What causes yellow leaf margins/veins on Citrus and Sapodilla?

[barath]

I've been puzzled by a strange coloration on my citrus and sapodilla leaves -- leaf margins/edges and veins (and only the margins and veins) are yellow, and the rest of leaf is deep green.  The leaves definitely don't look like what I've seen on healthy citrus and sapodilla, but I'm not sure what might be causing this.  Both are in containers and are fed periodically with generic organic fertilizers of various types.  Has anyone seen this sort of problem?

[FlyingFoxFruits]

Some sort of deficiency, sorry I dont know which nutrient is lacking, but give them a micro nutritional spray, maybe in conjunction with a chelated Fe drench, I bet this will make things right.

[michsu]

Probably a Sauce Bechamel with a reduction of red wine, shallots, and poached beef marrow would be better.  but be sure to spray some Dynagro first on the leaves before doing this..

[cbss_daviefl]

The general rule is that if the yellowing is blotchy and random looking, manganese is the issue.  If the yellowing had a distinct pattern and the center is green, magnesium is the issue.  Best to follow Adam's advice and give a general foliar feeding and drenching.  If it is deficient in one, it may be close to deficient for other micros too.

[simon_grow]

I agree with what others have already stated and in addition to that, I would also recommend adding some sulphur granules which will very very slowly decrease the pH of your soil. I would also do a soil drench with pH Ed water because it is very likely the cause of your micronutrient deficiency is caused by too high of a pH of your soil. I also had similar issues with my citrus and have corrected the issues with the advice I just gave.

If you have the time and resources, of course I would recommend hiring a professional to test your soil and plants to determine the cause of the yellowing because it can also be caused by virus or too much of something but few people have the time nor resources to do this. You live in California so there is a good possibility your soil has a high pH somewhere in the neighborhood of 8.0 which does not easily allow for the uptake of certain elements. I personally use pH down which can be ordered online or at a hydroponic store to bring down about 5-10 gallons of water to pH 5 or so and drench my soil with that. With the buffering capacity of my soil, this will bring my soil to around 7 or so but of course this will depend on many factors, it is better to bring down the pH slowly.

Aside from your likely high pH soil, your water source is likely high too. Mine is pH 8.2 so every time you water, you will bring the ph of your soil back up so it may be wise to drench your soil with low ph water once a month or so which seems to be enough for my citrus to keep them happy.

A thick mulch layer will also be very beneficial.

Simon

[bsbullie]

Use tiger eye sulfur.

[Cookie Monster]

You can get accurate ph testers online for around $60. I got an ecoTestr ph2 -- been very happy with it. Or you can send your soil off to a lab, which runs like $15.

(Heavy) mulching / compost is very effective at bringing ph to neutral. I used close to a thousand cubic yards of tree trimmer mulch so far, and it's had a dramatic impact. This is probably the only permanent solution to the problem.

Sulfur works too (temporarily). I'm currently experimenting with super high doses (~5 tons per acre). So far no detrimental effect to the existing plants after 2 months.

[bsbullie]

Depending on a lot of factors,  broadcast sulfur application can have a lasting effect for years.

To clarify,  the sulfur should be broadcast over you entire yard like fertilizer.

[barath]

Great -- I'll add some micronutrients (probably as kelp / fish emulsion) and see how it goes.  I've added sulfur and cottonseed meal in the past to lower pH so I think it should be acidic enough now.  Thanks!

[bsbullie]

Great -- I'll add some micronutrients (probably as kelp / fish emulsion) and see how it goes.  I've added sulfur and cottonseed meal in the past to lower pH so I think it should be acidic enough now.  Thanks!

Did you add the sulfur to the entire yard or just the tree (s)?

I wohld seek out a better form of micronutrients fertilizer.   One that contains a full spectrum.   Fish emulsion and kelp will most likely not be sufficient.

[jcaldeira]

The yellow leaf vein problem may be due to low phosphorus.  I had a similar problem on part of my farm and it turned out to be low phosphorus, possibly made unavailable to the plants due to high copper or some other mineral.

I reported my problem in this thread (see reply #30):
http://tropicalfruitforum.com/index.php?topic=9236

[barath]

bsbullie -- it's a container garden, so everything is in medium to large size plastic pots.  (Both the citrus and sapodilla have good drainage.)  Do you know of any broad spectrum micronutrient sources that are organic?

jcaldeira -- I'll see if it's phosphorus.  The weird part is that the leaves themselves are solid green -- it's just the edges and veins that are yellow.

[Mark in Texas]

bsbullie -- it's a container garden, so everything is in medium to large size plastic pots.  (Both the citrus and sapodilla have good drainage.)  Do you know of any broad spectrum micronutrient sources that are organic?

jcaldeira -- I'll see if it's phosphorus.  The weird part is that the leaves themselves are solid green -- it's just the edges and veins that are yellow.

It's not low phosphorous, quite the contrary.  High P induces micro deficiencies.  It is an antagonistic element.  http://www.ces.ncsu.edu/depts/hort/consumer/quickref/fertilizer/nutri_def.html

Your leaf chlorosis is a micro deficiency, probably Zn or Mn.  There are some great citrus sites that have colored photos regarding such deficiencies.  That's where you should be doing your research.

Foliar sprays of Keyplex will correct those deficiencies. 

[simon_grow]

Epsom salts are also a great greener for citrus in California.

Simon

[Bush2Beach]

Barath, you can try "Down to Earth " micro nutrient spray to correct the problem. Watering with "PH Down" can help when rain water is unavailable.

[Guanabanus]

For "National Organic Program compliant" micro-nutrient mixes, check out the Brexil brand from Italy--- some, but not all, of their mixes  are "organically approved" (my term). Most are chelates from Ligninsulfonates (not EDTA).