Effect of seed size and substrate on germination of Eucalyptus citriodora Hook

Abstract

In an experiment to determine the influence of substrate and seed size of Eucalyptus citriodora Hock on germination, seeds were divided into 3 size classes: 1) greater than 3 mm, 2) 2-3 mm, and 3) less than 2 mm. Germination tests, using 4 samples of 25 seeds from each size class, were conducted in a controlled environment chamber. Germination was done in Petri dishes using two media on filter paper and in sterilized soil. The experimental design was unrestrictedly randomized, in a 2 x 3 factorial arrangement. The results indicated that larger seeds germinated better and faster. Since the germination percentage and germinative power of seeds sown in the soil did not differ from that of seeds exposed to light (on filter paper), direct light is apparently not required for germination of E. citriodora seeds. It is suggested that complementary experiments be carried out to determine the influence of seed size on the quality of seedlings of this eucalyptus species.