|Every 10 days or so, I find a white substance, looking very much like granulated sugar, on my hot pepper plants. I have about 10 pepper plants growing in pots under fluorescent lights in my house. I just shake the plants and the substance is gone for 10 days. Do you know what it could be? I thought it might be minerals from our hard water, but I don't water the leaves. Several of the plants were growing outside this summer and now are inside. Others were started in soil-less mix inside. All seem to be flourishing. The only bugs I've seen are a few small black flying insects, which look like gnats. I've got basil, parsley and oregano growing in another part of the room - and these don't seem to have the 'sugar' on them.|
|When plants take up a lot of water they respirate through lenticels on the surface of the leaves. Sometimes a residue is left behind. Since your plants are growing under lights, the lights may be evaporating the water at a fast enough pace that it leavesa dot of residue and that may be what you're seeing.
Aphids are small, oval-shaped insects about 1/8 inch long; they usually attack the newest, most tender parts of leaves and occur in clusters -- and they move. Whiteflies can look like whitespecks, but they'll fly away in a cloud if disturbed. So, if the white spots are not moving, they're probably not aphids or whiteflies. Spider mites moltings look like tiny white specks; to check for these pests, mist plants very lightly and lookfor any signs of webbing on the new growth. Plants with spider mite damage have a stippling or mottling of the leaves.