What it is
A fungus that grows on the leaves like a white powder, looking like flour. It covers the leaf, blocks its light and weakens it. Its spores fly and spread fast through the whole grow.
How to tell
Small white, powdery spots, first on a few leaves, that grow until they cover them. If you run a finger over it, the powder comes off. Affected leaves end up yellow and dry. On the buds it ruins them: they can't be smoked or sold.
What favors it
High humidity, still air, many leaves piled up and big temperature swings between day and night.
How to fight it
Sulfur or potassium bicarbonate, sprayed, and removing the most affected leaves. Lower the humidity and move the air. Sulfur is not used in late flowering (it leaves a taste in the buds) nor together with oils (it burns the leaves).
How to prevent it
Keep humidity below 65 % (the dehumidifier helps) and check often with the lens.
▲ Pros
- Caught early it heals almost without damage
▼ Cons
- Untreated it can kill the plant, and in a batch it spreads to the next batches
🎮 Practice it in UnderGrow
Cured with sulfur (treat), which also prevents it for a week (7 real h). It's favored by over 65 % humidity and cool air (under 21 °C). At first you can only see it with the lens.
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