Kinetin improves lettuce germination

Freshly harvested lettuce seeds often fail to germinate under favorable temperature and moisture conditions-a failure called post-harvest or after-ripening dormancy. In most varieties, such dormancy decreases during storage; storage time needed depends on variety, percentage of moisture in seeds, field temperature at seed maturation, and possibly other factors. Post-harvest dormancy can be largely overcome by pre-chilling moist seeds for five days at 12° C.