My Mango tree produced no fruit this year. The tree is about 12 years old and we've lived on the property 5 years. In spite of hurricanes (3), I've had many mangoes every year except this year. It didn't even flower, hence no fruit :(
Aren't they insect pollinated? They flower in cold weather here, so are at best hit and miss. Some re-bloom if the spikes freeze. You might spread some organic sources of phosphorus and potash under the canopy around the holidays. (no nitrogen at that time!)
You can also spray copper sulfate on the foliage. Some mangoes develop scab; other types are resistant. You'd have to consult a book for that info.
Makes me wonder what's in the spray we used to use for tomato blossom set!
I believe they might be bi-yearly. or something. Fikkle, anyway. I hope the BIRDS leave me a few...
Funny little quarter inch flies or bees or something buzzing the flowers early mornings. Trees blooming sporadically, nearly full sized fruits all the way to new flowers on the same tree, not only mine.