Pale Leaf Mystery

[Felipe]

I also think there is lack of Fe, maybe also micronutrients. Very important: Check the ph! Maybe there are high levels of lime in this part of your orchad.

Hello Felipe! How can i correct ph in a lime region? Thank's!

A long term solution is adding big ammounts of organic matter to the soil: Mulch, compost, but also acid manure (chicken).

What really doesn't solve the problem, but lowers the ph temporary is adding sulfur or acidic fertilizers like ammonium sulfate. At the beginning you can make both things, but I recommend you going the long term organic way

[Luisport]

I also think there is lack of Fe, maybe also micronutrients. Very important: Check the ph! Maybe there are high levels of lime in this part of your orchad.

Hello Felipe! How can i correct ph in a lime region? Thank's!

A long term solution is adding big ammounts of organic matter to the soil: Mulch, compost, but also acid manure (chicken).

What really doesn't solve the problem, but lowers the ph temporary is adding sulfur or acidic fertilizers like ammonium sulfate. At the beginning you can make both things, but I recommend you going the long term organic way

Thank you so much for all advices!

[Guanabanus]

Multiple-nutrient deficiency, but especially deficient in sulfur (which you didn't mention test results for), and Zinc.

Apply about 1 pound of sulfur around each tree, in a wide band, from about 3 feet out from the trunk to 8-10 feet out from the trunk.  If you use powder, spread in no wind on dewey or rain-wetted ground.  Protect your eyes, nose, and hands.  Water in.

For zinc, follow label.

[jcaldeira]

Multiple-nutrient deficiency, but especially deficient in sulfur (which you didn't mention test results for), and Zinc.

Apply about 1 pound of sulfur around each tree, in a wide band, from about 3 feet out from the trunk to 8-10 feet out from the trunk.  If you use powder, spread in no wind on dewey or rain-wetted ground.  Protect your eyes, nose, and hands.  Water in.

For zinc, follow label.

Thanks for the suggestions.  The original soil test did not report on sulfur.  I'm still waiting for the soil test results on this specific area of the farm (maybe this week).  I'll ask about sulfur.

[Saltcayman]

Yeah I agree with Har. add zinc and sulfur.  If your ph is low in that area,  you may not need to spend money on chelated iron. Regular iron sulphate should work as a foliar or soil drench. Do you have seaweed/seagrass available? Mulching with that should add organic material and micros over time.  Dave

Multiple-nutrient deficiency, but especially deficient in sulfur (which you didn't mention test results for), and Zinc.

Apply about 1 pound of sulfur around each tree, in a wide band, from about 3 feet out from the trunk to 8-10 feet out from the trunk.  If you use powder, spread in no wind on dewey or rain-wetted ground.  Protect your eyes, nose, and hands.  Water in.

For zinc, follow label.

Thanks for the suggestions.  The original soil test did not report on sulfur.  I'm still waiting for the soil test results on this specific area of the farm (maybe this week).  I'll ask about sulfur.

[jcaldeira]

I finally received the soil test results for the 'sick' area of my farm.  Here's what I find:

Available Phosphorus is extremely low.  Ideal is between 20 and 30 mg/kg.  The overall farm is 4.1 (low).  The problem area is 1.0, extremely low, at only 5% of the minimum ideal range.

Copper is extremely high:  Ideal is >0.2 mg/kg.  Overall farm is 0.1 (half the minimum ideal).  The problem area is 4.0.  So it's much, much higher than my overall farm.  The problem area is on an old lava flow, so it could be leaching from the rock. 

pH, nitrogen, calcium, magnesium, potassium, sodium, iron and zinc are all good.  Manganese is very high, but not much different than my overall farm.

Right now I'm leaning towards a phosphorus deficiency, but the leaves on my tree do not match the internet photos for potassium.  Another suspect is copper toxicity. 

A third possibility is that the soil in this area is ideal for some root-rot causing organism.  I'm tempted to dig out a plant to check.  I moved two young affected Malay Apple trees from that area to another and they improved greatly.

[Guanabanus]

Very interesting.   The Copper and some of the other nutrients may be "tied up" with each other.

[jcaldeira]

Very interesting.   The Copper and some of the other nutrients may be "tied up" with each other.

That's exactly what the CEO of Fiji's primary fertilizer company is thinking.  He analyzed my soil results and thought that the very high levels of some element(s) are probably tying up the phosphorus, making it unavailable to the trees.  The soil is extremely high in magnesium, iron, manganese and copper.

He recommended I apply a superphosphate fertilizer, and concentrate it in one or two areas under each tree instead of broadcasting it.  He thought that gave a better chance that some would be available to the tree roots.  I had never heard of this way of applying, but he swears it works better than broadcasting in this situation.  I applied the fertilizer this morning and am waiting for rain now.

John