Flower spikes that turn black and die on vandas, cattleyas and dendrobiums - Orchid Board

LILOBODO · #1 (**permalink**) 05-30-2008, 01:10 PM

I have several vandas, cattleyas, and denbrobiums that have been happily coexisting on our lanai for several years. Recently, they all develop what appear to be normal flower spikes, but all either turn black and dry up, or the flower is deformed. Sounds like virus disease to me. What do you think?

khill · #2 (**permalink**) 05-30-2008, 01:17 PM

The first thing I would check for is pests. Thrips can do exactly what you are describing.

LILOBODO · #3 (**permalink**) 05-31-2008, 12:30 PM

Thanks for offering a ray of hope. Can you give me some suggestions as to what I should be looking for when I check for thrips?

fredr · #4 (**permalink**) 06-13-2008, 04:19 PM

I didn't see any response to the question about thrips. How does one find them?

I have the same problem with some new growth. Others on the same orchid are fine. What gives?

See picture.

I have this problem with several plants. I have 'banrot' on order as I think it might be a fungus of some kind.

Fred

Dorothy · #5 (**permalink**) 06-13-2008, 04:30 PM

Try this link - it has some photos in it - Insect and Arthropod Pest Identi
and this one - Diagnosing culture problems - Pests

fredr · #6 (**permalink**) 06-13-2008, 04:43 PM

Wow! 40 pages and not a single reference to a black spike tip and no pics.

The second link has colored pics but nothing close to my problem. Have you ever had such blackened tips?

Fred

Dorothy · #7 (**permalink**) 06-13-2008, 05:00 PM

No, Fred I have not

isurus79 · #8 (**permalink**) 06-13-2008, 06:26 PM

The only time Ive ever seen this type of thing happen was with a Cattleya skinneri. The rot on top was a symptom of total rot down at the root level. I almost lost the whole plant. This happened during our rainy season a few years back and the plant is still recovering, though nicely I might add. LILOBODO & Fredr, I would definitely pull your plants out and check for some rot either on the roots, p-bulbs or rhizomes. If thats not the problem, then I dunno!

Des · #9 (**permalink**) 06-13-2008, 07:10 PM

Only time that I have seen flowers flowers go black ,was one very cold winter we had here with some frost that got to the plants
It could also be botrytis a fungal infection which develops during an early morning temperature drop
Could it be something that the folks next door are spraying to get rid of weeds ( had that once )
Anyhow hope you find the problem .

Rothie · #10 (**permalink**) 06-14-2008, 12:39 PM

Dorothy-
Thanks,once again,for more helpful links!