Clowesia 'Grace Dunn' rotting bulb

[Roksana Jędrzejewska]

Hello, I have a problem with Clowesia 'Grace Dunn'. Today, when taking the plant from the greenhouse for weekly watering, I noticed that the bulb is rotten, and just a week ago there were no symptoms that could indicate rotting.
I don't know what to do, cut out the bulb completely, or maybe try to remove the rotten tissue? How to "dress" a wound? I hope that someone has had a similar problem and can give me some advice.

IMG_20231007_173325.jpg - Google Drive
IMG_20231007_173330.jpg - Google Drive
IMG_20231007_173342.jpg - Google Drive
IMG_20231007_173353.jpg - Google Drive

[estación seca]

Welcome to the Orchid Board!

Tell us your growing conditions - temperatures, relative humidity, light. How are you watering and how are you fertilizing?

Unless your relative humidity is extremely high I don't think watering once a week is enough for this kind of orchid. I think it's possible that pseudobulb died from lack of water.

I would leave it alone. If you try to cut it off you will damage the roots on the newest growth. I don't think it's rotting and I don't think there is infection to spread to other growths.

[Roksana Jędrzejewska]

Originally Posted by estación seca

Welcome to the Orchid Board!

Tell us your growing conditions - temperatures, relative humidity, light. How are you watering and how are you fertilizing?

Unless your relative humidity is extremely high I don't think watering once a week is enough for this kind of orchid. I think it's possible that pseudobulb died from lack of water.

I would leave it alone. If you try to cut it off you will damage the roots on the newest growth. I don't think it's rotting and I don't think there is infection to spread to other growths.

Thank you for the quick reply!

The plant is grows in an apartment inside a foil greenhouse together with others (mainly Dendrobium).

The temperature in the current period (autumn) ranges from 18-26°C.

Air humidity oscillates between 60-90% (when it drops to about 60%, I sprinkle the plants).

They are now watered once a week, and twice in the summer.

I fertilize them with 1/2 of the recommended dose of fertilizer each time I water them.

I illuminate them with LED lamps for plant.

The only problem I have is with air circulation inside, I finally have to install fans...

Is it possible that such a change is necrosis due to lack of water? There is actually no odor, but the affected tissue itself is slightly soft.

[Roberta]

I wouldn't worry about the pseubobulb that might be rotting... these tend to absorb tissue from old growths to support the new (especially if it was kept too dry). Your plant is still in the growing phase, so should be watered heavily. Another 6-8 weeks, you should start reducing water to encourage dormancy (but you need to get those new growths plumped up first) In winter, these lose their leaves, and at that time should get no water. If it hasn't gone dormant by January, stop watering anyway. Blooming will occur on dead-looking leafless pseudobulbs in around February... don't be tempted to water.. Wait until the new growth is well established (10 cm roots) about 2 months after that for watering to resume.