Covered smut (oats)

Covered smut in oats is very similar to covered smut in barley. It is only evident when the heads emerge. Instead of seeds, heads contain black spore masses enclosed in a seed coat.

Life cycle

Covered smut spores are carried on the outside of the seed and can remain viable for up to three years. When infected seed begins to germinate, the spores also germinate and penetrate the shoot of the seedling just before emergence.

The fungus then grows in between the plant cells just behind the growing point of the plant. Plants become resistant to covered smut infection after emergence and therefore, if an uninfected plant has emerged, it cannot become infected. The fungus enters the tissues of the head, once formed, and b lack spore masses are produced in the head instead of normal grain.

Covered smut infection is spread during harvest and other seed handling operations, when infected grains are mechanically broken and spread amongst healthy grain.

Control

• Treat the seed with a recommended seed treatment (Foliarflo-C, Vitaflo C, Vitavax 200FF, Rancona C, Rancona Dimension)
• Sow disease free seed