"stake with fertilizer next to tree"

That doesn't help much. Absorbing roots are mostly at the dripline.

And cut your expenses by avoiding further purcahses of stakes.

Thank you, Jean0001a
Being a very small tree, dripline would be pretty close to trunk actually. I guess major question is there is any possibility to undetify if tree don't have enough fertilizer or if it root system is damaged.

Qwerty, if you can post some photos, that would be helpful. I agree with Jean, fertilizer stakes are pretty much worthless. You're better off using a good citrus fertilizer every 2 to 3 months along the drip line (even if that's close in to the trunk for now since your tree is young.) You can also use a good micronutrient foliar spray (Grow More Citrus Growers Blend). Also, I would suggest you check to see how moist your soil is about 2 to 6" inches down. Do you know what kind of soil you have? You didn't mention how often you're watering, and for how long. You need to check to see if the roots are waterlogged, or if they are too dry. If you upload your photos to Photobucket, then copy the .html code (there are 4 options, select the .html code) right into your message, your photos will show up right in your message.

Patty S.

Thank you very nuch, Patty S.,
I am complete novice with growing anything, lets alone citrus. I would be not able to tell about soil or waterlogging but the best guess is that until last couple weeks citrus tree could be dry if anything. I read somewhere about danger of overwatering and I watered it only once in a week (as rest of my yard) for 90 min. It is only watering this tree had for a while and there was no any rain here for weeks. My guess would be that until last couple weeks it could be too dry actually. It been raining and I water more often (twice a week for 60 min) last 2 weeks but I saw no improvement so far.
I difinetely check for foilar spray. My dilemma with fertilizer was that on which I was using (Citrus tone) requires to mix it with soil and there is grass around drip line, so I have to use it either too close to trunk or pretty much sprinkle it over grass and hope that tree will get some of it.
I try to post link to pictures.

Here is a link that might be useful: {{gwi:599929}}

more pics
whole tree
http://s003.radikal.ru/i204/1106/a2/24b89c33c549.jpg
bark damage (where previously tag was)
http://s003.radikal.ru/i204/1106/e8/d8d25088f710.jpg
more yellow leaves
http://s015.radikal.ru/i333/1106/e1/779c562cee2b.jpg

Definitely not an under-watering issue, maybe too much water :-) Qwerty, your id line doesn't say where you're located, but for us here in California, we had a long, cold, wet winter and spring. Many of my citrus look like this due to cold temps, too much water, and not enough micronutrients (washed out from too much water and not enough micronutrients in my mainly DG soil). Citrus Tone should be fine, you want to try to achieve a 5:1:3 NPK ratio with citrus if possible. Water it in with some acidified water (use vinegar and adjust the pH to about 5.0). That will help to allow the micronutrients to be absorbed. Also, spray now and again in 4 weeks with a micronutrient foliar spray. I would also check about 6 to 12 inches down to see how wet the soil is. Remove the grass from under the tree, definitely NOT a good thing to have under any tree, especially citrus. The grass will compete for nutrients, and your tree will miss out on the fertilizer. Make sure you've got a nice large well underneath your tree, and fill with compost and/or worm castings, making sure to stay 2 to 3" away from the trunk. Also, not sure how you planted your little tree? Hoping you did not amend the soil, but simply planted in native soil, then top dressed with compost. Also, if you have clay soil, you need to make sure you plant your tree a little higher - the root ball a couple of inches above the soil line. If you're not sure, when you dig a tree hole, you want to dig it twice as wide at the root ball, then fill it up with water. If the water is not all gone by overnight, you've got a drainage issue, and your citrus will not love you for it :-( You'll need to plant the tree higher. The damage to the stem from the tag may pose a problem. It can invite disease to get into the branch, so if it is possible, you may want to prune back to good wood. If not, you can try cleaning the wound with some hydrogen peroxide, allow to dry, then wrap snugly with some grafting tape (Parafilm), which can be purchased at your local orchard supply store or online. That may save the branch. If not, you may need to prune if possible (can't tell if this is the main leader branch, or a side branch).

Patty S.

the veins on the leaves are yellow, could be nitrogen deficiency. your grass is growing too close to your tree. you'll want about a 2' radius around your tree.

Thank you, Patty S. and Houstontexas123,
I did removed grass and fertilized tree. I guess, we will see if it will recover.

Patty S.,
thank you for lots of helpful hints. I live in North-West Florida and we have few cold days during winter when it has been recommended to cover citrus overnight. I did not done it until winter was half-way over and one of my branches died after winter. Otherwise tree seems to recovered and flowered good in spring, just later on I saw the problems. As for planting tree, I just stuck it in native soil and did not do anything else. I did not ever put compost because I read that it is not recommended for citrus. I checked soil and it does not appears to have any problems with drainage. I have banana tree planted not far away from citrus and it has been profusely watered every day for a while. I did not expected that this water could spread to citrus because you yard has some slope which cause all water from banana plant to roll away from citrus but maybe I mistaken and some water from banana tree maybe reaching citrus. I'll try to fix damaged branches (there are actually several around there tag was)