i have 4 citrus planted in ground and 2 of them have leaves that are yellowing, the other 2 are fine. the 3 year old grapefruit is the older leaves while the new growth looks fine, and the 2 year old tangerine is the new growth yellowing and the old stuff is fine. ive looked around the web and havent come up with anything great to cause this. my best guess is a mg deficiency, any better ideas?


thanks

red

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In my opinion, neither tree is deficient in Magnesium. The leaf symptoms are not consistent with a Mg. deficiency. The tangerine could be deficient in iron (still the leaf pictures is a little strange). Iron deficiency symptoms appear on the NEW leaves, with green veins and otherwise yellow leaf (no green border area around the veins). To correct an iron deficiency apply iron sulfate or chelated iron to the root system, by applying to the surface of the ground. - Millet (993-)

thanks millet, i actually picked a bad example of a leaf for the tangerine. i think that particular leaf has other issues also. the rest are more normal looking although yellow. well until further notice ill treat for iron deficiency. what gets me is that i have 3 trees within 50 foot of each other and 1 is fine and 2 are showing different symptoms. the soil cant be that different in my back yard...

if you think itll help you i can get a full tree pic up tomorrow



thanks

red

Yellow leaves can be cause by several deficiency symptoms.

Nitrogen: Shows up on OLDER leaves with newer leaves still being green. The deficient, depending upon the severity shows up as totally yellow leaves, with no variation of color, or yellow-orange veins with some green out on the far sides.

Manganese deficiency: NEWEST leaves with green veins, with green border areas to the sides of the veins on an otherwise yellow leaf.

Magnesium deficiency: OLDER leaves lower center portion of the leaf has a green delta shaped coloration, and tips and sides of the leaf are yellow.

Iron: already stated above.

Millet (992-)

It could be a zinc deficiency although from the pictures it looks mild. I have some leaves on potted citrus with zinc deficiency.

At the end if this great link, there is an appendix with pictures of the various deficiencies.

link

thanks for that great link. after looking at the pics im still thinking the tangerine may be MG deficeint. many of the leaves have a bit of that chrismas tree effect going. im still stumped about the grapefruit though. for a while i thought it might be greening disease but the pics dont match up at all, most of the yellowing is symmetrical. ill add better pics of more leaves tomorrow, its raining a bit now, pics wont come out well.


so i went ahead and treated with iron sulfate. i added 1lb to both trees. how long before i see some sort of difference, or can rule that out as the problem and move on to the next mineral issue??? and if it does work how long will it last, will i have to add this to my trees every spring, or only when i see symptoms???


thanks

red

Have you checked pH? A high pH can limit uptake of minerals.

As for treating iron deficiencies, Ferrous Sulfate will only be available for a short time--as soon as the iron is oxidized (Fe+2 to Fe+3) it will become insoluble and mostly unavailable for uptake. Chelated iron will remain available much longer.

no i have not checked the ph yet. that will be on my to do for this weekend. where can i find chelated iron, garden centers????

heres some better pics. first 2 are grapefruit, 2nd are tangerine



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Perhaps the third picture could "possibly" be a magnesium deficiency, but I don't think so, especially if the leaves pictured are the tree's newer leaves. A magnesium deficiency shows up on the OLDER leaves of the tree. As I cannot see the entire tree, I am not 100 percent sure, if I am looking at the tree's new or old leaves, however, but I think the leaves shown are pictures of your tree's newer leaves. The leave symptoms look to be a manganese deficiency . Just a note: Joe Real's AZ41, must supply manganese, as one spray of his product, corrects manganese deficiency quickly, while at the same time eradicating scale, mealy and aphids. - Millet (987-)

The first two pictures might be a zinc deficiency. Are you using a fertilizer that includes the micro nutrients like Zn,Mn,Mg,Ca,Fe? Excess potassium
in soil can lock up Zn,Mg, and Mn. Some fertilizers only have nitrogen, phosphate, and potash.

One of the main symptoms of a zinc deficiency, (along with the green veins with green borders), is the greatly reduced size of the leaf. The leaves shown are of normal size. - Millet (985-)

where can i find this AZ41 stuff? looks like its only online and/or through him?


all i can find local is some 13-13-13 with iron and sulfur added i beleive. i did buy another small bag of fert that had the trace elements in it and gave each of my trees either one pound or two. i guess that that wasnt enough for either of them

I apply a handful of a trace element mix to my trees every yr. Our sandy soil is very mineral poor. I get the mix at an Ace Hardware garden center--I buy a 5 pound bag for about $6.

I know Peters makes a product called STEM (soluble trace element mix), but I think it only comes in 25 pound bags.

I would check pH first--then add trace elements.

i guess i didnt look hard enough the first time i looked, but these are the leaves on my owari satsuma. its real light and subtle which is why i didnt see it the first time. millet, is this the green borders around the veins you talking about??? seems like its slightly different than the others either way...

whatever it is, its affecting them all within 35 feet of each other, im definately going to test my soil this weekend. ill let yall know the results.


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