Hybrids? + Hybrid % in a given Seed Orchards may vary substantially from year to year FP 205 FP 244 FP 203
Zygotic selection Whats happends after sowing? During germination Growth in the nursery Culling in the nursery before selling Growth in the Forests after planting
Germin. Interval Hybrid seed Selfed seed Hybrid % (0.06) (0.08) (0.08) (0.17) (0.00) Total (0.05) Zygotic selection - germination time Hybrid fraction according to germination interval FP205 (2004): Hybrid= 63%
Hybrid percent Depends on the sampled germination window … - What is a suitable time window?
Zygotic selection – In the Nursery upto Seedlings 11% -> 11% Bare roots Plug+1
32% -> 45% Bare roots Zygotic selection – In the Nursery upto Seedlings
Hybrid percent Depends on the applied nursery grading E.g. from 70% – 11% -What is a suitable culling regime? -Should all nurseries test before selling?
Zygotic selection – In the Forest after 18 years
Conclusion? Important to know what’s going on in the CSOs Test every seedlot Need for minimum acceptable Hybrid% ? Need for minimum acceptable culling? Production technique?
Involved staff Lars Nørgaard Hansen, UoC Erik Dahl Kjær, UoC Viggo Jensen, UoC Lotte Hougs, The Danish Plant Directorate Henrik Gade Knudsen, Thanks to The Danish Forest and Nature Agency for financial support