Fungicides are crop-protection chemicals that kill or suppress pathogenic fungi on growing crops and harvested produce, protecting yields and reducing mycotoxin contamination in cereals, fruits and vegetables. They are applied as sprays, seed treatments or postharvest dips, with timing chosen to protect the crop through its vulnerable stages. Because residues may persist to the consumer, regulators establish maximum residue limits and growers must observe pre-harvest intervals; postharvest fungicide treatments are additionally regulated as food treatments. Resistance management through rotation of modes of action keeps these tools effective, and residue monitoring programmes verify compliance in traded produce.