Although your tree does not look fabulous, it also does not look all that bad either.  It is definitely showing a fertilizer deficiency, especially nitrogen.  When a tree it greatly deficient in nitrogen the leaves will be totally yellow with no variation of color, or yellow/orange veins with some green out on the far sides.  When the deficiency is less severe, as what your tree is showing,  Less severe shows up on older leaves with newer leaves still retaining some green. Your tree is currently showing a medium nitrogen severity.  At temperatures above 95-F growth stops in citrus trees. This is the time of year nearing the time to stop fertilizing.  I would suggest you first foliar spray the foliage with a nitrogen solution such as low biuret urea, or a fertilizer with a higher nitrogen content.  You might also apply a light fertilizer to the roots.  Do what you want, but for this tree I would not apply a organic fertilizer due to the trees immediate needs.

One last comment.  Chicken poop is extremely high in soluble salts, unless the poop has been composted. 

SoCal2warm,  you are certainly correct. However, the mistake stated in your post is not a mistake on the citrus's part, but rather is a mistake on the human beings part.

LBurford if your container plants are small, and if you don't mind taking the time, you could use your fingers to squash  the insects inside the leaves.  If the leaves have started to show the insects tunnels, simply squeeze the leaf at the very end of the tunnel to kill it.

SeaWalnut, the label is not referring to an insecticide, but the caution is because the fruit is washed in a fungicide bath.  Eating the fruit, or using its juice will not harm you in the least.  In my opinion you are being way over cautious. Actually just about all citrus varieties are washed in a fungicide bath, and have a wax coating applied to them, at least in the USA.  By simply washing the fruit in warm water should take care of the situation. However, do what you wish.

Macrophylla, should be OK in 9B.  Could have troubles with rare freak hard cold spells, but this could of course happen anywhere.

Buying seed off E-Bay is a dangerous gamble that they will ever germinate.

https://www.youtube.com/watch?v=JAAe8TnP3fQ&feature=youtu.be

Day tripper, does your P. Lime only bloom during the summer months?

In a follow up to Brian's post. I had a large in ground Bearss Lime tree.  It produced more limes then I could ever begin to use.  It only set one large crop per year, it did not bear fruit throughout the year.  I eventually got rid of the tree to replace it with a Valentine Pummelo due to the amount of space I have available to grown citrus.. Plus I don't use limes very much.

Common scale starts as an egg from its mother, usually on the leaves or branches of a plant. The egg then develops into two immature stages called Instars. The first instar stage are known as crawlers.  Crawlers move around the plant and in approximately one day's time settles down permanently on a particular spot of the host plant for the rest of their lives.  Then starts the second immature stage called the 2nd instar stage witch matures into the adult.  The adult causes all the damage to the plant by sucking out the juices of the plant. During periods of high temperatures scale can reproduce quickly.

Bomand, do you know the actual cultivar name of your poncirus seedlings?  I can see that they are not Flying Dragon.  they have a very healthy look to them.

Very interesting and hopeful.  As always time will tell.