another view

another view

Last year was a bad year for mangoes for me also and my tree usually does very well. I think it was the weather. I usually fertilize when I see the pannicles.

Here's a link that may help. Other than that, it seems that where your tree is planted is very restrictive, considering the size of the tree. Maybe you should check with a certified arborist?

https://edis.ifas.ufl.edu/mg216

I am having a similar problem with my 10 ft tall Kent mango tree that was planted 5 yrs ago in my backyard. The only difference is that I haven't had the many pannicles your tree shows.
Was going to just do nothing this year even tho maybe a dozen or so small pannicles have emerged within the last 10 days. However, just yesterday I received some advice from a respected website and did something I never did before. This website advises applying one fistful of 0 - 0- 50 fertilizer for every inch of trunk width measured one foot above the ground. This should be done twice a year, in February and again in April. Realizing that was basically NOW, I drove to a quality seed nursery nearby and bought a 5 lb bag of " Sulfate of Potash " for $10.95,...which the lady behind the counter said is indeed, the 0 - 0- 50 fertilizer my experts suggested. She also advised applying it now, as it had already rained here 2 hours earlier and was supposed to rain again later on.
I agreed with her,..it's almost Feb anyway, so applied seven handfuls of the fertilizer around the trees' drip line before it got dark. Then sure enough, it rained twice again after it got dark. Will of course repeat this in late March or April.
The website that clued me in is below if you want to peruse it,..has lots more info as well. But this will be all I do at this time, except adding 6 or 7 shovel-fulls of some organic compost to each tree from my bin in rear of the yard, that'll be it ! Keeping my fingers crossed it'll make a difference and enable me to finally harvest some delicious Kents in July. Good luck !

http://southfloridahorticulture.com/mangos/

The UF site (edis.ifas.ufl.edu) is a great resource! Tons of info there.

I have a Keitt planted 8 yrs ago that had best crop ever last year despite its ongoing Anthracnose issue. I kinda made it a mission after nada or almost nothing every year. Put a wide tree ring around it, filled with pine bark mulch, fertilized it monthly Jan-July (Citrus tone 5-2-6) and alternated spraying copper, neem every 2 weeks or so Feb thru early summer. It had lots of drop off (nubbins?) but I was thrilled to get 50+ huge mangos after what birds and/or possums damaged or what fell to the ground & split. I pruned it heavily in Oct. & haven't yet fertilized or sprayed since summer. Last 10 days the pannicles have been shooting out like crazy. The only water it gets is overflow from the birdbath and rain. Hoping against hope for 2 good years in a row! :)

Thanks all. I fertilized and it is fruiting wonderfully. Much fruit drop but plenty left over so far. I find that on very windy days it drops healthy fruit that are too small to ripen. Praying to the wind Gods.