Diagnosing poor quality seeds in cereals
Poor grain quality can impact on germination rates and market quality. It can be caused by harvest, storage and the weather or environment.
What to look for
- Reduced germination and/or weak seedlings that are uniformly affected across a paddock, or more pronounced in rows or other areas that are deeper sown.
Paddock
- Seeds swell but fail to germinate.
- Seed germinates but seedlings are malformed or too weak to to reach the surface. Weak seedlings after emergence.
- Reduced wheat or barley coleoptile length.
- Broadleaf seedlings with broken roots, cotyledons or growing points.
Plant
Where did it come from?
Wet conditions
Temperature
- Grain quality can be affected by the following defects:
- Sprouted grain - This can occur after prolonged periods of wet weather when the wheat grains have matured and while they are still on the stem before harvest. Grains are considered sprouted when the covering of the germ is split open and includes more advanced stages of growth.
- Dark fungal staining produces a dark brown, black or grey discolouration on any part of the grain and is often associated with shrivelling. This form of discolouration is caused by fungal disease occurring in the grain. Occurs with wet, humid weather during grain maturity.
- Black point - This is where the germ end and creases of the kernel turns brown/black and is not to be confused with fungal staining. It has no effect on seed viability.
- Mouldy grain - Weathered or mouldy grain occurs when grain receives rainfall or very high humidity after maturity causing growth of the natural saprophytic fungi resulting in a mouldy discoloured appearance. Mouldy grain can occur in the field or during storage, especially if grain moisture content is too high.
- Frost-affected grain.
- Green sappy grain that has been harvested too early.
- Grain affected by diseases such as fusarium head blight. Seed treatments that have reduced grain vigour or viability.
- Insect damaged grain.
How can it be monitored?
- Germination test grain being retained for seed.
Where to go for expert help
Page last updated: Friday, 17 April 2015 - 2:04pm