Colleagues, I need help with a diagnosis!
I decided to grow a tobacco plant on my balcony as an experiment. The seedlings were grown under LED lights in a thermal box where I previously fermented tobacco (stable humidity and temperature). I selected the strongest plant and transplanted it into a 1.5 L pot.
While it was still in the small pot, in the box, dark spots appeared on one lower leaf. They turned yellow and dried out. I removed the leaf and, after 2–3 days, transplanted the plant into a 20 L pot (store-bought soil + perlite + vermiculite). It stands about one meter from a window, south side, with almost no direct sunlight and no drafts.
Watering is moderate — about 150 ml, only at the root. Even right after transplanting I did not overwater. In total, I watered it about three times. The soil is moderately moist, not waterlogged; the edges look a bit dry.
But the spots keep appearing. Here’s what I’ve already tried:
The last two days have been cloudy and rainy, but the balcony is dry — no dew. Nearby on the windowsill, “on the front line,” there are three small backup plants, and they are completely clean.
The bottles in the large pot are empty — just taking up volume because I didn’t have enough soil. I’ll remove them and add fresh soil once it settles.
What could this be? A virus? A fungus that doesn’t respond to treatment? Or some kind of stress? The white spots are the result of treatment with a fungicide and Bordeaux mixture (1,5%).
Should I discard the sick plant and switch to a backup, or keep observing?
Any thoughts would be appreciated!
I decided to grow a tobacco plant on my balcony as an experiment. The seedlings were grown under LED lights in a thermal box where I previously fermented tobacco (stable humidity and temperature). I selected the strongest plant and transplanted it into a 1.5 L pot.
While it was still in the small pot, in the box, dark spots appeared on one lower leaf. They turned yellow and dried out. I removed the leaf and, after 2–3 days, transplanted the plant into a 20 L pot (store-bought soil + perlite + vermiculite). It stands about one meter from a window, south side, with almost no direct sunlight and no drafts.
Watering is moderate — about 150 ml, only at the root. Even right after transplanting I did not overwater. In total, I watered it about three times. The soil is moderately moist, not waterlogged; the edges look a bit dry.
But the spots keep appearing. Here’s what I’ve already tried:
- Fundazol (market advice: “fungus”) → overnight it spread across the whole leaf, so I removed it (you can see it in the photo, separated)
- Bordeaux mixture (ChatGPT suggested “bacterial leaf spot”) → but after a day, today, a new spot appeared on a lower leaf again
The last two days have been cloudy and rainy, but the balcony is dry — no dew. Nearby on the windowsill, “on the front line,” there are three small backup plants, and they are completely clean.
The bottles in the large pot are empty — just taking up volume because I didn’t have enough soil. I’ll remove them and add fresh soil once it settles.
What could this be? A virus? A fungus that doesn’t respond to treatment? Or some kind of stress? The white spots are the result of treatment with a fungicide and Bordeaux mixture (1,5%).Should I discard the sick plant and switch to a backup, or keep observing?
Any thoughts would be appreciated!
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