Undersides of leaves look fine? If so, I'd go with lack of Magnesium. Try giving about 1/2 tsp per gallon next time you fertilize.

Let's see what others may have to say.

Kevin

This post was edited by woohooman on Fri, May 2, 14 at 0:45

Odd pattern. Try what Kevin mentioned - Epsom Salt. You should see a difference in just a few days. If the yellowing continues, it could be too much moisture in the root-zone, lack of nitrogen, et cetera.

What exactly is your fertilizer?

Josh

Same opinions as Kevin.

Sometimes Magnesium is already in the soil but not available to the plant; I have read an article that suggested foliar spraying Epsom Salt ( 1 TB spoon per gallon of luke warm water).
It is also a QUICKer dose than applying ES into soil.

Check the Ph first.

Woohooman, if you're referring to pests damaging the leaves, I haven't seen any.

There's Osmocote Plus in the mix and they get Foliage Pro at about 1/4 strength.

pH is about 6.5.

I'm going to try an Epsom salt spray and see if that does anything.

Increase the Foliage Pro to half-strength, or more.

Josh

weirdflowers: No. I was referring possibly to edema. Seems to be more common lately. google a pic of pepper edema and you'll see what it looks like.

I'm sticking with the Mg theory. I'd do as Josh suggested. The Foliage Pro has Mg in it. Last year, a couple of mine looked similar---Josh suggested upping the ferts(Miracle Gro = no Mg) and epsoms(Mg)...voila!

Kevin

Ahh yeah, I've seen edema on some of my peppers in the past, but it never seemed to be associated with any kind of nutrient issue before. It looks like a couple of these plants do have it.

Does that change anyone's advice?

This post was edited by weirdflowers on Sat, May 3, 14 at 16:38

Edema usually means overwatering. Not always, but usually. So, along with the above advice, let the soil dry out between waterings.

Soil almost bone dry, water thoroughly. Let dry out again, water thoroughly. And so on.

Kevin

Do a search on growing in coir, advice from peat/soil growers is going to kill your plants :)

Letting coir go bone dry is going to skyrocket the substrate pH, the only time you do a wet/dry cycle is while establishing roots.