for the summer (I stop once I bring them indoors) and have never had a problem, no matter what the weather.

[dounoharm]

need a fungicide fast?? buy some rooting hormone...most of them have a bit of fungicide in it....it is a quick cheap fix....