ENTRUST 18SL is a herbicide formulation containing 18 % glufosinate-ammonium as its active ingredient, not glyphosate-potassium. Glufosinate-ammonium is a non-selective, systemic herbicide effective against a broad spectrum of weeds. It works by inhibiting the enzyme glutamine synthetase, leading to the accumulation of toxic levels of ammonia in plant tissues, resulting in plant death.