Established Cogshall, with what I assume is a bad fungal problem.  I've sprayed the tree twice in the past two weeks with Southern Ag Liquid Copper Fungicide, using the recommended dosage of 4 teaspoons/gal.  The tree is also starting to send up pannicles.  The photos are about a week after the second treatment.  I'm not seeing much improvement.
A Pickering, not too far removed from the Cogshall, has no fungus.
What am I looking at and how best to eradicate it?

Thank you for the replies.  I have some Southern Ag Liquid Copper.  I'll give it a treatment or two and see what happens.

Ugh.  What causes this?  How best to treat it?

Took a thorough look at both trees and didn't find any insects that might be the culprits.  I have to agree with Cookie Monster on this, at least for my trees:  new growth followed by some rains, resulting in a fungus. 
Should I let 'em be and let nature take over?  Or should I cut off the affected growth to help inspire new growth?  If so, where to make the cut?

Two or three weeks ago my two mango trees, a Cogshall and a Pickering, both put forth a growth flush.  But on both trees the new growth has all turned black and shriveled.  Never had this before.  I'm guessing fungal issue?

Last season my Cogshall coughed up about 100 mangoes.  First time it ever produced such a bounty.  It's a mature tree, inground for about 6 or 7 years now, and about 15 feet tall.  This season. . .not one pannicle produced.  In mid July last season I did cut her back about three feet all around since it was getting a bit big for where it was planted.  Could this be the reason for such a drop off in production?  Is the Cogshall susceptible to alternate bearing fruit production? 

A friend about 5 miles from me told me her mango tree is completely dormant as of a few days ago.  In my immediate neighborhood there are a number of trees that had early and heavy blooms.   

My Cogshall is as dormant as Rip Van Winkle; my Pickering, (second year in ground from a 3 gallon pot), sent up one pannicle about a month ago and looks like it's getting ready to send up a few more.

No, you're not missing anything, Mark.  I think the University of Florida needs a capital infusion, so they scammed me for $12. 

I have posted pdfs before on the old post image set up.

I'm sure it's me, but Google Drive worked fine.

I sent a soil sample to UF in Gainesville last week.  Results came back today and I'm very surprised at the readings. . .unless I'm misinterpreting things.
A little background:  the soil was taken from about 8 different locations around the mango tree, at the surface and a maybe a few inches below.  The tree in question is a Cogshall, inground for about 7 years now.  Well established.  Never water it.  Reached about 18'.  After harvesting the last of the mangoes two weeks ago, (around 100), I trimmed the tree back.  Took about 4 feet off the top branches and tipped all around the tree.  Flushing like crazy right now.  Don't know if it's related, but many of the fruits suffered jelly seed this season, and last summer, too.
My fertilizer routine:  after harvest I sprinkle some 8-3-9 with minors around the tree.  Follow up with a second feeding around a month later.  Starting in September I'll feed some 0-0-50 and again in October.  When I see the leaves looking like they are hungry for some minors and/or iron, I'll give the tree some Southern Ag Chelated Liquid Iron and some Citrus Nutritional.  Sometimes a drench, other times a foliar feeding.  That's the extent of it.
But now this soil analysis comes in and everything seems to be off the charts high.  Hoping some experienced eyes can take a look and offer some feedback. . .but first I need to figure out how to attach a PDF to my post.

Apparently they have a program targeting the Mediterranean Fruit Fly and are scattering traps around.  He asked to place a trap on my property, (Central Broward County), in an Orange Blossom Jasmine we have in front.  Sure, why not?  I recall the battle I had with the papaya fruit fly a few years back.  Anything for the cause.

So you're picking them rock hard and green?  Are they coloring up any indoors, the green showing some yellow after a few days?  How much give are you feeling at that time?
I just pulled a few big ones off the tree, earlier than I would normally.  I'm going to keep my eye on them for a few days and see what the results are.