Effect of seed aging on the seed quality and seedling growth of timothy grass (Phleum pratense L.)

Abstract

Timothy grass is a fodder grass mostly grown as a pure stand or in mixed stands with fodder legumes at higher elevations. It is cultivated for its high yields and the supreme quality of roughage containing Timothy grass. There are different methods for preserving the seed quality of fodder grasses relative to the following parameters: species, variety, harvest methods, postharvest treatments, as well as the storage temperature and air humidity. Poor seed germination is often caused by the presence of dormant seeds which fail to germinate despite ideal conditions in the field or laboratory. After a certain storage period, dormant seeds start germinating, but prolonged storage periods result in seed aging which is associated with reductions in seed germination, seedling growth and the total mass of the root system. The seed quality features of four Timothy grass seed lots (the 'Foka' cultivar), at ages of 3, 15 and 27 months, were examined in this study according to the share of dormant, germinated and dead seeds, as well as abnormal seedlings. Upon assessing seed germination, the stem length (cm), radicle length (cm) and fresh weight (g) of seedlings were measured. Different seed lots were found to exert no effect on the seed quality parameters examined and the growth of seedlings. Conversely, the seed age had a significant impact (P <0.001 to P <0.05) on the seed quality parameters examined and the seedling growth.