There is nothing you can do that will guarantee that your trees won’t be infected by a citrus disease but there are some things you can do that will lower the risk.  First, check with your local county extension agent or the Alabama Cooperative Extension Service website (www.aces.edu) for tips and information about growing citrus. Secondly, avoid overhead irrigation by using drip irrigation instead. Next, clean your tool regularly to avoid cross contamination and inspect your trees regularly for any signs of disease.  With early detection, you may be able to prune your trees to remove infected branches.  Do not use the cuttings in compost or put out as trash but bag the cuttings and call ADAI to report the discovery so they can test the suspect plant for disease.  The proper application of fungicides and pesticides can be a preventative. Ask your garden Center or Cooperative Extension agent for those recommendations.