logs from damaged residual trees and thinnings as raw materials for lawanit (hardboard) factory (lawanit is a form of reconstituted wood). However, in August ...
RESEARCH INFORMATION SERIES ON ECOSYSTEMS Volume 14 No. 3 September – December 2002
Yemane
Gmelina arborea (Roxb.) Compiled by Levi V. Florido Apolinaria T. Cornejo
Issues and Facts on Yemane Compiled by Concepcion M. Palaypayon Jose M. Batalon
Foreword Yemane is known for its very remarkable growth rate. In three years, one can attain a merchantable timber size of 5.8 m – 8.3 m with 10 cm – 15 cm diameter. Likewise, at this age, it is already a prolific seeder. Yemane is a raw material for pulp and paper making, posts, house timbers and poles, and its wood is sawn for general carpentry, joinery, and furniture components. It is also an ideal material for musical instruments and boat decking. Rotary cut veneers are utilized for plywood. It is sometimes used as fuelwood and feed for cattles. Being a multiple-use species, yemane has gained prominence not only in the Philippines but to some of our Asian neighbors as well. Owing to its importance, we have updated and revised the previous versions of RISE issues on this species. We included the issues and facts on yemane to come up with a new reference material.
CELSO P. DIAZ Director
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Yemane
Gmelina arborea (Roxb.) Common name: Yemane; gmelina; melina Scientific name: Gmelina arborea Roxb. Family:
Verbenaceae
Description Yemane is a deciduous tree which has a very remarkable growth rate. In a reasonably good site, it takes only three years to attain a merchantable timber size of 5.8 m – 8.3 m with 10 cm – 15 cm diameter. It is a short-lived tree but with good soil condition and proper care and maintenance, it is capable of surviving from 30 to 40 years. Production may exceed 30 m3 per hectare every year. It is a prolific seeder even at a juvenile age of three to four years. it is considered a drought and fire resistant species. Leaves are opposite; deciduous; entire, 10 cm – 20 cm long, 7 cm – 13 cm wide, and have waxy bloom on the underside. Flowers are numerous, trumpet-shaped, hairy and short-stalked, and has a length of 4 cm. The panicle cymes of yellow or brown flowers are 15 cm to 30 cm long which appear after the leaves drop. The fruits are 2 cm – 2.5 cm long, containing 1 – 2 and sometimes, 3 seeds. Bark is thin and gray colored. Uses Yemane is primarily used for pulpwood production because of its relatively high yield of kraft pulp and low chlorine requirement. Its wood is sawn for general carpentry, joinery, furniture components, and other household fixtures. It is ideal for musical instruments and boat decking. The round timbers are used for posts, house timbers and poles while rotary cut veneers are utilized for plywood. It can also be used as fuelwood. Distribution The species is native to India, Pakistan, Northern Rhodesia, and Malaysia. It is widely planted throughout the Philippines. Plantation of yemane in the Philippines started in the provinces of Cebu and Nueva Vizcaya.
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It thrives well on sites with an elevation of up to 525 m (1,750 ft) above sea level (m asl). It can tolerate acidic, calcareous (soil containing sufficient calcium carbonate), and lateritic soil (any reddish soil developed from weathering composed mainly of oxides of iron, aluminum, titanium, and manganese). However, the species prefers loamy, welldrained, moderately fertile soil. When planting, holes should have sufficient depth. Plant should be free from competition at an early age until its crown had closed. Vigorous growth can be observed in sites under monsoonal climate with distinct dry period. The humidity should not be too low and the area should have 750 mm – 4,500 mm rainfall per year with air temperature ranging from 21oC to 28oC for optimum growth.
Figure 1. Representative sketch of Yemane’s (Gmelina arborea) leaf pattern, fruit, and stone parts Propagation Yemane can be propagated be seeds and cuttings. Seed technology Collection Table 1. Dates and places of collection of mature fruits of yemane. Date February March April May-June July-August
Place Negros, Cebu Nueva Vizcaya, Negros, Cebu, Zamboanga Agusa, Negros, Tarlac, Cebu, Nueva Vizcaya Cagayan, Nueva Vizcaya, Negros, Cebu, Pagbilao, Laguna Samar, Abra, Mindoro, Capiz
Mature fruits are collected after they have fallen to the ground. Fruits that are yellowishgreen can also be collected by shaking the branches.
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Seed extraction For fresh fruits, soften the pulp by soaking in tap water for one week. Fruits in the advance stage of softening only take about one day of soaking. After soaking in tap water, macerate the flesh against a half-inch meshwire. Finally, separate the seeds by letting the macerate pulp float in tap water. Seed count: 1995 seeds/kg Drying and storage Airdry the seeds for 5 – 7 days. They can be stored with or without fungicide dressing to attain 7% - 8% moisture content at 7oC – 8oC. Seeds stored at room temperature remain viable only for 2 – 3 months. Pregermination Soak seeds in tap water overnight prior to sowing. Sowing Bury the pointed end of the seed and the opposite end in level with the soil surface. To protect the seeds from bird or rodent attacks, cover the seedbeds with mesh wire mounted on a wooden frame. Use sandy loam soil as germination medium. The soil is made firm by thoroughly watering before sowing. Then, sow the seeds 6 cm – 8 cm apart within rows and 8 cm – 10 cm between rows. Germination period usually takes 12 – 15 days. Nursery practices The following are the steps in the nursery operation: 1. Prepare raised germination beds about 1 m wide of desired length. Remove stones and undercomposed organinc matter. Pulverize and level the clods. 2. Sow seeds 6 cm – 8 cm along rows and 8 cm – 10 cm between rows to attain production of seedlings with large stems and more fibrous roots. Cover lightly with soil, preferably compost litter. 3. After sowing, water the beds using sprinkler. Do this twice a day to make sure that seeds and soil are sufficiently wet. Shading is not necessary except for newly planted seeds. 4. Regulate the time of sowing in order to produce stumps not larger than 5.08 cm or 2 in in diameter at the time of planting. Germination usually takes place two to four weeks. 5. Outplant woody seedlings that have attained pencil thichness.
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Plantation establishment The following are recommended for establishment and maintenance of yemane plantation: 1. Plant 7 – 10 month-old stumps and seedlings from May to July or during the rainy season in dug holes spaced at 2 m x 3 m. 2. Wrap the root system of the seedlings with wet sack, banana leaves or sheath (i.e. a hundred seedlings per bundle) to avoid dissipation when transporting. 3. Ring weed outplanted seedlings to liberate them from shrubs, grasses, sedges and other ground cover vegetation. This is necessary for the first year only, after which the dense canopy of gmelina suppresses the weeds. The most appropriate time to weed the plantation is during the early and latter part of the rainy season. Avoid weeding during dry months. 4. About 30 days after outplanting, apply complete fertilizer (14-14-14 or 15-15-15) at the rate of 100 kg/ha to improve growth and survival. Trench about 5 cm deep and 5 cm away from the base of the seedlings. Place fertilizer in this trench and cover with soil. 5. Remove overlapping branches, bent and low stems in cleaning and tending operations during the first and second year. 6. The second fertilizer application is usually done during the first weeding/cleaning operation. This is carried out at the latter part of the rainy season or about 90 days after outplanting. Diseases Sooty mold Symptom:
Leaves, petioles, twigs, and branches are partially or completely covered with black mycelial colonies of fungus. The leaves become grayish black and later turn to dirty brown and defoliate.
Causal pathogen:
Meiola clerodendricola
Control measure:
If damage is serious, control first the insect using organic phosphorus chemicals. Improvement of environmental conditions through thinning or pruning are also effective measures in suppressing sooty mold disease.
Brown leaf spot Symptom:
Production of water-soaked and necrotic lesions at the base of the stem of infected seedlings causing wilting and toppling of seedlings over the seedbeds.
Causal pathogen:
Rhizoctonia solani Kuhn, Sclerotium spp., Fusarium spp., Pythium spp., and Pythopthora spp.
Control measures:
1. Sterilize soil for 7 – 8 hrs at 180oC with intermittent spraying of water before putting in seedboxes.
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2. Disinfect soil before seeding. Drench soil with diluted emulsion of Thiram or Captan (3 – 6 li/sq m of soil). Soil burning is also recommended. 3. Seed treatment. Dress the seeds with Thiram fungicide (0.13% wt of seeds) or with Delsene MX (2.5 li/kg of seeds). 4. Seedlings should be kept in well-drained soil. 5. Soak seedlings in fungicide solution for 5 hrs (Benlate at 2.5 g/li of water) before transplanting to plastic pots. Pests Lepidopterous defoliators Chrysodeixis chalcites, Archerontia lachesis and Attachus spp. These have been observed seriously infesting seedlings in nurseries and plantations in Nueva Ecija. Their larvae feed occasionally on leaves, leaving only the midribs. Infestation occurs every year. While some plants succumb completely to the attack, some recover to produce new shoots. Control: Spray any of the Carbaryl insecticides such as Sevin 85S, Vetox 85 WP or Carbin 85S at the rate of 15 – 25 tablespoons per 100 li of water at a five-day interval. Spray the leaves when egg masses and larvae are noticed. Ozala minor A monophagous species which occurs in the early part of May and in the middle part of July, recurs in the latter part of November and ends in the latter part of January. It actively feeds at early in the morning and late in the afternoon. Newly hatched larvae feed on any part of the leaves which later become perforated. Leaf margins are sometimes eaten. Young larvae prefer newly opened leaves although mature larvae also feed on older leaves. When infestation is extremely heavy, the entire leaf may be consumed except the midribs and large margins. Pest is likely to be serious in seedlings and young stands where more growing shoots occur. Leaf cutter ants. These can be controlled by insecticides or poisonous gases provided the expenditure or cost is justified and application is done with proper caution. It can also be controlled by the use of small explosives.
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References Commonwealth Foresty Institute. 1873. Fast growing timber trees of the lowland tropics. No. 1 Gmelina arborea. Compiled by A.F.A. Lamb. Senior Research Officer. Department of Forestry, University of Oxford. 31 pp. Florido, L.V. 1978. Vegetative propagation by cuttings of yemane (Gmelina arborea Roxb.) using growth hormone. Sylvatrop, Philippine Forest Research Journal. 3(2):115 – 122. Florido, L.V. and A. Deogracias. 1983. Growing yemane (Gmelina arborea Roxb.) and Mollucan sau [Albizia falcataria (L.) Back.] in Palawan. Paper presented at the 9th FORI Anniversary Symposium, FORI, College, Laguna December 15, 1983. De Guzman, E. 1975. Study of diseases affecting forest trees in the nurseries. Research Reports. 1975. 296 – 299. Heinsleigh, T.E. and B.K. Holaway. 1988. Agroforestry species for the Philippines. Funded by the US Peace Corps. Washington D.C. 404 pp. Lapis, E. and Z.N. Genil. 1979. Biology of Ozola minor Moore (Lepidoptera Geometridae) a defoliator of yemane (Gmelina arborea). Sylvatrop. Philippine Forest Research Journal. 4(1):31 – 37. Mendoza, V.B. and A.V. Glori. 1976. Fertilization of yemane (Gmelina arborea) in Carranglan, Nueva Ecija. Sylvatrop, Philippine Forest Research Journal. 1:138 – 141. . 1979. How to grow yemane in cogon and Themeda grasslands. Canopy International. 5(12):10:14. Zabala, N.Q. 1977. Field grafting of yemane (Gmelina arborea Roxb.) and large leaf mahogany (Swietenia macrophylla King). Pterocarpus. Philippine Science Journal of Forestry. 3(1):81 – 86. Zamora, R.A. and A.C. Agpaoa. 1976. Months for planting gmelina stumps of different ages. Sylvatrop, Philippine Forestry Research Journal. 1:38 – 43.
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Issues and facts on Yemane Introduction Yemane (Gmelina arborea Roxb.) has gained prominence not only in the Philippines but also among our Asian neighbors because of its economic importance. It is a raw material for pulp and paper making, posts, house timbers and poles while rotary cut veneers are utilized for plywood. It is also utilized as fuelwood and sometimes as feed for cattles, being a multiple-use species. Nueva Vizcaya and Cebu were the two provinces that pioneered in planting yemane. Other plantations were established later in Mindanao and Luzon. Martin Reyes, retired assistant director of then Forest Research Institute, visited the Nasipit Lumber Company (NALCO) in 1975 and 1992 and observed that NALCO had extensive plantations of yemane. Pulpwood-sized yemane logs have practically replace lauan mill wastes and logs from damaged residual trees and thinnings as raw materials for lawanit (hardboard) factory (lawanit is a form of reconstituted wood). However, in August 1993, the Ecosystems Research and Development Bureau (ERDB) received inquiries and reports from Region X pertinent to the following allegations: - Yemane depletes the acquifers of water and affects water quality - It is allelophatic to other vegetations, and - Toxic to animals like cattle. But there is no existing literature on the harmful effects of yemane on the environment and animals. Hence, this primer tackles some issues and facts about yemane to shed light on reports spreading in Mindanao. Issues and facts Issue No. 1. Does yemane deplete the acquifer of water and affect its quality? Yemane does not affect water in streams. It cannot deplete acquifers of water because the roots of the species are mostly situated within 3 m below soil surface, whereas water tables are located several meters deeper. Experiments in ERDB have proven that when yemane was planted in the Bureau's gauging station in San Lorenzo, Angat, Norzagaray, Bulacan, water yield increased by as much as 12%. Thus, the drying up of streams in some localities may be attributed to the loss of vegetation cover in the head waters which are principal sources of underground water in acquifers. This groundwater feeds the stream after occurrence of rainfall and more particularly during the dry season. Results of a one-year study in Diadi, Nueva Vizcaya indicated that yemane is an excellent plantation species. It can easily be established in plantations because survival of the seedlings is not adversely affected by the extremities of site, soil, and biotic factors. Yemane was observed to be resistant to drought, fire, wind damage, and exposure to intense heat of the sun.
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Issue No. 2. Is yemane allelophatic to other vegetations? So far, observations in Burma and India indicate that yemane is normally mixed with other tree species like teak (Tectona grandis), Anogeissus acuminate, and Carega arborea. They are situated mostly in flat or nearly flat ground in deep, alluvial soils. In Cavite and Bukidnon, growth of young crops is not affected by yemane. In fact, coffee under yemane plantation grows vigorously in the province of Cavite (Limsuan 1993). While Reyes (1993) observed that in Benguet, three-year-old coffee plants interplanted under seven-year-old yemane plantation spaced at 2 m x 2 m appeared to be stunted and remained 10 cm – 15 cm in height. This could not be attributed to the allelophatic effects but rather to the very close spacing of the plantation. The roots of some coffee seedlings are observed to have been intertwined with the rootlets of two adjacent yemane trees 5 m – 8 m tall. Fallen leaves of yemane partially covered the ground which may be another cause of the stunted growth of coffee plants. Issue No. 3. Is yemane toxic to animals like cattle? No documented report has been published on the toxicity of yemane on animals. Conversely, the National Academy of Sciences (1981) reported that yemane produces abundant nectar from which high quality honey is processed. Hensleigh (1988) and Little (undated) also reported that deer and rabbits eat yemane seeds and foliage. Likewise, cattle feed on foliage and bark of trees. In Cebu, yemane fruits are made into jam, while in an experimental farm in Angat, Bulacan, the bark was observed to be eaten by deer. These reports showed the nontoxic properties of yemane to animals and man. Issue No. 4. Is the wood of yemane durable or nondurable? Generally, the wood of yemane is rated as nondurable. However, denser heartwood is moderately durable and resistance to termite attack varies.
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References Commonwealth Forestry Institute. 1973. Fast growing timber trees of the lowland tropics. No. 1. Gmelina arborea. Compiled by A.F.S. Lamb. Senior Research Officer. Department of Forestry. University of Oxford. 31 pp. Heinsleigh, T.E. and B.K. Holaway. 1988. Agroforestry species for the Philippines. Funded by the US Peace Corps, Washington D.C. 404 pp. Limaye, V.D. 1933. The physical and mechanical properties of woods grown in India. Third Interim Report on Project 1. Indian For. Rec. 18(10):1 – 70. Limsuan, M.P. 1993. Personal communication. Little, E.L., Jr. (Undated). Common fuelwood crops. Communitech Associates, Morgantown, West Virginia. McClain Printing Company, Parsons West Virginia. pp. 167 – 170. National Academy of Sciences. 1980. Firewood crops: Shrubs and tree species for energy production. Vol.1. Washington D.C. pp. 46 – 47. Research Information Series on Ecosystems (RISE). Vol. 1 No. 2. August 1989. pp. 3–4. Reyes, M.R. 1993. Written communication on ERDB. Sazon, A.C. 1972. Slope and spacing study of yemane in Nueva Vizcaya plantation. Occasional paper No. 43.
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