Kent Mango

Hi,

I am staying in South Africa. I have a Kent Mango tree and it is now six years old. It had a good crop this year, but all my mangoes is small! They don't measure more than 10 cm (4 inches). Our summers is hot - 38 degrees C (100F). I water the tree once a week heavily (I've got a basin around the tree which I fill up). I give fertilizer every month from the blooming stage. I don't prune the tree. The tree seems healthy. Why don't I get huge mangoes?

Trees sometimes produce more fruit than they can bring to full-size, so you have to "thin" the fruit to get the fruit to reach full size. Thinning fruit simply means picking off some of the fruit on each branch early in the season, so the rest of the fruit can receive more resources from the tree and reach larger sizes.

Imagine this - if every six inches or so of a tree-branch can produce 1 large fruit, but four fruits are growing within that six inches of branch, then the nutrients the branch will provide will be divided between those four fruit and they'll be smaller.

There's a proper balance you want that'll vary from tree to tree, and sometimes trees will on their own "drop" half their crop early on, to thin themselves. Most of the time, you need to thin them. Trees don't always produce so much that they require thinning though - some years they'll produce the right amount on their own. Unfortunately, if they overproduce one year, and aren't thinned, they may produce too little the next year, or even produce nothing, to recover from the overproduction. So don't be shocked if you get zero mangoes next year - this is just because it overproduced this year, and wasn't thinned.

Here's more detailed information from USA's Oregon State University.

Jamin, thanks! I did thin heavily but it still did not produce up to size. There was about 80 mangoes left to mature on my 3 meter high tree. They still didn't came to size. Should I thin more?

So, from mango land here-- while there are plantations, most people here with mangoes in the yard don't bother thinning- it's hard to get up there, most people pick with poles, and it doesn't seem to affect size from what I have seen (I regularly pick trees that get no attention whatsoever, in abandoned areas, and they are packed with fruit and do just fine).
Sometimes water availability can make fruit go from large to extra large or stay a bit smaller, but in general from what I've seen fruit size tends to be a trait for each tree. Here we have more kinds of mangoes than I know the name for, and each has a size range- from tiny coconut mangoes (mostly seed, maybe the size of a ping-pong ball) to huge honking Tommy Palmer mangoes, where I've seen them almost as big as my head, although those were total "hey look at this" anomalies-- a palmer mango is usually about the size of my hand. I don't think I've seen a kent mango outside of books, so I can't speak to that specific one.
My concern would mostly be about actual fruiting (here we tend to lose entire seasons due to sudden weather like a windstorm that blows all the "flowers" away, for example) and then flavor. Your tree seems mature enough at 3 meters and setting out flowers. Maybe it's just a smaller kent. Do they taste good?