Oranges

[northwichvics]

Some 5/6 years ago I bought a navel orange tree, this year, for the first time it has fruited, the problem is that  the fruit, 25 ish, have all turned orange already and are small with pronounced splits in them. I am assuming this could be down to lack of water, it has been watered infrequently. Any ideas?
I have just noticed the remarks about Mandarins which probably answers my query. My neighbour, Olly seems to have summed it up well.