How the rot happened (I think):
It all began with a repot.
More than a week ago, I repotted the B. nodosa I bought early November. The nodosa was in bloom but I spotted bugs in the substrate and, with the visible roots not in the best of shapes, I thought I'd take her out and have a closer look.
She was potted in, mostly, bark chips. There was moss involved (of which I shall elaborate upon later). I removed the as much organic media as I could then repotted her into a mix of leca and pumice (both soaked beforehand) in semihydro setup.
Then I made the mistake of upending a plastic bag over her to increase ambient humidity (and eliminating airflow). The plastic bag did little to increase humidity during the days, which were hot and measured around 30C/86F in temperature and 49% in humidity. The nights were much cooler at around 22C/72F and 68%.
A few days later, I noticed white fuzz (mold) growing on the canes and the exposed roots. All the growing root tips were dead or dying. I immediately removed the bag.
A day later, I discovered a brownish soft spot (pictures attached) at the edge of an old leaf that's in contact with wet pumice. The pumice was moved away, but the soft spot continued growing. I cut off the infected leaf two days after the soft spot was first discovered.
Yesterday, I found another infection (pictures attached). This time it's on the newest growth (which was slowly growing in length and roots before repot) and had, seemingly, spread upward from the cane. This soft spot spreads much faster than the previous one.
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I've tried comparing my nodosa's infected area with pictures on the St. Augustine Orchid Society website. I
think the rot is, and was, either brown rot or black rot.
I have no experience on rot and my amateur diagnosis includes both bacterial and fungal infection. So I'd very much appreciate a more experienced opinion on this.
What's the disease my nodosa's infected with? How should I treat it? Since the newest soft spot spread up from the canes, does it mean the rhizome's infected? Do I need to cut up the rhizome? What can I do to help my nodosa recover?
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More on the repotting:
The bark was in okay condition (as in not mushy or rotten). But the roots had adhered to the bark chips. I had to gently prise the chips off roots, accidentally tearing off a few roots in the process
.
Overall condition of the roots wasn't so good. The roots ranged from dry to desiccated despite the moist condition of the bark. As I unravel the outer roots, I discovered that the roots of some older pseudobulbs were around 2 inches in length, had signs of being previously rotted, and were wrapped around
soggy moss.
I don't know if those roots in moss were still viable, so I didn't cut them off. Aside from the roots I accidentally torn off, the only roots removed were the ones which velamen were falling off.
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Regarding attachments:
First two photos -- Front and back photos of infection on newest growth
today
Next three photos -- Front and back photos of infection on newest growth
yesterday
Next five photos -- Front and back photos of infection on the leaf that was cut off.
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I really
really like this orchid and very much want to keep her alive. So if you've got any suggestion/advice/personal anecdote, feel free to throw them at me. I need as much information as I can get!
And thanks for bearing through my lengthy, slightly panicked rambling!
Need help with Brassavola nodosa rot
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