NOID Den Blackening and yellowing leaves (new and old) - Orchid Board

Sandrilene · #1 02-24-2010, 04:13 PM

This is a continuation from my post from yesterday I didn't mean to leave the last title so vague I was having issues posting pictures and forgot to type the whole thing it on like my 5th try.

It's not just old leaves the ones that are all black and yellow. It looks the worst on a new part of the plant the one leaf that was pretty black I posted yesterday fell off and now the top one looks the same. I tried cutting the first black part off it before i went to bed last night and it still is taking the leaf. I have no idea what is wrong with it or what to do. I took more pictures today as suggested by white but couldn`t figure out how to attach them without a url to my post so I'm starting a new one. Sorry the root picture is blurry my camera refused to focus for it. Please help I don;t want to lose this plant.

Sandrilene · #2 02-24-2010, 04:52 PM

The flowers look like my avatar since it's a picture of this plant.

King_of_orchid_growing:) · #3 02-25-2010, 02:18 PM

Very interesting hybrid.

I believe it might be a Den that is a cross between a Den from the section Phalaenanthe (Den phalaenopsis type) and from the section Spatulata (Antelope Dens).

Fortunately, they're both "evergreens", so you don't have to worry about this guy having a dormancy period.

What are your cultural parameters?

Light?
Temperature ranges? Day/night. Seasonal.
How often are you watering?
Humidity?
Air circulation?

Sandrilene · #4 02-26-2010, 01:09 AM

Light? Not direct but pretty bright all day long
Temperature ranges?
Day/night. day i keep it around 70 night 65-70
How often are you watering? I make sure it gets completely dry in between waterings so about once a week give or take.
Humidity I don't know the number but it isn't dry and it isn`t overly humid
Air circulation is fairly good we use two fans in the room. It seems to be slowing down now that its lost like 5 leaves but it only have like 4 left so i'd kinda like to keep em if its possible. :S

WhiteRabbit · #5 02-26-2010, 03:43 AM

Have you repotted it recently?

King_of_orchid_growing:) · #6 02-26-2010, 06:20 AM

Were the fans blowing directly at the plant?

Humidity meters are not expensive. I highly recommend getting one. I think that this parameter is crucial to know in the orchid growing hobby.

I'm a little iffy about the temperatures you posted.

On one hand they aren't cold, which is good because they are intermediate to warm growing (60 F - 95 F). But on the other hand, there's not much of a temperature difference between night and day. At least a 10 degree F difference between night and day, on a consistent level, would probably do it some good. The temperatures shouldn't be consistently the same throughout the course of the day. Even in the tropics there's a significant temperature difference between night and day.

Are you misting this plant by chance?

Do the roots have green tips?

orchidsamore · #7 02-26-2010, 07:30 AM

Your photos 3 and 4 show sun burn. It should not get any worst than it is currently. The brown will never go away the chlorophyll is dead in this area. It does not spread nor will this small amount harm the plant.

Since it burnt again move it to an area where the heat from the sun will not build up on the leaf. It is the heat not the sun that burns a plant.

photo 5 is a lower leaf and they die from a lot of natural causes. Any leaf on a Dendrobium over 2 years old is doing very well.

Lower leaves on Dens will fall off if grown too cool or too dry over the winter.

Always consider the health of your plant by the condition of your new growth. Your new growth is fine except for the burn which you can prevent from getting worst. It is not necessary to cut off burn marks it does not spread.

Sandrilene · #8 02-26-2010, 04:28 PM

More leaves are falling off and changing to yellow with black areas on them. it is no longer in a room where it is getting light from the sun it hasn`t been for a few days now and more leaves are turning yellow and brown and falling off. no the fans are not pointed at the plants one is a ceiling fan and one is a big floor fan. the roots are white.

King_of_orchid_growing:) · #9 02-26-2010, 11:17 PM

1. Are they being misted?

If you are, I suggest not misting them anymore. It's not necessary to do it.

And...

2. It would be of great help and importance if the humidity was being measured with a meter, and if there was an actual measurement of it.

Your senses will fool you. I'll bet you'll be surprised by what the actual measured humidity is compared to what your body perceives the humidity to be.

This is important to know because it will determine how much you can allow the plant to dry out or determine how much you should water your plant.

The same can be said about temperature. Unless you have readings from a thermometer, I have the same thing to say about measured temperature versus perceived temperature.

I'm not making this up. I believe there are laboratory studies done on this phenomenon.

Then there's...

3. Is the pot sitting in water?

King_of_orchid_growing:) · #10 02-27-2010, 12:00 AM

This is not sunburn.

This is an entirely different problem.

If you're saying that air circulation is not an issue, then...

It appears to either be a temperature or moisture related problem.

Bacterial and fungal infections are usually secondary problems caused by the initial problem.