Birdsfoot Trefoil Seed Production
Introduction
Birdsfoot trefoil seed has a strong market demand, but successful production requires careful management and adaptation to local conditions. Production involves three phases:
- Pre-establishment period
- Establishment year
- Subsequent production years
Pre-Establishment Year
Site Selection
- Choose fields free of quackgrass, clover, and other perennial weeds.
- Prefer clay or loam soils with good water-holding capacity.
- For pedigreed seed, follow Canadian Seed Growers’ Association for isolation requirements.
Site Preparation
- Eliminate perennial weeds (quackgrass, Canada Thistle, sowthistle and dandelions) before seeding; control is costly after establishment.
- Conduct a soil test to determine fertilizer requirements for the establishment year.
Establishment Year
Fertilization
- Apply phosphate, potassium, and sulphur as per soil test recommendations.
- Broadcast fertilizer prior to seeding; avoid application on frozen soils.
General Fertilizer Guidelines:
Stand Type |
P₂O₅ |
K₂O |
S |
New Stands |
54–76 lb/ac |
58–152 lb/ac |
27 lb/ac |
Established Stands |
40–54 lb/ac |
40–98 lb/ac |
27 lb/ac |
(Metric equivalents: P₂O₅: 60–85 kg/ha; K₂O: 65–170 kg/ha; S: 30 kg/ha)
Weed Control
- Pre-plant:
- Eptam for grass and broadleaf weeds (no companion crop).
- Avadex BW for wild oats when seeding with barley, wheat, flax, or canola.
- Post-emergent:
- 2,4-DB for broadleaf weeds in seeding year.
- Princep Nine-T, Simazine 80W, or Kerb for established stands.
- Refer to Guide to Crop Protection for current recommendations.
Inoculation
- Use birdsfoot trefoil-specific inoculum; apply twice the normal rate for first-time sowing.
- Preferred methods:
- Slurry: Mix inoculum with water and coat seed evenly.
- Adhesive solution: Add corn syrup (2 tbsp per quart water) for better adhesion.
- Avoid dry application; pre-inoculated seed is an option if properly stored. If using dry inoculum use 2-3 times the normal rate.
Seeding
- If EPTC is applied, seed without a companion crop.
- If using a companion crop, choose a low-competition species like flax.
- Seeding rate: 1–2 lb/ac (1–2 kg/ha).
Production Years
Roguing
Remove undesirable weeds (e.g., sweet clover) to maintain seed purity.
Pollination
- Ensure adequate bee populations for pollination.
- Recommended: 1–2 colonies per acre (2–5 hives per hectare).
- Wild pollinators are effective near bushland; otherwise, arrange hives with local beekeepers.
Harvesting
- Harvest when ⅔–¾ of pods are brown, before excessive shattering.
- Best method: Swath slightly damp to reduce shatter, then combine after 2–5 days.
- Expect challenges in separation due to small, light seeds—clean further at seed plant.
Additional Information
Consult seed trade companies for marketing opportunities and production advice.