When  the medium dries out the tree and fruit also dry down (become thirsty)  Adding a lot of water to the medium the tree starts drinking quickly.  This causes the fruit to take in water and drink rapidly.  The fruit's peel cannot expand as fast as the water comes in, and the fruit burst (cracks)  What is best is to keep the medium evenly moist.

By the way, I say a post where you are having trouble getting pineapples to root.  I grow a LOT (50 at a time) of pineapples in my greenhouse here in Colorado, both in ground and in containers.  The procedure is to break off a slip  from the mother plant, then peel of the bottom leaves until you have a 2 to 2.5 inch clean leaf free stump.  Then set the slip on a open air bench in full sunlight for about a week to cure (IMPORTANT). Actually pineapples are an amazing plant.  You could actually leave a slip say out in the open air on a bench for a month, and it will still grow.  This cures the slip and also stops the slip from rotting when planted.  Then go ahead a stick the pineapple slip in either the ground or a container.  You should have about a 90 to 95 percent rooting. 

he USDA is NOT doing stings.   The USDA is trying  desperately trying to control greening (HLB)

USDA = United States Disease Association ??

Looks more like a Manganese deficiency.  Manganese deficiency is common in newer leaves, but the tree normally cures the deficiency on it own.  This type of deficiency is not all that uncommon.  You can treat it if you wish, but I would do nothing and just wait and watch it.

Laidback, just keep watching your fruit, and then you will know the maturity date  in your area.  The very best to you.

This topic has been moved to Tropical Fruit Discussion.

http://tropicalfruitforum.com/index.php?topic=41103.0

Laidbaackdood, ugly fruit look nothing like your fruit.  Ugly fruit are round and pretty much smooth like an orange.

Citradia, several citrus expos back (Alabama) they sold a plastics air layer kit.  Is that where you got yours.  Your graft looks great.

Poncirusguy, in my estimation grafting to Sour Orange in your area is one of the best rootstocks you could use.   Sour Orange produces fruit of high internal quality. Overall an excellent rootstock with broad soil adaptation and disease resistance, with only the exception of Tristeza virus, which you do not have in your area.                             

There if nothing wrong with using pine bark in a growing mix.  Very many growers use the 5-1-1 mix = 5 parts pine bark , 1 part peat and 1 part sand or perlite. A 5-2-1 medium is also a good medium.  Laaz uses a 50/50 mix of Turface and peat.  In reality, it is not the water that does damage to citrus roots, what actually causes damage is the lack of oxygen.  Citrus can be grown in pure water, as in hydroponic culture.  What is of up most importance that the medium is a free draining medium that provides a higher level of root zone oxygen, while still providing proper amount of water.

I would send the seed.

Zitrusgaertner, thanks for the information.