Copper fungicides - safe for phrags?

[xiphius]

My Phrag. hirtzii seems to be developing some small black spots on some of the leaves. They don't appear to be spreading particularly fast or be particularly virulent, but I would like to spray the plant to prevent them from spreading and possibly prophylactically spray the neighboring plants as well (Phrag. pearcei). They are small and dry, so I assume some form of fungal spotting:

I have used copper fungicides - Phyton 27 (copper sulfate pentahydrate) and/or Bonide (copper octanoate) - on my paphs many times in the past without any adverse reactions. Generally, I really like copper since it is very effective and very broad spectrum. I am comparatively very new to phrags though and have never had to spray them. I know they have a reputation for being more sensitive. Are copper fungicides phrag safe (obviously when used as directed ), or will they burn?

If not, any suggestions on an alternative would be appreciated. Thanks!

 

[Happypaphy7]

While waiting for others to answer, I'm not into phrags, but a few I have tried seem to easily have leaf issues, which are huge turn-offs for me in growing plants. I want them all nice and clean looking.

Any warnings I have read about against copper based fungicide is not to use on Dendrobiums. I don't know why as to the interactions and such.
I'm curious.

By the way, have you heard of Dragon's Blood?
It is a dark red sap from a tree called Croton lechleri.
It has a proven microbicidal property.
You might want to search it on this website as it has been discussed quite a bit and many people report good results including myself.

 

[xiphius]

Yeah, I tried once with phrags in the distant past and failed pretty quickly. But I only every had one and it was a very small seedling. I tried treating it like a paph and, at the time, I wasn't yet using RO, so... all reasons why it probably failed . I have grown/learned a lot since then so I figured it was high time I tried again. They are doing much much better this time.

While I don't mind a few small leaf spots, I definitely don't want them spreading! Good to know about dragon's blood! I will do some looking around on here. I have heard of it, although I am not familiar with Croton lechleri. I grow Dracaena draco, which also produces a red antimicrobial sap called dragon's blood (although I am not sure if the potency differs). Do people spray their plants with dragon's blood? I was under the impression that it was mainly used as a dressing for cut surfaces? I am a huge fan of cinnamon for that purpose (very cheap, effective, and easily found).

 

[Happypaphy7]

No, you definitely don't want to spray it around ever!
It dries almost immediately and stains everything, leaf, skin, paint, clothes...
Plus, it's not that cheap like cinnamon power, speaking of which, I don't see any good use of it other than as drying power and good scent.
Nothing like Dragon's Blood.
Wear a vynl glove, put a tiny drop on a finger tip and rub it thin on the affected area, and most anything will stop spreading.
You don't need to use a lot as long as the disease spots/marks are fully covered.
So, a small bottle lasts for a long time.

Yes, there are a few other plant sap with the same name, but you have to make sure you get Croton lechleri.
I read that it has been used by the native people of South America for a long time as a natural antibacterial bandaid on small cuts and such, so to speak.

 

[xiphius]

Gotcha. Yeah, I didn't think people sprayed it, but I was curious because it almost sounded like that was what you were suggesting I do :rollhappy:. I will definitely look into it for sealing cuts though. Doesn't look like a small bottle is terribly expensive. So it will probably give it a go at some point.

 

[abax]

You might also try Cleary's 3336 which is a systemic
fungicide if that leaf damage is, in fact, a fungus.

 

[Ozpaph]

Is it insect damage with secondary fungal infection? Kill the insects.
There must be cheaper ways to use copper sulphate....

 

[Ray]

Despite the opinion expressed above, cinnamon (actually the cinnamaldehyde it contains) is actually a pretty good topical fungicide with some bactericidal action as well. In my opinion, the only use for the powder is for open wounds, but extracts made with alcohol or water are also quite effective, and may be used more broadly. If you want to go more powerful, consider cinnamon leaf oil (also to be used in a solution), which contains eugenol, which is a very effective topical.

 

[xiphius]

Is it insect damage with secondary fungal infection? Kill the insects

The thought had occurred to me, but I checked. No insects. I think it is just fungal spotting. I did up the airflow though. I had pretty decent airflow, but it maybe wasn't quite enough. Moved it closer to the fan.

Despite the opinion expressed above, cinnamon (actually the cinnamaldehyde it contains) is actually a pretty good topical fungicide

Ray, you don't have to sell me on cinnamon, I have been using the powder for years and agree that it is very effective. For the cinnamon leaf oil, what concentration do you typically use? Also, how often do you reapply?

 

[Ray]

I used to resell the stuff from cinnamonvogue.com, as it is the best quality I've seen, and they recommend 1% in water. I have always used 1 teaspoon in a 16 ounce bottle of rubbing alcohol (1:96, a shade over 1%), and kept a spray head in it, so it was handy.

I have used it on plants, to cure fungal infections on me, like athlete's foot, and it also makes a great "pee spray" when housebreaking a puppy.

 

[xiphius]

For those interested, I swatched a leaf with the copper octanoate fungicide and didn't see any reaction after a few days. So I covered the pot with plastic to keep excess copper off the media and then sprayed the whole plant. It has been well over a week now and no ill effects!