Swietenia (macrophylla)
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Kevyn Wightman Tropical Forester and Nursery Specialist Rancho Santa Ana Botanic Garden Carr Sur, km 12.8 Managua, Nicaragua, Rhode Island 505-265-7303 kevyn@ibw.com.ni www.rsabg.org |
| Family Scientific Name: | Meliaceae | ||
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| Family Common Name: | Genuine Mahogany | ||
| Scientific Name: | Swietenia macrophylla King | ||
| Common Name: | Big-Leaf Mahogany; caoba | ||
| Ecotype: | tropical evergreen and tropical deciduous forests | ||
| General Distribution: | Big-leaf mahogany is a fast-growing, mid- successional species generally distributed between 18 N and 18 S latitudes (mid-Mexico to Bolivia) from 0-1500 m elevation in the neotropics. It tolerates a variety of soil types, growing best on fertile, deep soils with a pH between 6.6-7.5. It does not grow well on rocky or waterlogged sites and does not tolerate frost or fires. Optimum natural development occurs in tropical dry forest conditions with an annual precipitation of 1000-2000 mm and mean annual temperature of 24 C. In the natural forest, tree density is very low, often less than 5 individuals of any diameter class per ha. Natural regeneration is dependent on canopy gaps (often caused by natural disturbances such as hurricanes) that allow sufficient light. | ||
| Propagation Goal: | plants | ||
| Propagation Method: | seed | ||
| ProductType: | Container (plug) | ||
| Time To Grow: | 0 | ||
| Target Specifications: | Mexal et al (2000) recommend minimum diameter of 5 mm, while previous authors (during the 1960s, possibly working with bare root plants) recommend 1-2 cm diam. In general, the stem base should be woody. Various studies on the optimum height report sizes from 30-150 cm, however, complete nursery practices were not recorded and hence are site specific. | ||
| Propagule Collection: | S. macrophylla is monoceious with unisexual flowers which are pollinated mostly by bees and moths. Flowering period varies greatly by region. In Mexico, flowering begins in March. After fertilization, fruit requires 9-11 months to mature. Annual fluctuations in flower and fruit production are common. Trees begin producing by age 12, earlier in open areas. Maximum fecundity has been registered in trees 90-130 cm. diameter. Each woody capsule contains 40-60 winged seeds that are wind dispersed. Large differences in capsules and seed size exist; one kg may contain between 1300-2100 seeds. Seeds should be collected while pods are still closed, but brown in color, not green, using extendable pruners, otherwise they are difficult to find and rot quickly on the ground. An unfortunate, but common practice is to scale the trees and cut whole branches with a machete eliminating flowering 5 years or longer. | ||
| Propagule Processing: | Germination is hypogeal and rates are high with fresh seed, 80% on average, but drop greatly when stored under ambient conditions in sealed containers. Nonetheless, seeds are considered orthodox. Seed purity is 95%. By 3-4 months, less than 50% germinate, by 6 months almost none. Farmers have reported that seeds store longer at ambient conditions when the wing is not removed. Seeds have been successfully stored in airtight containers at 4C with 4% humidity for up to 8 years without losing viability. | ||
| Pre-Planting Treatments: | Seeds do not require pre-treatment due to their high germination rates, although some authors recommend soaking seeds 24 hours at ambient temperature to improve germination. Seeds should be dewinged to fit into containers, and some authors recommend sowing the seed horizontally to avoid shoot deformations, although seeds are also commonly sown wing up or down. Sowing depth is shallow; about 1-2 cm. Germination begins 1-2 weeks after sowing. An unfortunate, but common practice is to germinate seeds in beds then `prick out' or transfer seedlings to containers that result in j-rooting of the tap root. Direct sowing in containers is recommend to avoid this problem. | ||
| Growing Area Preparation/ Annual Practices for Perennial Crops: |
In non-industrial nurseries in the tropics, the most common production system is in poly bags (perforated black or clear plastic bags) filled with forest soil. For most forest species, 0.5-0.7 l or 1.5 l bags (6-12 cm diameter, 20 cm length) are used. Plant densities depend upon bag size; bags are usually stacked consecutively. However, spacing with empty rows or wooden boards is recommended. Drainage in these containers is poor and soils tend to be low in organic matter and nutrients. Extensive testing of different container types and substrates and incremental fertilizer regimes on seedling size and field growth is not known. Rooted cuttings have been successfully produced. Substrates studies were conducted by Wightman and Cruz (in review) using different local soil and organic material mixtures, granular fertilizer and copper treated (Spinout) polybags (Negreros Castillo and Wightman, in prep). Seedling growth was significantly better in all soil mixtures than in mixtures with composted vegetation with manure, sugar cane fibers or composted sawdust with manure. Plants grown in these mixtures were chloratic and stunted, while plants of a similar species and within the same Meliaceae family, Cedrela odorata , were grew significantly better with composted materials. Plants grown with in soil with 6 g of 17-17-17 NPK fertilizer per bag did not grow well, possibly because of excessive dose. Copper treated bags did not increase seedling size or root length. Mexal et al (2000) report results using granular fertilizer, triple super phosphate and urea at 0.7-0.9 g/plant/ bag as well as comparing those grown in rigid plastic containers using inert organic substrates and conventional hardwood fertilization. Despite similar plant sizes at the time of planting, fertilized plants grew bigger after 28 and 57 months in the field. Containerized plants did not grow as well as plants produced in bags, however, this is probably due to their very small size at the time of planting. |
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| Establishment Phase: | Seedlings should be shaded during germination, but shade can be removed gradually once first two leaf pairs appear. Germination rates without shade are poor, unless soil moisture is kept high. Stem rot and damping-off were reported in nurseries in Asia; authors recommended the common practices of avoiding overwatering, overshading and application of fungicides. | ||
| Length of Establishment Phase: | one month | ||
| Active Growth Phase: | Seedling should be grown infull sun. Disease problems have not been noted by this author in Mexico, however, micronutrient deficiencies are common when grown in soil substrates. Foliar micronutrient solutions are regularly applied (1 l per 200 l of water), but rates have not been tested. Seedlings are vulnerable to leaf cutter ants; nests should be destroyed (difficult). Occasionally Hypsipyla grandella is present in nurseries and can be easily controlled with systemic insecticides. | ||
| Length of Active Growth Phase: | 2-3 months | ||
| Hardening Phase: | Generally, seedling should receive less water one month before going to the field. | ||
| Length of Hardening Phase: | 2-4 weeks | ||
| Harvesting, Storage and Shipping: | Only the vigorous, healthy plants should be taken to the field; 10% of the crop should be culled. Trees should not be stored from one nursery season to the next. Trees should be well-watered before transport. Trees should be planted at the beginning of the rainy season to maximize growth. However, in many areas, farmers traditionally plant crops during this time, and trees are planted near the end of the rains. | ||
| Length of Storage: | no more than one season | ||
| Other Comments: |
The wood is prized for its workability and reddish brown to yellowish red color and is used for furniture and interior construction. While there are over 100 woods marketed as mahogany from around the world, only those belonging to the Meliaceae family are considered genuine mahogany. The major pests of all mahoganies are the moths of the genus Hypsipyla: H. grandella in the neotropics, and, H. robusta in Africa and Asia. During several generations a year, moths deposit their eggs nocturnally on non-lignified shoots where larvae tunnel downward causing dieback of new growth and subsequent forking. While the insects do not kill the tree, the economic loss due to lost growth and lack of straight bole development is great. When mahoganies are planted outside of their native range, these pests can be avoided. Systemic insecticides, the bacteria Bacillus thuringiensis , the fungus, Beauveria bassiana have been used with some success, but they are generally too expensive or inaccessible to the many small farmers in the tropics. A combination of selected genotypes, frequent pruning, management of shade and lateral vegetation may be the best silvicultural recommendations. Few commercial plantations have been successfully established in Latin America. |
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| References: |
Lamprecht H. 1989. Silviculture in the Tropics. GTZ, Germany. 296 pp. Lugo A. 1999. Point-Counterpoints on the Conservation of Big-leaf Mahogany. USDA Forest Service, Report WO-64. 21p. Mayhew JE and AC Newton, 1998. The silviculture of Mahogany. CABI Publishing. 226 pp. Mexal JG, Rangel Cuevas R, Negreros-Castillo P, and C. Paraguirre Lezama. Successful reforestation of tropical hardwoods in Quintana Roo, Mexico. Proceedings of PRONARE Conference Nov. 2000, Mexico. Monsalvo, VS, Estrada V. 1998. Microorganismso para controlar el barrenador de brotes del cedro rojo y caoba. INIFAP Veracruz, Mexico. Follecto Tecnico # 25. Patino-Valera F. 1997. Recursos geneticos de Swietenia y Cedrela en los Neotropicos: propuestas para acciones coordinadas. FAO, Rome. 58 pp. Salazar, R. 2000. Manejo de semillas de 100 especies forestales de America Latina. Vol. 1. CATIE, Costa Rica. Wightman KE and B Santiago Cruz. (in review) Ensayos de substratos con cedro y caoba. |
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Citation:
Wightman, Kevyn Elizabeth. 2001. Propagation protocol for production of Container (plug) Swietenia macrophylla King plants Rancho Santa Ana Botanic Garden Managua, Nicaragua, Rhode Island. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/05/05). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.
