Improving Conservation through Cultivation: Nine Container Substrates Influence Growth of a Rare Cycad, Zamia pumila L
| Autor: | Kimberly A. Moore, M. Patrick Griffith, Chad Husby, Vickie Murphy |
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| Rok vydání: | 2013 |
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| Zdroj: | HortScience. 48:1168-1172 |
| ISSN: | 2327-9834 0018-5345 |
| DOI: | 10.21273/hortsci.48.9.1168 |
| Popis: | Cycads comprise the most threatened major group of plants on earth and many species require horticultural assistance to ensure their survival. Appropriate container substrate properties, especially relatively high air space content, are crucial to successful cultivation of most cycads from seed. Cycad substrates in common use include substantial portions of organic materials that will decompose over time, reducing aeration. At Montgomery Botanical Center, novel inorganic substrates have improved survival and growth of several very rare and challenging Zamia species, suggesting the need for a rigorous evaluation of different inorganic container substrates. Effects of 1) coarse silica sand (6/20 grade); 2) Fafard (a peat/perlite mix); 3) perlite (expanded volcanic glass); 4) pumice (volcanic rock); 5) Turface (calcined clay); 6) Profile (calcined clay); 7) a 50% sand (6/20): 50% Profile mix; 8) Permatil (calcined slate); or 9) Axis (calcined diatomaceous earth) on growth of Zamia pumila L. seedlings (grown from seed of Dominican Republic provenance) were evaluated. Growth parameters were measured after 18 months. Sand produced significantly higher total dry weight and leaf area than all other substrates. A combination of at least 18% air space combined with little coarse material (sand) or with some coarse material combined with enough smaller particles to fill part of the large pores created by coarse material (Fafard) likely contributed to better growth in these compared with the other seven substrates. The other substrates may have been either too coarse, leading to excessively large pores, which are known to inhibit growth in some plants if the pores are much larger than fine root diameters, or too fine (i.e., too low of an air space percentage). The fine roots of Zamia can be less than 1 mm in diameter, whereas higher proportions of coarse substrate particles over 4 mm in diameter inhibited growth, possibly by creating excessively large pores. In contrast, higher proportions of fine substrate particles of 0.25 to 0.5 mm were beneficial to growth. |
| Databáze: | OpenAIRE |
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