Help identifying issue with my lemon tree

[Sam707]

I have a dwarf 4 year old lemon tree in the ground and it looks diseased.  Does anyone know what is causing the issue and the remedy?  I tossed the last two years harvest because the fruit is unsightly and unappetizing.  I would hate to remove the tree if it can be salvaged.  Thank you.

[Citradia]

If you live where it isn’t going to freeze in winter, I would fertilize with a balanced slow release fertilizer since you have yellowing leaves. I’m guessing it’s not HLB, but needs nutrients. Do you fertilize during the growing season?

[Millet]

I am going along with Citradia.  A 4 year old, and older, citrus tree should be fertilized 3 times equally spaced out over the growing year. The tree looks under fed in several elements such as nitrogen and probably potassium, with one standing out - magnesium.  The problem now is that we are going into the winter months, a time of year when citrus are not fertilized.  However, in the case of magnesium, winter would not deter you from apply a magnesium supplement.  The common supplement normally used is Epsom Salts (Magnesium Sulfate).  Epsom Salts can be applied either through the roots, or as a foliar spray.  As a foliar spray, dissolve 1 tablespoon Magnesium sulfate in a gallon of WARM water PLUS 1 tsp. of a good surfactant and spray the upper and lower surfaces of the leaves.  You might have to apply several applications several weeks apart. It can also be applied to the soil.  Or you could apply one application to the soil covering the area of the trees drip line, then water it into the root zone, and several weeks later a foliar spray.  If your area does not get a hard  winter freeze you might also apply one fertilizer application of either a granular fertilizer such as a 6-6-6 or 8-8-8 or even a slow release fertilizer.  NOTE: leaves already showing magnesium deficient symptoms (a green delta shaped leaf center with yellow out on the leaf edges) do not always correct themselves.  However, when the deficiency is corrected the new growth should become fully green.

[Sam707]

I am guilty of not fertilizing it but will heed your advice to do so to correct the issue.  I have a dwarf naval in the same yard with a similar issue, but the leaves are still a nice green color.  Is the treatment the same?  Thanks!

[Millet]

Not as bad, but you should fertilize it 3 times a growing season.  Nutrition is especially needed by young trees.  A good fertilizer programs develops the foundation branches of the tree.

[laidbackdood]

as below.

[laidbackdood]

IMHO i like to go organic at the last month of winter....something that smells bad !!! hahaha....it then has a month to break down with the winter weather/rain ready for when the plant needs it at the beginning of spring......Thats the most important feed of the season.....from the summer on.....i use a chemical slow release with soil microbes and trace elements.......manures in summer are not such a great idea.
I put chopped up banana skins on my figs and tomatos because they have no nitrogen but good levels of phopshorous and potassium.
but i feed everything once a month ....little and often...rather than big feeds which can burn....6 inch circle around the trunk which i call the circle of life.......never put any food there because there are no feeder roots there anyway.