Ammonium salt of fosamine (fosamine) is an organophosphate pesticide used to control woody and leafy plants, such as maple, birch, alder, blackberry, vine maple, ash, and oak. Fosamine is a selective, postemergent (after growth begins) herbicide that prevents dormant plant tissues from growing. Fosamine herbicidesare used primarily in the control of brush and small undesirable trees. Fosamine also has industrial and forestry uses.