Looks like iron or magnesium deficiency - which could be caused by either drought or too wet of conditions.

Thanks. Sorry for the late reply, I never received a follow up email and have problems finding my old posts!!

I'm thinking it's too dry . . . when we bought the property the irrigation had not been run in over a year! Good to know, we will start irrigating.

Would horse manure work well as a mulch for this type of tree?

your lychees and macadamia nut trees would both probably benefit from an annual chelated iron drench.

not cheap but our soil lacks Fe and chlorosis is the usual result.

Katie from Going Bananas told me about this, their lychee grove thrives and i am currently following their model.

it looks like you are sitting on a beautiful piece of property, make sure you post up alot of pics (if you need help how to do that let me know)

this is where you want to post if youre looking for tropical fruit tree and variety identification.

and if you ever need a grove hand to harvest fruit, i am free weekends and will work for lychees.

Thanks mango_kush.....I'll have to look into the chelated iron drench. Sounds $$$$ :)