Effect of storage temperature and duration on the vigor of zoysiagrass (Zoysia japonica Steud.) seed harvested at different maturity stages

Abstract

Zoysiagrass (Zoysia japonica Steud.) is one of the most important warm season grasses used as forage and ground cover in eastern Asia. This study was conducted to evaluate the effects of temperature and duration of storage on germination and conductivity in zoysiagrass seeds. The seeds were harvested at the milk, dough and hard stages, and stored at a low (7°C) or an ambient (15-30°C) temperature for 6-18 months in sealed polyethylene bags. The standard germination rate of seeds decreased significantly (P < 0.05) as the storage period prolonged from 6 to 18 months. Germination was almost always better in seeds stored at the low temperature than at the ambient temperature and highest in seeds harvested at the hard stage followed by the dough and the milk stage. Following accelerated aging, germination was highest when harvested at the hard stage and stored for 12 months. Bulk conductivity was lower in seeds stored for 6 and 12 months than those stored for 18 months and in seeds harvested at the hard stage than those harvested at the dough and the milk stage. The results indicated that zoysiagrass seed maintained a higher vigor level when harvested at the hard stage and stored at low temperature (7°C) for 12 months or less. © Journal Compilation © 2009 Japanese Society of Grassland Science.