I'm not sure what it is, but I had the same thing happen to one of my Twilight plants... I tried to turn one of the two affected leaves to see the bottom and the leaf just fell off. The plant itself seems healthy otherwise. The other nearby seedlings do not have the same spots.

Are you using indoor lights?

I did a little research and it looks similar to a contact burn from fertilizer or a household chemical. Do the spots appear darker on the underside? I could be wrong but it's something to consider. Good luck!

Nope, same color on both sides.
Bruce

Hmmm... Are the areas dry and "crunchy"? Are they slightly transparent? Oh and how quickly did this appear/how long has it been present?

It just started a couple days ago. The affected areas are pretty much normal feeling. They are not transparent. On the Black Pearl, the areas are not dry and crunchy, but the affected areas look more like they are dead areas.
Bruce

Do they sort of feel paper thin and leathery, almost like a super super thin sueade? If so, I had the same thing last year with a couple of plants and they turned out just fine. I think mine came from a combo of the lights being too close/too bright and letting the plants get past the point of just starting to droop before I watered them. I had the full on droopy leaves when I watered them each time. all my seedlings last year wound up getting really dried out and burned up down to bare stalk, but they perked back up after a while and turned out just fine...

I also suspect heat burn.
Were they on the blaster side of the fluorescent ? That end gets pretty warm. And if the leaves are too close can get heat burn.

Same thing happened to me Bruce on just 1 plant. I think Seysonn may be right. It was only on one plant that was closest to the end of the tube.

Kevin

This post was edited by woohooman on Wed, Mar 5, 14 at 15:58

Sorry Bruce, I'm not sure what your problem is but given the issue is showing up on lower leaves of the Black Pearl, I'm questioning light burn.

I'm not familiar with Alaska Fish Emulsion. What does it include? Aside from NPK, does it include micro nutes?

Bill

No, the plants are not near the Ballasts. In fact the Black Pearl is only affected on the lower leaves. Thanks for the suggestions though. It doesn't seem to be getting any worse or spreading so I am done worry about it for now.

I have come to believe that Alaskan Fish Fertilizer is a nice way of saying Alaskan Fish Dung. Anyway, the NPK on it is heavy nitrogen at 5-1-1. The link below has all the specifics on it. I have seen it recommended quite often on this and other gardening forums....but it does stink. It says on the container that it is deoderized with Wintergreen oil. I just wonder how they got those mints up the fishes butt.

Here is a link that might be useful: Alaskan Fish Crap

This post was edited by esox07 on Wed, Mar 5, 14 at 19:10

How did you feed those plants with that fish thing ? Is it possible that it got onto the leaves ? Although it does not seem to be very strong , but it is some kind of unfinished soution that will go thru some chemical changes and decomposition. Correct me if I am wrong, it is not supposed to be used in a soilless medium.

It can be used on container plants as well as gardens, shrubs, trees, etc...
However, it is entirely possible that I got some on the leaves. I usually bottom water the plants but also pour some on the top of the soil to ensure there are no dry pockets, especially near the surface. So, yah that could be it. I will try to be more carefull in the future and might not use the stuff again until they are outside. It stinks, I think I already said that. It literally is fish crap I am pretty sure. My plants seem to like it so far....my wife, not so much.
Bruce

Forgive me if this seems like a stupid question, but if you suspect having gotten some of the fish emulsion on the leaves, have you tried washing it off? A spray bottle will do. I ask because I know it leaves a light brown/beige stain on foliage if it's a little on the concentrated side. It comes right off with water. That's probably not the case with the black one, but the Twilight leaf looks just like something I once did..

I'm only suggesting that because it freaked me out on another plant once until I realized that (just like you mention) the leaves did not seem dry or dead to the touch.

This post was edited by SproutingLexi on Wed, Mar 5, 14 at 21:48

True, true. Even a very dilute fertilizer solution, left on the leaves, will become a strong solution as the water evaporates, and can result in leaf burn. Always rinse it off.

Alex

Bruce, I had the same thing happen to me this year on a few plants. They were sitting over a radiant heater. I assumed it just cooked them as only about 4 or 5 of them (the ones on the edges) look like that. I figured combination sun and burning. And, since they are extremely healthy and have since put on a ton of leaves, I'm not concerned. Yours looks exactly like mine. I hadn't used any fertilizer when mine happened so I know it couldn't be that (but then I've never had a leaf burn from fertilizer, even when I make it strong- and I'm lazy, I always water from the top pouring it over the plants).
Pam

Hmmm. thanks Pam. They dont seem to be getting worse. I am growing in the basement which is in the 60's and there is no external heat other than my 4' floro shop lights. The only other thing I can think of is that I found one of my shop lights had 4100K bulbs where the other one has 6500K. I thought they were both 6500K. I think the two affected plants were under the 4100K light at the time. However, it is just those two plants so far.
I have 6500K bulbs in both now.
Bruce