Causes of soft rot and bud rot and how to prevent and treat them
Symptoms of soft rot: In the early stages of soft rot, a black line runs from the rotting area into the other bulbs, and there is a yellow halo around the black line. Take a close look - is there a black dot at the upper corner of the wound? This is the cross-section of that black line. Once you cut it open and the wound shows this color, throw it away, don't...
When the temperature is >30°C, be sure to pay attention to ventilation and shading, otherwise soft rot easily occurs. Remember this!
Symptoms of soft rot:
In the early stages of soft rot, a black line runs from the rotting area into the other bulbs, and there is a yellow halo around the black line.
Take a close look - is there a black dot at the upper corner of the wound?
This is the cross-section of that black line. Once you cut it open and the wound shows this color, throw it away and don't waste water - there is no specific cure at all.
If this clump of orchids has many seedlings, keep cutting further back until the wound is white.
If you cut back to a white cut surface, let it dry for a while, and it no longer turns yellow afterward, this plant can still be saved. Probably not much will be left though.
Bud rot:
Bud rot is sometimes caused by physical damage or water damage to the growing core.
In bud rot, the boundary between the yellow spots and the green leaf areas on the bud is very clear.
Orchids with bud rot are easy to save, and there is no black line extending inward; as long as the wound is treated properly, they will still sprout.
Spring orchids (Cymbidium goeringii) with bud rot are the easiest to save, and after being saved they do not relapse - orchid growers with many years of experience should have felt this.
This is what some orchid growers mean when they say "soft rot" can be cured.
Soft rot is different - you can carefully compare the two.
In seedlings with soft rot, the yellow halo radiates outward from the lesion.