Looks like salt burn... where do you live? Do you by chance have a water softener and use that water to water your tree.

You also have evidence of Magnesium deficiency... see the green Christmas tree shape in your leaf, with the outside being more yellow? Mag. deficiency can be solved easily by the application of Epsom Salt; all my garden lemons get it at the same time I put it on my roses. I live in Guatemala, so I cannot find Epsom Salt; I buy commercial Magnesium Sulfate... same thing, just a bit more concentrated than ES.

I am in California. I will get some Epsom Salt soon. That Azomite should have some in it. But since this is in a pot it may be flushed out already. What tells you that there is some Salt burn? Is it the brown tips?

Exactly, the brown tip is the first sign of salt burn; could be too much fertilizer, common salt, lack of good drainage... other things. Oddly enough, the most common cause of salt burn is people watering their plants with water from the water softener, which replaces mineral salts (hard water) with sodium chloride (common table salt)

If you do have salt burn, and the tree is in a pot, you should flush the pot to rid the soil of excess salts on a periodic basis...

Actually, I'm thinking this is manganese deficiency, and not magnesium. Here in California for us, it's manganese, then to a much lesser extent, iron. As our weather warms up, this will dissipate. Use a good citrus fertilizer that has micronutrients (Gro Power Citrus & Avocado Food, which is a properly balanced fertilizer with correct micronutrients plus humic acid). And, you can also use either a foliar micronutrient spray, such as Grow More Citrus Growers Blend or a granular product such as FST. (I would steer away from Ironite - too much iron for our area, if you're in S. Calif.) If it is salt burn, that will go away if the tree is in the ground. If it's in a larger pot, then flushing the pot with water as mandarin1 has mentioned is the remedy. And, usually, most folks who have water softeners only have that attached to their inside water, and not their outside water here in California for a myriad of reasons - cost to "soften" outdoor water, plus the added and unwanted salts in your yard. It is a rare thing to have your softener attached to all your water supply.

Patty S.

No I use just the plain old hose to water my plants and trees. On hand I got Citrus Tone as well as Azomite which has tons of minerals in it. Think I should add more?