Influence of different storage conditions on quality characteristics of seed material from semi-natural grassland

Neither methodology nor guidelines are available for defining quality characteristics and storage conditions of seed material harvested from semi-natural grassland. Seeds from an Arrhenatherion meadow were harvested via on-site threshing and seed stripping. After determination of purity, thousand seed weight and pre-tests in a phytotron, germination-capacity trials were carried out in a greenhouse. The harvested seed material was stored for up to 3 years under different conditions: (i) room temperature 18–23°C, (ii) cooling chamber (2–5°C with 40–50% humidity) and (iii) freezer (−18°C). There was a significant impact of the tested harvesting methods on seed separation, thousand seed weight and purity, but not on the germination capacity. Different storage conditions and storage length significantly influenced the germination capacity. There were also generally higher germination values for the seed-stripping material than the on-site threshing material (ca. 70 and 60%, respectively, in the first year). Germination capacity decreased significantly with time and was <15% after 3 years. We conclude that harvested seed material from semi-natural grassland should preferably be stored under cool conditions and used within 2 years.