Mine look that way as they transition to emerald green. Are the others elders staying green?

pj, after two months I have to think the leaves should be uniform in color, the usual dark green throughout.

It's chlorosis due most likely to iron deficiency. Get some southern ag chelated citrus nutritional spray and spray it 2 or 3 times over the summer. You could also drench the soil a couple of times with Miller's Ferriplus 138 or something equivalent. If you have alkaline soil, it's useless to give your trees granular micronutrients - must use chelated.

Jeff

PS the cogshall is stinkin' delicious... easily superior to the glenn in my opin.

Jeff

I agree with Jeff.....on both counts.

Harry

Thanks for the info, gentlemen. I'm going to a local nursery to score some product. I'm determined to be eating some home grown Cogshalls next summer!

By the way, would it be better to treat the problem, alkaline soil, as opposed to treating the symptoms resulting from that soil?

The problem with the soil here in south florida is that we have a layer of oolitic limestone just under the top soil. If you can get rid of that and replace with something more neutral (eg, compost), then you can successfully treat the alkalinity issue. I've done that in my yard, but it is a significant effort. You need to dig out a good 15-20 foot diameter hole, otherwise you run into the chlorosis issue as soon as the roots hit the limestone again.

Jeff

Jeff, as always, thank you for the timely info.
Clearly, then, altering the soil isn't practical. Meaning I need to treat the symptoms, which is to feed the plant the necessary minors.
That said, I would prefer to find a soil drench as opposed to using a foliar treatment. I've used Southern Ag's Chelated Citrus Nutritional Spray in the past and have burned the leaves badly. Used it at half strength, too. So I'm skittish about foliar sprays now. Can you recommend a product? An online search hasn't produced anything yet.
Thank you.

OK. I haven't had the leaf burn, but I always spray after sunset. If you're near Homestead you can pickup a pound of Miller's Ferriplus 138 at AFEC (18375 SW 260 St Homestead, FL. 33031). Or you can just order a bottle from ebay.

Carbos, maybe you can look into Ironite Plus? Do some research and see if it might work for you? I've used it a couple of years ago and had good results. I can't remember if I applied it once or twice...should have the directions on the package. I remember watering it or waiting for rain(not heavy rain) or it will all wash away.

Spraying with chelated iron after the sun sets is definitely the best way...this way it has all night to dry completely.

Here is a link that might be useful: Ironite Plus

puglvr, thanks for the suggestion. I hadn't thought of Ironite, despite seeing it on store shelves all the time.
I did some research and I am thinking of trying their IRONITE Plus Liquid Plant & Flower Food 7-6-6. It's a liquid concentrate that is added to water and then used as a soil drench. I'm leaning towards the drench because of a previous bad experience with a foliar spray, but also because Jeff mentioned above that with an alkaline soil it is useless to apply granular micronutrients.

Make sure whatever you use is chelated. The growers here use a chelated iron product (eg, Sequestrene 138 or Miller's Ferriplus 138). I don't fully understand it, but the chelated iron is in a particular chemical state such that it has low affinity for the abundant extra positive ions in alkaline soil and is therefore available to plant roots. The problem here isn't that our soil lacks iron - it's that the iron that's there is in an unusable (chemically bound) state. The terrible alkaline oolitic limestone is only an issue to parts of broward and dade county as far as I know. Palm Beach and northward have near-neutral sand.

Jeff

Then that rules out the Ironite, since I don't see anything on the product label that indicates the iron is chelated.
Does the Miller's Ferriplus 138 also contain some of the minors?

I honestly don't know if the ironite is chelated. Ferriplus doesn't have minors, but the biggest problem is usually iron. Dr Campbell's recommended fert routine is basically just two things - iron (drenches) and potassium (granular) :-). But if you did want minors, AFEC has a host of chelated products, including Fer-a-grow, which is what Whitman used way back in the 60's (according to his book).

Jeff

Jeff, thanks for all your help. I'm looking into a variety of products that might fit my needs. I'm finding many are geared towards large growers and so the quantities they are offered at are overkill for my one puny tree.
I do see that Southern Ag offers a Chelated General Purpose Minor Element Spray which might be applicable as a soil drench:

CHELATED GENERAL PURPOSE MINOR ELEMENT SPRAY
� Can be used on all plants including lawns
� Contains 6 important nutrients including iron
� Prevents & corrects deficiencies that cause yellowing
CONTAINS: Iron 2.75%, Manganese 1.00%, Zinc 0.50%, Magnesium 0.50%, Copper 0.25%, and Sulfur 3.8%.

USE ON: Flowers, shrubs, trees, vegetables and lawns

CONTROLS: Minor element deficiencies, yellowing of foliage, etc.

NOTE: Deficiency symptoms can be caused by improper soil pH.

RATE: Foliar: 1 tbs. per gallon of water drench: 1 oz. per 100 sq. ft. Lawns: 1 pt. per 1,000 sq. ft.

APPLICATION: Mix with water and apply as a drenching spray.

I'm going to look into this further.

Ohh nice. That looks like a good one. They sell Southern Ag products at Home Depot / Lowes.

Jeff

Just heard back from a rep at Southern Ag. He assured me that their Chelated General Purpose Minor Element Spray can be used as a soil drench in additional to being used as a foliar spray. Recommended dosage is 1 tablespoon per gallon of water. I'm going to wait to hear back the results from the soil sample I sent to Gainesville and then get at the problem.
Thanks for all your help, Jeff!

Thanks for all the great info.
Marin

Here's a good FSHS article on iron deficiency in limestone soil (like that found in parts of broward and dade counties). They indicate that iron sulfate is useless because it rapidly binds with calcium, and iron products with acidifying ingredients also don't work because "buffering capacity in the alkaline range is virtually infinite". They recommend miller's ferriplus or sequestrene 138. One interesting point that they make is that foliar sprays of iron are not as effective as soil drenches due to lack of absorption through the leaves.

Jeff

Jeff, thanks for the follow up and link.
As a matter of fact, yesterday I ordered through an EBay seller a bottle of that Southern Ag Chelated General Purpose Minor Element Spray. I could not find it locally at any retailer.
I'm going to use it as a drench at the recommended rate of 1 tablespoon/gallon. Hopefully, it will do the trick.

Just received the soil test results back from the University of FL. No surprises. The PH level is quite high, at 7.6, and that the soil is calcareous in nature.
They also recommended the addition of phosphorous at a rate of .40/lbs per 1,000sf.

OK that's interesting. I bet if you scooped up some of the limestone rock down beneath the top soil and sent that to them, the ph would be off the charts :-).

Jeff