Diagnosing seedbed constraints in narrow-leafed lupins and field peas
Seedbed problems include poor seed-soil contact, poor depth of seeding, and soil crusting.
What to look for
- Uneven germination and stunted plants that often occur along drill rows, heavy stubble areas, or specific soil types.
Paddock
- Reduced and/or staggered germination.
- Smaller or stunted plants.
- Poorly covered seed. Seeds germinating near the surface are more susceptible to fungal root rot.
- Hairpinned stubble or other organic matter may be close to the seed.
- Surface crusting can cause damage to seedling cotyledons and growing point
Plant
What else could it be
Condition | Similarities | Differences |
---|---|---|
Diagnosing water repellence | Reduced and staggered germination | Restricted to water repellent areas and the problem is ongoing. |
Diagnosing poor quality seed in narrow-leafed lupins | Reduced and staggered germination | The problem is more likely to be evenly distributed throughout the paddock; malformed seedlings. |
Diagnosing allelopathy in narrow-leafed lupins | Reduced and staggered germination | Allellopathic affected plants remain pale, distorted and stunted and may be caused by toxins leaching into the seedbed or from contaminated seed. |
Diagnosing waterlogging in narrow-leafed lupins and field peas | Reduced and staggered germination | Restricted to water gaining areas and the problem is ongoing. |
Diagnosing salinity in narrow-leafed lupins | Reduced and staggered germination | Restricted to water gaining areas and the problem is ongoing. |
Where did it come from?
Air around the sown seed prevents it from absorbing moisture from the soil. Examples include:
- Seed sown on the soil surface.
- 'Hairpinning', where straw is pinned in the seeding slot, leaving air voids and increasing the risk of allelopathy.
- Poor seed-soil contact from insufficient soil firming or poor coverage of the seed in the seeding slot.
Management strategies
- To ensure sufficient seed-soil contact it is important the sowing machinery is designed to seed at a uniform depth and provides uniform soil cover.
- Systems such as harrows and prickle chains are subject to variation in the soil surface. Press wheels offer increased control.
Where to go for expert help
Page last updated: Wednesday, 6 May 2015 - 11:17am