Your tree looks great; so don't stress. Whatever did that damage to a few leaves is not there now. BTW 12-4-8 is the perfect NPK ratio for Meyers; just be sure it has, or you add Mg, Ca, Iron, and Zinc. Your tree shows no evidence of any of those deficiencies.

Leaf curling alone is a physiological condition caused by stress; it's common in stressed plants, including young plants which don't have the root system to support all their foliage yet, or in times of unusually bright sunlight. If you get it by itself, look to see what may have stressed the plant recently; often it's nothing to worry about. The wilting, dead green leaves symptom resembles bacterial wilt, but that's pretty rare in your neck of the woods, and tends to take the whole plant down very rapidly. Stem borers can sometimes do it; look for little holes in the affected stems. Look for any damage to the stem, in fact. With the yellowing and necrosis -- it's hard to see in that small a photo, but it looks like the dark lesions are following the veins. That's diagnostic of a toxin of some kind -- no virus I know of does that in tomato, no bacterium or fungus is that specific, and no deficiency kills the veins before the interveinal spaces. I've seen a symptom almost identical to that in a case of alcohol poisoning (someone had a cocktail party in a library foyer and apparently the drinks weren't very good, as the potted plants looked pretty rough afterward). It was an unusual enough symptom that it became a teaching example. Toxins can come from outside or from the soil. Pyola is perfectly safe for tomatoes, and the heat wasn't excessive, but make sure the dilution was correct, as too high a concentration can burn leaves much like that. Spray damage can also cause wilted and dead green leaves. If you can sacrifice a plant that's badly affected, dig it up to look at the roots, see whether it has lots of crisp, white, fine roots, not dark or knobby ones. Shave away the skin at the soil line to look for discolorations in the woody stem underneath; cut open wilted green shoots to check for hollow centers from stem borers; and finally split open the main stem to see whether it's hollow or discolored inside. I don't expect much except maybe root symptoms, but you really never know. My personal guess is soil toxicity, especially given that the lower and terminal leaves are the worst affected by the yellowing and dying, and some things take a while to build up in the leaves enough to kill them. One important thing to note is that not all toxins are synthetic chemicals -- an excess of certain minerals or nutrients can poison a plant. pH affects root uptake of anything enormously, especially minerals, but it can have its own effect as well. You may need a soil test -- call your Agriculture Department, Cooperative Extension, or U of O to find an affordable lab. I don't see your symptoms in any of the common nutrient toxicity listings, though, which means it could be something chemical, and there is no general panel for that. Down here in California I'd send it to Sacramento's Plant Diagnostics lab or the extension pathologist at U. C. Davis, but I don't know what pathologists you have at your disposal. This is certainly not a cut-and-dried common disease problem, and even a specialist is going to need some lab work to figure it out, I suspect. I wish I had more answers for you, sorry. --Alison

There just isn't enough information in a picture of one leaf to have an idea of what's going on. A picture of the whole plant and close-ups of it (with several affacted leaves) would provide an idea of what patterns there are. Are you planting in soil or containers? What is your soil like? What are you feeding the plant, if anything? How's the moisture level? Is the yellowing starting at the bottom, or on one side, or all over? What area of the country are you in (zone 9 covers a lot of places)? How large are the holes, and are they clustered on one part of the plant? What do the spots look like: color, shape, dead or just discolored? The more descriptions you can give us of your situation, the better we can help you. --Alison

It is normal for citrus to drop older leaves, especially on established trees like this one. And it's always a good idea to fertilize regularly. But on the third leaf from the right, I think I see Whitefly larvae and their white stuff they leave around them. And I think the first two leaves may have a little bit of sooty mold, which would come from the Whitefly larvae droppings, a sweet sticky substance. It looks like a pretty mild case. On a tree that size they won't really damage it, it's more of a nuisance then. But if I were you I'd take the hose with a spray end and give it a good hard wash with water, especially on the under sides of the leaves. That will get rid of a large percent of them, then I'd do that every week for a while, say a month or so. That will help get rid of new ones as eggs left behind, hatch out. Overall though, johnmerr and pip are right, it's in pretty good shape, just need some food.