False loose smut

Smutted head emerges through the sheath below the boot leaf. At head emergence, infected heads are covered by a delicate greyish membrane, under which is hidden a dark brown or black powdery mass of spores. Spores are blown or washed away, leaving an inconspicuous bare rachis. Disease overwinters on seed surface. Under favourable conditions, seed-borne spores may germinate and produce mycelium under kernel hulls. Both mycelium and spores remain dormant until germination when fungus grows and penetrates seedlings. Growth continues undetected until heads develop. By head emergence, heads contain smut spores instead of seed and chaff.

Scouting

Look for abnormal head emergence through the sheath below the boot leaf. Scout at heading for delicate membrane over emerging heads. After heading, look for unusual tightly-compacted heads and deformed awns or only a remaining rachis.

Control

Resistant cultivars have been developed. Use smut-free seed.