Why lychee drops fruits?

[Tony714]

Hi guys,

I have grafted lychee on longan tree.  Its over a year old and first time fruit.  At first, i fertilized it but I heard it's sensitive so havent fertilized it since last winter.  Does anyone have any idea why it drops fruits.  Let me know how you take your tree.
Thanks
Tony

[spaugh]

The tree is too small to hold fruit.

[Tony714]

Scion came from 5 years old tree.  How old is it able to hold fruits?

[spaugh]

The scion wood can flower and set fruit but look at the size of the tree.  Theres no canopy to support fruit.  You would be better off letting it size up more and not spend energy on fruiting for several years. 

This is not directed at you.  Just a general comment and its been said many times here already.  Growing fruit trees isnt a race.  It takes time and usually makes sense to let trees get some size before letting them fruit.  Especially things that lack vigor in our climate like lychee and mango.

[Guanabanus]

I agree with Spaugh's point.

There may also be a couple of other things to consider:
I noticed that all the drops are paired/divided.  Are the fruits that stayed on the tree like that?

When the soil gets too dry, even for just one afternoon, the dropping of fruit can be activated.

Low Boron and low Calcium can also cause fruit drop.

Too much fertilizer can also cause fruit drop, usually in conjunction with soil dryness.

[Tony714]

Its great inputs.

Thank you Brad and Har