5

On some of my chili peppers (approx 1 month old, grown under artificial light), the leaves are rolling up / shriveling up, and little light-green raised dots are appearing on both sides of some leaves. The dots seem to be denser along the veins of the leaf, particularly on the underside.

What could be the cause of this, and what can be done to fix it?

Plant with rolled-up leaves, dots on leaves Different plant, more rolling-up, fewer dots Leaf underside

Michael Graf
  • 151
  • 1
  • 6
  • Some kind of insect infestation or oedema - be very useful to see a picture of the underside of the leaves if possible. Leaf rolling or leaf reversal often occurs when its too hot for the plants, or at least, too much uv light – Bamboo Mar 18 '18 at 15:21
  • Thanks! I've added a picture of the underside. It shows nicely how the dots / bumps / whatever follow the veins. – Michael Graf Mar 18 '18 at 15:55
  • What is happening to my chilli plant? How can I help it? https://gardening.stackexchange.com/q/4171/1894 – Graham Chiu Mar 18 '18 at 16:19
  • The top picture shows a powdery crystal on the leaf which looks like honey dew, and there seems to be a scale insect visible – Graham Chiu Mar 18 '18 at 16:21
  • Thanks a lot for the link, Graham. I saw that article earlier, but -- even though the "dots" look similar -- noticed a few differences: The leaves of the plant in the linked article didn't roll up like those on my plant; instead, they developed light/transparent spots, and later brown spots, which mine did not. That's why I decided to go ahead and post my question. If it's indeed honeydew, I should be able to wipe it off with a wet cloth, shouldn't I? – Michael Graf Mar 18 '18 at 16:56
  • Yes, or if it's dried as crystal brush it off – Graham Chiu Mar 18 '18 at 18:29
  • I think Bamboo's right about the edema. You might consider giving it some wood ash and a little extra ventilation. – Brōtsyorfuzthrāx May 18 '18 at 02:13

1 Answers1

1

There is what appears to be a small brown insect on the topside of one of the leaves in the first photo - can't really tell what it is.

Otherwise, the rolled leaf edges could be due to too much uv (you'll know because you know what type of grow lights you're using) but otherwise, edema might be the issue - that also can cause leaf rolling round the edges, as well as this blistered, bumpy look, see here https://www.gardeningknowhow.com/plant-problems/environmental/treating-edema-in-plants.htm

I can't tell from the final image whether the tiny bumps are insects, or whether it's more evidence of edema (or oedema, as I spell it!), but if you suspect an insect infestation, use neem oil spray to treat with, spraying both the top and underside of the leaves as well as the stem. Otherwise, for edema, some adjustment to your watering regime is necessary, as mentioned in the link above.

Bamboo
  • 131,823
  • 3
  • 72
  • 162