I applied fertilizer with trace elements like 2 months back but my plant still shows iron defeciency.
Thx David[/img]

Do you know (or can you test) your soil pH? If it's above 7.0 (assuming your trees are on citrus rootstocks) or 6.5 (if on Poncirus trifoliata rootstock), you're likely to see iron deficiency, regardless of the amount of iron in the soil, since it is not available to the plant. You could try lowering the pH with sulfur or iron sulfate, or you could buy iron in a chelated form.

In any case, it is not recommended to spray an iron-based material on the foliage -- usually if you get the concentration high enough to do any good, you end up burning the leaves with it. So through the roots is the way to go.

Iron deficiency will also show up if the trunk is injured or if the root system is compromises (due to flooding, etc.).

Sorry, Malcolm,
but I have trees on Volk, Rangpur, SourOrange and even Limes as rooted cutting, and my soil pH is 7,5 up to 8... but I do not encounter iron deficiency.

First of all, I would recommend to post a picture, just to be sure we deal with an true iron deficiency and next we need especilly informations on rootstock and soil... that's what needed.

But in Australia, they grow Poncirus trifoliata on alkaline grounds in replant situations. They treat the deficiency in manganese, iron and zinc by regular foliar applications or those trace elements by spraying it as chelate sprays on and in the tree canopy

Personally, I would follow Malcolm Manner's advice on this subject. - Millet (1,108-)

Lack of trace minerals can cause leaves not too green or not enough nitrogen. I apply STEM to the leaves every time I spray in the summer and the leaves really green up dark. I'd be happy to mail you a pound for what I paid + shipping. I had to buy 25# which is enough for 10 lifetimes.

http://members.fortunecity.com/pjsauber/Citrus%20deficiencies.htm

i am getting mixed feelings on what is actually wrong with my citrus.
it has some dead twigs randomly everywhere and i am seeing that asian something bug on all of my new growth right now .(Citrus greening) i dont know
heres a link to a picture of my lemon tree
link
let me know what you think there

Millet,
you can get close to Malcom, but it won't change my experience.
It's a good advice to keep the trees and those ph levels, but if you cannot or do not what to... well.... you can do, if using ph tolerant rootstocks.

But on the picture, well, I haven't seen any greening personaly, but those leave symptomes I found myself on salt problems. If the ground contains to much disoved salts, the tree roots get damaged and such leaf symptomes get visible...

Steve, I'm not sure how I've insulted or angered you, but I'm truly sorry if that has happened. I hope we're not enemies! And congratulations on your healthy citrus. I don't doubt your observations on your trees are true.

However, my advice was not my opinion; it was the result of more than 100 years of research in Florida's citrus industry, and at least under our conditions (which I fully realize are different from yours), it is incontrovertibly true.

Malcolm

malcolm would you be able to agree with that there are some high slat levels in my soil. or do you think there is another issue and anything to fix it would help
thx david

The second photo, of the avocado tree with the dying leaves -- high salts was my first thought there, although it bothers me that some leaves are so badly affected, while others are not. Might this plant have been over-fertilized, and then the excess salts washed away later? I'm not sure what else would show that situation.

On your citrus trees, I see no indication of too much salt, although there certainly could be. I think Millet is right that the first one is showing fairly strong magnesium deficiency (perhaps along with a bit of biuret toxicity?? Does your fertilizer have a lot of urea in it?), and that the last one is fairly typical manganese deficiency.

Magnesium can be corrected as suggested above, with epsom salts applications to the soil. OR you could use a very dilute foliar spray.

Manganese deficiency, on the other hand, is difficult to correct with soil applications, even if the soil pH is nearly perfect -- it's a slow process, requiring multiple applications over a long time. However, it can be corrected very quickly with a dilute foliar spray. So for those two elements, I like the idea of foliar spray.

I don't see specific symptoms of iron deficiency in these photos, although the other deficiencies could be masking mild Fe deficiency, I suppose.

Malcolm

In Florida's soils that are naturally at a pH above 6.5, we use very little Carrizo, Swingle, or other hybrids, and almost no Poncirus at all. It's just not worth it. Fortunately, most of the soils on which our industry is based, are naturally down in the pH 4.5 range, so we bring the pH up with generous use of liming agents, mostly dolomite. For the hybrids (especially Swingle), we'd like to stay BELOW 6.5 -- 5.5-6.0 is far better. For true genus citrus rootstocks, higher is acceptable, but as it approaches 7.0, we will see nutrient deficiencies, which may require foliar sprays (and therefore added production costs.) While the numbers 6.5 and 7 appear to be quite close to each other, in the actual chemistry of the soil, there is a huge difference in micronutrient availability between those two.

The one reason we sometimes recommend getting closer to 7 in a grove is if it has received an abundance of copper-based fungicidal sprays over many years, so that the copper load in the soil is high. A higher pH will fix that Cu in the soil, so that the tree is not injured by it.

Well Malcolm,
but there are commercial ochards even in grounds with ph well above 7.5, as far as I know... and I guess premium Grapefruit are usually grown there....

So most of the ochards are in the acid soils, but there are some ochards in alkaline soils in a very good production. And I guess there is no spray need, if you use non-trifoliata stocks....

And if you look beyond the large pool of water to israel, morocco, sicily or tunesia, you will find even here commercial ochards in high alkaline soils, usually by limestone saturisation.
Even here, usually no micronutrient sprays are neccessary, because the right stock is in use.
These circumstances we can also find in Texas and Arizona, were we can find such alkline soils widely planted commercially...
And even here, usually no etra nutrient sprays are needed.

That's what I am informed of, and for Israel, Tunesia, morocco and italy I have no doubt that the informations are true.

Steve,
Yes, a few areas would have soil pH levels above 7.5, up to about 8.3 in a few areas of south Florida. Most of those areas no longer grow citrus, due to canker and greening, but when they did, they did so with genus Citrus rootstocks, heavy use of chelated iron to the soil (Sequestrene 330 Fe or similar for pH around 7.5 or Sequestrene 138Fe or similar for higher pH -- an astounding expense), and other micronutrients (at least Mn, and Zn) applied as foliar sprays, at least once and often twice a year. Magnesium can be soil applied for rough lemon rootstock; in most other cases, though, Mg is also applied in foliar sprays. I've also worked with citrus growers in Egypt, and found much the same thing. I'm not aware of such an area where micronutrient sprays are not used; certainly they are "standard" in US agriculture in high-pH soils. I'm not sure where you may have heard that they are not used, but they are.

Well, Malcolm, here we start to split in experience and in knwoledge. In deep respect: I first had to watch in my books, to give you reference, before I post here out of the box (memory) right now.
But I will get back, if I got the informations together, with the references for you.

"The end of higher education is, not to believe in anything written!"
But here we need a basis, a foundation, to share experience and knowledge... something to start from.
And that's why a first had to do the reference works.