Well, I see by my pin on the map that I am the only member outside the US. We have purchased a house on grounds that were once an avacado plantation. We have many wonderful trees that are full of fruit - and some that aren't and seem to have some type of fungus. We also have 3 fantastic cactus gardens I wished you could all see - but it's the fungus on the avacado trees that has me worried. They have a white 'crystal type growth' on the places where limbs have been cut and then the limbs themselves seems to be covered with a brownish-dust that when you touch it comes off white. I am NOT a gardner. Yes, I once grew very large zuchinni and tomatoes but that's about it. So any suggestions or help would be greatly appreciated!

Re

Welcome to the Garden Helper Re

Since you have a plant problem included in your introduction I am going to move your post to plant pests and problems and we can continue the discussion there.
Catlover

I don't have much time but found a University of California site that may help figure out if your avocado's are suffering from some disease or pest.
Click here! Avocado diseases and insect problems

I know when you cut limbs from avocado's or wound them (for example kids hitting the bark with an object) they will produce a white crystal fungus looking "stuff". Most of the time the tree will heal itself if it was from a cut or wound....at least that is from past experience. I don't know why the branch would be having the fungus.
Take a look and read the info contained in the above link and see if it will help. Take a look at Avocado Black Streak first and see what you think!