1957 Volume 26 Issue 1 Pages 28-32
Dormancy of perilla (Perilla ocymoides L. var. crispa BENTH.) seed was studied.
1. Dormany of perilla seed continues for about three to five months after harvest, and it is very deep for the first month after harvest.
2. Germination of perilla seed is light-favored. In some cases, however, it is dark-favored for some period after harvest, and turns to light-favored thereafter. Causes of this variability in photosensitivity are not known yet. The grade of photosensitivity does not vary after dormancy has disappeared.
3. Causes of dormancy of perilla seed exist mainly in seed coat and partially in embryo.
4. Effective dormancy breaking treatments are decoating, sulfuric acid treatment and prechilling. Prechilling is most useful in practice.
5. Perilla seed aquires germinating ability in high temperature through aging or prechilling.
6. Dry seeds in normal air-humidity, as well as wet ones, are affected by light condition. Germination percentage in darkness is higher when the seeds have been kept under light than when kept in darkness.
7. Germination rate of perilla seeds is low when sown in soil. The rate increases considerably when the seeds have been presoaked under light for about one day.