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Seed storage of several New Zealand indigenous trees. Part I - kauri (Agathis australis).
| Content Provider | Semantic Scholar |
|---|---|
| Author | Preest, David Stanley |
| Copyright Year | 1979 |
| Abstract | The viability of kauri seed is ephemeral under ambient conditions. Since collection is difficult, hazardous, and therefore expensive, a satisfactory method of storing seed surplus to requirements would be valuable. Kauri seed was stored in air-tight containers for up to 11.7 years at moisture contents of 6%, 10%, 15%, and 20% oven-dry weight and at constant temperatures of —10°, 5°, 10°, 15° and 20°C. Seed longevity was heavily dependent on both these factors, though moisture content was the more critical. The optimum moisture content appeared to be around 6%. For shortto medium-term storage (up to 6 years) the optimum temperature was about 5°C. For longer storage or higher moisture content (10%) the results suggested that the optimum temperature was below freezing point. This experiment showed that kauri seed can be kept for 5-6 years with viability little impaired, and probably in excess of 12 years with fair viability retained, if stored air-tight under conditions of low moisture content and temperature. INTRODUCTION Kauri (Agathis australis Hort, ex Lindi.) has an abiding fascination for New Zealanders. Persistent attempts spanning 40-50 years have been made to propagate the species artificially by raising seedlings in nurseries and planting them out. Nursery propagation from seed has always proved feasible: to a large extent this has been due to abundant, and regular seed crops, the ease with which the fresh seed germinates, and a reasonably fast rate of juvenile growth. But seed collection is difficult, hazardous, and therefore expensive. It is desirable therefore that seed surplus to requirements one year be able to be stored for sowing in subsequent years. Despite Hutchin's (1918) statement that "there is evidence that kauri seed will lie dormant in the ground for many years . . .", it is well known that kauri seed loses viability quickly under ambient conditions of temperature and relative humidity. Hocking (1935) found that "Stored kauri seed had lost all viability 18 months after collection". McKinnon (1936) noted a 60% drop in the viability of seed stored in a sealed glass jar after 6 months. Sando (1936) states that "The viability of stored seed N.Z. J. For . Sci. 9(3): 337-43 (1979). 338 New Zealand Journal of Forestry Science Vol. 9 is evanescent. In a few weeks it has diminished considerably. . . ." MacMorran's (1946) work indicated that temperature was an important factor. She found that kauri seed stored at room temperature for 2 years had lost all viability, whereas that stored at —9-4° to —12.2°C still retained 64% of its original viability. Mirams (1957) showed that seed stored under conditions of 10% relative humidity (approximately 9% seed moisture content (m.c.)) had a germination of 55% after 12.6 months, compared with approximately 13% after 1.6 months and 0% after 5.3 months for seed stored at 100% relative humidity (seed m.c. approx. 20%). Unfortunately, MacMorran did not specify the seed moisture content and Mirams did not specify the storage temperature. The successful long-term storage of many seeds depends critically upon seed moisture content, storage temperature, and the gaseous environment, especially the exclusion of oxygen (Roberts, 1972). The purpose of this experiment was to determine the influence of seed moisture content and storage temperature on kauri seed longevity under airtight (anaerobic) storage conditions. |
| Starting Page | 337 |
| Ending Page | 343 |
| Page Count | 7 |
| File Format | PDF HTM / HTML |
| Volume Number | 9 |
| Alternate Webpage(s) | http://www.scionresearch.com/__data/assets/pdf_file/0005/36914/NZJFS931979PREEST337_343.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
