cheeko trees

[khawajaumerilyas]

AOA Every one
I have planted two cheeko trees at my home in lahore about a year back,they are about 3.5 feet of height.Last year they also had a few fruits on them and this year again they have fruits but the fruit fall down even when it is of size of small grains,i spared it with imported fertilizer, i added npk and later dap in soil around it but result is still hopeless,my question is,is my plants suffering from any disease or yet they are young for proper fruiting.One thing i use to give water them after ten days once flower appears on it.
Thank you
Umer