Some Factors Influencing the Germination of the Common Hornbeam (Carpinus betulus L.) Seeds

Abstract

Common hornbeam ( Carpinus betulus L.) seeds, in order to be successfully used for forestry and horticulture, need to go through class ical warm-cold stratification in a wet peat-sand substrate to break their dormancy. Hundred seeds s amples of the species were put into stratification using 5 different methods: 1/ check - classical met hod with warm: 4 weeks at 20-22 o C and cold: 16 weeks at 3-5 o C, treatment in a substrate of peat and sand, 2/ a treatment without the substrate but soaking the seeds in water (20-22 o C) for 1 hour every week (warm stage) or every 2 weeks (cold stage), 3/ a treatment without the substrate but mo istening the seeds for 10 seconds into water (20- 22 o C) every week (warm stage) or every 2 weeks (cold stage), 4/ a treatment without the substrate but preliminary soaking the seeds in the 0.1% GA 3 solution for 24 hours at 20-22 o C and then following the moistening procedure described before, 5/ a treatme nt without the substrate done the same way as before but using 0.5% GA 3 solution. In all the treatments, every week in the warm and cold stage of the stratification, the seeds were put on a routine germination test to evaluate their germination capacity. The conducted experiments proved that the common hornbeam seeds could successfully germinate when in the classical warm-cold stratific ation method the peat-sand substrate was replaced by cyclic water soaking or moistening of the seeds. The freshly harvested seeds had germination inhibitors, but their washing away with water neith er shorten their stratification time nor improved t he seeds germination. The used soaking in the 0.5% GA 3 solution did shorten the stratification time of th e seeds. The final germination capacity depended also on the health status of the seeds.