Answer: It's difficult to make a positive ID of problems. There are many insects and diseases that attack these plants. For example, the white dots you see could be whiteflies, which are minute sucking insects with powdery white wings that resemble tiny white moths. Or mealybugs, which have a cottony coating. You might try spraying a product containing neem oil, an organic spray which can help control both insects and diseases.
Sorry I can't be more specific.
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