My orange tree (3 yrs old) had a lot of "set fruit" and then little orange by little orange they fell off.

Question:I only have 2 oranges that look like they are going to stay on for the long haul. What causes set fruit to just drop off? What might I be doing or not doing to cause this?

Answers:
Depending on the season where you are it may have been frost if they are very small, or the most likely reason is the tree doesn't think it can support the fruit probably due to lack of water, and has thrown them off.

Citrus like full sun, regular water, and are gross feeders so lots of aged manures or citrus food. Make sure it doesn't dry out next year after it has set fruit, and you should be right.