Comparative studies on the germination of Scots pine and Norway spruce seed under different temperatures and photoperiods
Kamra, Siri Krishan
1. The present paper deals with a comparison of the percentages and the rates of germination of samples of Scots pine and Norway spruce seed under different sets of temperatures and photoperiods. Ten samples each of Pinus silvestris L. and Picea abies (L.) Karst., some with high, others with lower germination percentages were taken for the experiments. The details of the material are given in Tables 1 and 2. 2. Four sets of germination conditions: three with 8 hours light daily and alternating temperature of 20-30°C and constant temperatures of 23°C and 20°C, and one with 24 hours light daily and 20°C were used. For further details of the sets, see the Methods. 3. There were no statistically significant differences among the germination percentages of the samples of Scots pine and Norway spruce seed under the four sets of conditions (cf. Tables 3 and 4). 4. The germination rates of severa1 samples appeared to be faster during the first few days of the tests at the alternating than at the constant temperatures under similar light conditions. However, from a certain point onward, which was different in the different cases, there were only small differences in the germination rates of the samples (cf. Figs. 1-20). Judging by all the samples and by the whole periods of the tests, the germination rate was not necessarily faster at the alternating than at the constant temperatures. 5. The germination tests under 8 and 24 hours light daily at 20°C did not show any consistent difference in both the species in the rate of germination, and practically no difference in the percentage of germination, under the two photoperiods. 6. The investigation has thus shown, that any of the four sets of conditions (I-IV) can be used for testing the germination percentage of Scots pine and Norway spruce seed.
germination; Scots pine; Norway spruce; seeds; temperatures; photoperiods
Studia Forestalia Suecica
Permanent link to this page (URI)