Cymbidium fungus or virus - Orchid Board

jmateosky · #1 01-21-2009, 05:21 PM

I attached some fotos maybe ther eis an expert that might be able to Identify is this a fungus, or Virus or? These are cymbidium hybrids. about 3 years old. it is actual in our dry season, and we are watering the plants. These are grown in coconut husks and hair/fiber.

Hope you can help me,

Thanks,

Jim Mateosky

phearamedusa · #2 01-21-2009, 11:59 PM

Is this plant grown in a greenhouse? Is it possible that some really cold water dripped on it. To me, it looks like damage caused by freezing water, at least similar to damage on one of my Phal's in past.

jmateosky · #3 01-22-2009, 08:43 AM

Yes it is in a greenhouse, but I really think is a fungus or bacteria. Interesteing not I have a bunch grown in dirt and horse manure and they are all fine, just the ones grown with coconut. One of these might be damage to the leave but other are clearly an ifection. I had some cats with phythium or phytophthora it reminds me of that. but my low temps in the middle of the coldest night might get to 11C for an hour or so.

Intruder · #4 01-22-2009, 10:22 AM

What did you recomment as treatments for such diseases?
Is a treatment with mancozeb a good solution?

jmateosky · #5 01-22-2009, 10:33 AM

Yeah mancocep treated the catleya, now I use it regularly.

Unfortuantly I can not say for sure if that cured the cymbidiums, As I moved them to a sunnier dryier spot and dried them for a while. The last time I had this problem was last september when there was virtually no sun just clouds and rain. So I attributed this problem to the lack of light and excess water.

I am going to start a regular mancocep (sp) treatment now, It would just be nice to know what the problem is....

Thanks,

Jim

Gin · #6 01-22-2009, 10:44 AM

[QUOTE= Interesteing not I have a bunch grown in dirt and horse manure and they are all fine, just the ones grown with coconut. [/QUOTE]

Is it the coconut chips ? If so might be a build up of fertiliser salts , just a thought since the others in the horse and dirt are not showing the same problem .

jmateosky · #7 01-22-2009, 11:50 AM

the salts and over fert usually effect the tips, add we just repotted them in fresh coc 6 months ago.

This is in the middle of the leaves.

Des · #8 01-22-2009, 03:12 PM

Some of that looks like wind damage too me ,which i often get on the new growths here in Port Elizabeth . Also if you are growing under cover and condensation drips onto the leaves at night when the temps are low, then you will get some fungus problems . In cool weather,below 15 degrees C, I spray my plants with a contact fungicide every two weeks .Be sure to add a wetting agent to the spray as this will give you better protection. If you can also spray your whole greenhouse down every now and then, as this decreases the chances of fungal infections. I use a fogger for this , chat to your local garden shop they should be able to help

Intruder · #9 01-23-2009, 12:11 PM

Quote:

Originally Posted by Des

Some of that looks like wind damage too me ,which i often get on the new growths here in Port Elizabeth . Also if you are growing under cover and condensation drips onto the leaves at night when the temps are low, then you will get some fungus problems . In cool weather,below 15 degrees C, I spray my plants with a contact fungicide every two weeks .Be sure to add a wetting agent to the spray as this will give you better protection. If you can also spray your whole greenhouse down every now and then, as this decreases the chances of fungal infections. I use a fogger for this , chat to your local garden shop they should be able to help

Which contact fungicide do you use? I am interested.

Des · #10 01-23-2009, 01:37 PM

I mostly use Captab or Dithane. I also disinfect the feed water with Sporekill or hydrogen peroxide, this helps to reduce the pathogen count in the plants environment