Popis: |
SUMMARY Seed characteristics and germinability of Casuarina cunninghamiana, C. glauca and their natural hybrid were tested in lots collected in the autumn and spring from different levels on individual tree crowns. The number of seeds per cone was less for Casuarina cunninghamiana than for C. glauca and the hybrid, which were nearly equivalent in number. Seed collected in the spring had a higher moisture content and lower weight than seed collected in the autumn. Percentage germination varied with species, time of collection and the tree crown level from which seeds were obtained. Generally, percentage germination was higher for seeds collected in the autumn than in the spring, although seed collected in the spring required fewer days for germination because of the warmer conditions at that time. On balance, however, to ensure the highest possible percentage germination, it is recommended that seeds of Casuarina spp. be collected in the autumn, and from the lower portion of the crown of C. glauca, the upp... |