The full chemical name of the herbicide 2,4-D, a synthetic auxin that throws broadleaf plants into fatal, disorganised growth. Farmers depend on it for post-emergence weed control in cereal crops, pastures, orchards and sugar cane, valuing its selectivity for grasses. The World Health Organization classifies it as moderately hazardous. Residue questions follow it into the food chain: harvested grain, fruit and vegetables from treated fields are subject to maximum limits, and monitoring programmes test for it routinely. Its long history also makes it a reference point in discussions of herbicide resistance, drift damage and water contamination.