Iowa Ecotype Project / Natural Selections seed is developed from remnant prairie accessions
We divide the state into three Iowa eco-zones based on latitude. Differences in temperature and growing season length from north to south are likely to affect the timing (phenology) of plant growth and reproduction as well as their relationships with pollinators.
To create an Iowa Ecotype, the parent seed is collected from several (preferably >10) remnant prairies within a zone in order to maximize genetic diversity.
Seed sourcing and transfer zones are topics of continuing discussion in the restoration community. See for example: Bower, et al. 2014. Generalized provisional seed zones for native plants. Ecological Adaptations 24(5), pp. 913-919
Increasing seed in TPC production plots
For most species, we start seedlings from parent (remnant) seed in the greenhouse. We maintain records of seed treatments, germination, and challenges encountered in producing transplants.
Seedlings (plugs) are transplanted into production plots in spring and managed with weeding, irrigation (if needed), monitoring of pests, and mowing between plots.
Our production fields are inspected annually by the Iowa Crop Improvement Association as part of their Yellow Tag program for source-identified native seed.
Peak seed harvest for most prairie species is from mid-September through mid-October. Depending on the species, yield, and uniformity of seed ripening, we harvest seed by hand or using our Zürn research plot combine.
Seed conditioning and storage
We condition seed using seed cleaning equipment to remove weed seed and other impurities. Equipment in our seed laboratory includes lab-scale:
- Brush machine
- Air-screen cleaner
- Indent cylinder
- Belt grader
- Spiral separator
- Velvet roller mill
Conditioned seed is packaged and stored under cool/dry conditions in a walk-in cooler to preserve longevity.
We maintain records on all seed lots, allowing tracing to their parent source in remnant prairies.
Remnant (parent) seed collections are cataloged and stored separately in a deep freeze for even greater longevity.