I would like to ask You what happened to my citruses leaves? I have two opinions:
1) All my citruses have suffered from overwatering.
2) My citruses have a defect of some nutrient.

Here are some pics that i posted.

calamondin:


canton lemon:


unshiu:


orange:

Looks like nutrient deficiency.

What is your fertilizer and schedule?

How do you water?

I believe your tree has the symptoms of an iron deficiency. Iron is a mobile chemical in citrus trees, so the symptoms of an iron deficiency always show up on the newest leaves having green veins on an otherwise yellow leaf. Manganese deficiency also looks much the same as an iron deficiency. The difference between the two is with an iron deficiency only the vein is green, plus there is no additional green border area along the side of the vein. The symptoms of a manganese deficiency also shows up as green veins on a yellow leaf, but the green veins also contain a wider green boarder along the vein's edge. Anyway, your tree presently is showing only a slight deficiency, and should be corrected rather easy with the addition of either Iron Chelate or Iron Sulfate applied to the tree's root zone. Do not apply Iron additives as a foliage spray, as this can cause leaf burn. Good luck to you and your tree. - Millet (902-)

Thank Millet for helping and good wishes! The watering of my citruses depend on weather because all my plant stay outdoor in the pots.

mgk65, the fertilizers name which i use is "Kemira Luks". It consists from:
N - 16%
P- 20,6%
K - 27,1%
Fe - 0,1%
B- 0,02%
Cu - 0,01%
Mn - 0,1%
Mo - 0,002%
Zn - 0,01%

Tell me, please, what is wrong with those leaves?

Maybe zinc deficiency?

Thanks, Evaldas! It looks like zink, but i doubt between zinc and manganese?

Ok. Thanks Mark! I fully understand what is the problem of troubles with leaves. But i have to ask what is the best ratio for micronutrients?

I'm sorry in case if this question was answered in this forum before.

Well if it's either zinc or manganese and you didn't find, after carefully inspecting, any pests, you should treat for all micronutrient deficiencies with micronutrient fertilizer that contains no NPK, and only micronutrients in chelated EDTA form, the ratio is not as important. You will only see results on the new growth or the leaves that are only 2/3 mature, the older leaves will stay like this until they drop.

Iron and nitrogen deficiency.
You also probably have mites. Visible on the Unshiu and the orange.

Definitely not zinc, since sufficient deficiency to cause that much discoloration would also result in severe dwarfing of the leaves, and these appear to be nearly normal size. I tend to agree with nitrogen and iron; perhaps also sulfur. But I do wonder why those would show up together, on one growth flush -- that could mean some form of severe root damage (root rot, nematodes, water damage, previous drought, etc.). Is that a possibility?

Malcolm

serj, looking at the fertilizer that you are applying to your citrus trees, I notice it contains 16% nitrogen and 0.1% iron. If you are fertilizing the tree on a regular basis the tree should be receiving plenty of both elements. Does your water have a high Ph (above 7 or ? A high Ph can explain an iron problem, but not the nitrogen problem. What is the source of the N? I also notice that your fertilizer contains a very high level of phosphorus, which is out of line for containerized citrus trees. Further, the formulation contains no magnesium at all (which is not all that unusual for formulated fertilizers). However, I assume that you are aware of the absence of Mg, and are adding magnesium sulfate (Epsom Salts) 3 to 5 times a year. - Millet (896-)

Sylvain, i completely agree with you! I have treated my citruses twice by "antimites" preparation "Aktelik".

Malcolm_Manners, it was rained every day. Maybe overwatering?

Millet, i fertilized all my citruses in addition by elixir from grass and H2N-CO-NH2 and K2SO4·MgSO4. Maybe there were too small quantity of fertilizers that i used? Maybe some part of fertilizer is extracted with water in case of owerwatering?

P.S. Sorry for my bad english! I learn English by self-training.