A number of protective measures have been implemented, including site access restrictions, the collection and cold-storage of seed, and the treatment of plants with phosphite. Phosphite boosts the resistance of both infected and uninfected plants, and also acts as a direct fungicide. Aerial spraying of phosphite boosts plant survival and slows the spread of infection, but must be carefully managed as studies have shown that foliar spraying of phosphite adversely affects root and shoot growth. Direct injection of phosphite into the stem of each tree appears to lack this disadvantage, but is costly to administer and restricted to known plants.