Influence of seed storage conditions on seedling emergence, seedling growth and dry matter production of temperate forage grasses

An experiment was initiated in 1984 to compare the effectiveness of the new controlled environment seed store at the Institute of Grassland and Environmental Research (IGER), which has control of temperature and humidity with a conventional fridge store which has no control of humidity. Seed of perennial ryegrass (Lolium perenne L.), Italian ryegrass (L. multiflorum Lam.) and hybrid ryegrass (L. boucheanum Kunth.) was stored in sealed jars, linen and plastic bags and placed in each of the storage environments. In 1996, after 12 years storage, all seed lots were sampled and seedling emergence, date of emergence of first tiller and seedling dry weight measured in soil trays in a glasshouse. Rate of emergence and numbers of emerged seedlings were lower from the fridge than the seedstore. In the fridge, the linen bag was the least effective storage method. However there was no significant effect of storage on seedling dry weight. In spring 1998, seedling emergence and dry matter production of the seed lots were compared in a field experiment at IGER. Many of the differences in emergence observed in the glasshouse were also observed in the field. Some initial differences in dry matter production were observed but these were not significant at later harvests. The basis for the decline in seedling emergence and implications for forage production are discussed.