Influence of harvest time and storage location on the longevity of timothy (Phleum pratense L.) seed

Abstract Norwegian agriculture relies heavily on a safe supply of seed of winter-hardy timothy cultivars. To buffer variations in seed consumption and seed yields, seed companies keep stocks corresponding to 50–100% of average annual seed consumption. Such large stocks are risky to maintain as seeds lose germination over time. Our objective was to elucidate the effect of seed harvest time and seed storage location on the longevity of timothy seed. In 2003, the Norwegian timothy cultivars, ‘Grindstad’, ‘Vega’ and ‘Noreng’, were combined directly at three different seed harvest times corresponding to a seed moisture content (SMC) of 33–35% (H1), 26–28% (H2) and 16–20% (H3), respectively. Germination analyses were conducted before storage and after 12, 24, 36, 48 and 60 months of storage in a conditioned seed store at Landvik (4°C, 30% RH) or in unconditioned warehouses at three climatically different locations (Tynset, Holstad and Vaksdal). Seed harvest time became increasingly significant as time went by. ...