| What you are seeing is very common in oncidium alliance plants.
I have this often with my orchids. The tips of leaves turn burn and entire leaves fall off. It is the result of heat and stress (or just age) but not burn. Sunburn on an oncidium will show up in the middle of a leaf not the tips usually where the leaf bends.
With our heat here in Florida every leaf on my oncidiums can look like this in August. If they look really bad I cure it with a pair of scissors and cut them off. Once new growth, has started I tend to ignore the old growth. Overly stressed plants can lose every leaf. I always judge the heath of a plant by the new growth not the old leaves.
Newly arrived plants will often lose leaves. The stress of shipping and the change of environment add to the problem. I notice a lot of roots outside the pot. This is common with oncidiums grown in greenhouses. They grow very fast. In the greenhouse they got watered probably every day and the roots did well as bare root. The change to your watering will kill back some of these (it is not a problem and can not be helped). I have the same issue with new plants especially if I mounted them and totally changed their method of growth.
After the flowers are finished you will see a lot of new growth. The new growth will be adapted to your growing conditions.
__________________
jerry  |