Dendrobium yellow leaf pattern

[gabiborza]

Hi guys! I need some advice from the experts here. I have a couple of dendrobium keikies from july of last year. This year, back in february-march, the leaves developed some kind of yellow spots, within about a month or so. Since then the spots didn't develop further, didn't progress, didn't regress. The new pseudobulbs are ok, no spots on them. Only the old ones, from last year. Any ideea what this could be?
Here are some pictures. There are some sunburn spots, which they got because I moved them outside a couple of months ago, under full sun.

[Paul Mc]

I'm not on expert on symptoms of virus' or diseases, so perhaps someone else with a more trained eye can assist further than I.

In my humble opinion, since the leaves on the new growth are fine, I'm tempted to say that the older leaves may have experienced some sort of environmental stress (over/under watering, too much light, etc...). However, when my Den's start doing this they continue and eventually fall off. It's more the fact that they are getting old and shedding their leaves while creating new growth. If this is the case, just let them run their natural course and do not remove the leafless canes as they are still nourishing the plant. Only remove the canes once they have dried up and browned. It's possible to even get bloom spikes off of leafless canes as well.

Again, I'm no expert on diseases or viruses, so if it truly is a symptom of something else, I would fall to the thoughts of someone else on this one.

[gabiborza]

Thanks Paul! The older canes were potted in fresh bark wich I collected some time ago, and I would say they were underwatered, as the bark didn't stay moist enough. Those were my first keikies ever, so I didn't know what I was dealing with. As I mentioned, the leaves are like this for a good six months or so, and the new canes look good, no signs of yellowing.

[Paul Mc]

The fact that it has not progressed is a good sign.

Often times, orchids produce keiki's when they are stressed. That being said, they also produce keiki's when they are mature enough to do so and have the energy stores available. The fact that you have keiki's may be a testiment to both.

My own dendrobiums don't necessarily always produce keiki's. Most of them do so when they are stressed, although I do have one that produces them every year and I have to give them all away to a good home, lol...

[gabiborza]

Sorry if I wasn't understood Paul. I got those last year, as keikies, from a friend. His dendro nobile had a lot of them, and shared a few. They didn't make keikies, but basal new growths.