I think you should consult with your local extension service about this. They will have some good information for you that should be regionally pertinent.

Here is one link : http://edis.ifas.ufl.edu/CG009

Foot rot results from infection of the scion near the ground level, producing bark lesions which extend down to the budunion on resistant rootstocks. Crown rot results from infection of the bark below the soil line when susceptible rootstocks are used. Root rot occurs when the cortex of fibrous roots is infected, turns soft and appears water-soaked. Fibrous roots slough their cortex leaving only white thread-like stele. Foot rot and root rot can be caused by P. nicotianae or P. palmivora. When managing Phytophthora-induced diseases, consider integration of cultural practices (e.g., disease exclusion through use of Phytophthora-free planting stock, resistant rootstocks, proper irrigation practices) and chemical control methods. Phytophthora management with chemical control should not be considered until other potential causes of decline in tree production are evaluated and corrected.

Sounds like a tough disease to control or cure !

Thanks for the information. I stopped by the local nursery they said not much I could do but stop watering. Water only once every 3-4 weeks!!
I also go a copper spray. I removed the gum looking substances around the trunk and sprayed the trunk with the copper liquid.
Not sure what else to do but keep my fingers crossed.
Here is the other thing - I was planning on putting in grass seed in the yard around the oranges. Was looking to put in sprinklers - Gees what the heck do I do. People must have grass with oranges in the same yard?

Thanks again

I had some footrot on my mandarine tree when I let the grass grow around the base of my trees. It looked pretty bad on a three year old tree (about halfway around the base). Without weed whacking, the grass was rather thick right at the base of tree. I removed the grass from the base, sprayed with copper, stopped watering, and now spray weed killer under the trees. It has not come back in two years. My trees are planted in the ground.

In addition to all the good information above, foot rot often happens on a tree that was originally planted too deeply. If feasible, you might consider (gently) excavating soil from around the trunk, until the first root or two are visible above ground. then just keep that area open to the air. Ridomil Gold and/or Aliette fungicides will almost immediately halt the disease and allow healing (RG is a soil drench, and Aliette is a foliar spray), but they are pricey and you can't buy a small quantity. Also, while they give an immediate cure, unless you can change the environmental conditions that made the tree susceptible in the first place, it will come back as soon as the weather is right and the fungicides have worn off.

THANKS!! I will try one of the products. Aliette a 5lb bag is available for $95. Ridomil Gold 1 pint is available for $130 .

Would you know of exact instructions (a web site) on how to use both these products?
Which one do you think is more effective?
Also will this poison the fruit on the tree? Is it safe to eat?

Thanks again.

Both are quite effective. Just follow the instructions on the label, which will also tell how many days prior to harvest you can use them. You could download a label from the internet before buying, to be sure.

The Aliette label is available at http://strawberry.ifas.ufl.edu/plantpathfiles/TS%20fung%20label%202006/aliette.pdf

It is labeled for use no less than 30 days before harvest.

The label for Ridomil Gold SL is at:
http://www.syngentacropprotection.com/asp/redirectlblDownload.aspx?lblposition=1&ProdID=952&ProdNM=

It does not seem to indicate any waiting time before harvest (unless I'm just not spotting it).