C/O: ustilago nuda tritici

Symptoms:

• Appear only after emergence of the ears.
• Every ear of the affected plants is converted into a black mass of spores and no grains are formed.
• The infected heads emerge from the boot leaf one to three days earlier than those of healthy plants.
• All parts of the spikelets convert into smut spores except awn.
• Initially smut sori, covered with thin silvery membrane.
• Later, at emergence, the membrane breaks and spores liberated in atmosphere.
• All of the floral parts of the head, except for the rachis and pericarp membrane, are invaded by mycelium of the fungus and converted into loose aggregates of smut spores (teliospores)