Online Manual for the Forest Tree Seeds of Kerala

A Kerala Forest Department Funded Project


Dr. K Sudhakara
Professor & Head of the Department
Dept. of Silviculture & Agroforestry
College of Forestry, Kerala Agricultural University, Thrissur 680 656
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Scientific Name  Hopea parviflora Bedd.
Vernacular name  Kambakam, Thambakam, Irumbukam, Urippu (Malayalam); Irumbugam, Vellai Kongu, Pongu (Tamil); Bovige (Hindi) (Chacko et al., 2002); Kongu (Gamble, 1922).
Common name  Iron wood of Malabar (Bose et al., 1998); Hopea (Chacko et al.,2002).
Synonyms 
Family  Dipterocarpaceae
Subfamily 
Origin 
Distribution  Common in moist tropical evergreen forests of the Western Ghats. Found in Kerala, Tamil Nadu and Karnataka. Fairly common in the Western Ghats from Karnataka, Kerala and extends to Tirunelveli district of Tamil Nadu (FRI, 1980). In Kerala, it is found in the evergreen and semi-evergreen forests (Chacko et al., 2002).
Description  A large evergreen tree with a dense crown reaching 30 to 37 m height and 4 to 4.5 m breadth (Bose et al., 1998).
Flowering season  January to February (Troup, 1921), March to April (Bose et al., 1998). Flower during the last week of March to first week of April (Sunilkumar and Sudhakara, 1998).
Fruiting season  May and June(Troup, 1921). Fruits ripen by the end of May (Sunilkumar and Sudhakara, 1998).
Flowers  Small cream coloured fragrant flowers, tomentose, in lax panicles of unilateral cymes; calyx segments lanceolate, grey tomentose (Bose et al., 1998).
Fruits  They are small nuts, black, ovoid, apiculate with two straw coloured wings.
Fruit type 
Seeds  Light seeds. At the time of shedding, seeds have a moisture content of 41% (wet weight basis). Among the seed components, the embryo has the highest moisture percentage (Sunilkumar and Sudhakara, 1998).
Seed length  0.7 cm (Tompsett and Kemp, 1996; Chacko et al., 2002).
Seed width  0.6 cm (Tompsett and Kemp, 1996; Chacko et al., 2002).
Seed thickness 
Seed weight  2,470 fruits /kg (with wings) (FRI, 1980; Chacko et al., 2002); 4,100 to 4,586 seeds/kg (without wings) (Tompsett and Kemp, 1996; Chacko et al., 2002)
Seed dispersal  Wind dispersal.
Seed Collection  Fruits may be collected from the tree when the wing colour changes from green to brown (Tomposett and Kemp, 1996). Seed collection from tree is laborious. Mature seeds falling during the pre-monsoon showers, can be conveniently collected from the ground. As the fallen seeds germinate soon, collection may be done soon after seed fall. Always check a small sample of seeds before collecting, since insect infestation may be excessive in some localities (Chacko et al., 2002).
Transportation of seeds  The fruits are transported ventilated containers. If the wings are left intact, a reservoir of air is created which provides support for respiration; this method will limit both the imbibition of moisture and the accumulation of heat produced by respiration, thereby reducing the chance of germination during transport. Polythene bags with small ventilation holes, and open-weave sacks are different types of containers used for transport. Where greater rigidity is required, these containers should in turn be closed in cardboard or wooden boxes provided with ventilation holes (Tompsett and Kemp, 1996; Chacko et al., 2002).
Seed processing  Wings are removed for ease in handling and reduction of bulk (Tompsett and Kemp, 1996; Chacko et al., 2002).
Seed storage  Recalcitrant (Tompsett and Kemp, 1996; Chacko et al., 2002). Seeds can be stored for about a week without loss of viability under normal conditions (Dent, 1948). For larger quantities of seed, storage at or near harvest moisture content in media such as softwood sawdust (16% moisture content) and perlite (0 to 4% moisture content) is recommended (Tompsett and Kemp, 1996; (Chacko et al.,2002). The critical moisture content of the seeds of H. parviflora is 26% and those of H. ponga was 28%. When subjected to desiccation in a freezer (0+or-2oC) the seeds of H. parviflora will loose their viability within six hrs, and those of H. ponga within four hrs. The duration for initiation and completion of germination increases when the temperature is decreased to below 20oC and the seeds fail to germinate at temperatures below 5oC. The germination and vigour of the seeds germinated between 30 to 35oC are high, but the optimal temperature for germination of the seeds of the two species is 30oC (Dayal and Kaveriappa, 2000). Germination is maintained in storage in mud pots with or without sand medium. When seeds are treated with Emisan (1% a.i.) and stored at 10oC, 87% germination will be obtained at the end of 40 days. Storing at 10oC without Emisan result in markedly decreased germination percentage (18%). Treatment with Emisan will not affect the germination parameters (Sunilkumar and Sudhakara, 1998). Storage at temperature 10oC and 4oC retain the viability up to one and four weeks for the intact and synthetic seeds, respectively. Both synthetic seeds and intact seeds stored at room temperature (27+or-2oC and 29+or-2oC, respectively) retain the viability only up to one week with approximately 30% germination. Synthetic seeds obtained from seeds pre-treated with 2 and 3 mg/litre abscisic acid show tolerance to low storage temperature and retain higher percentage germination (Sunilkumar and Sudhakara, 2000).
Viability period  Seed is viable up to 10 days under normal conditions (Chacko et al., 2002). Intense rainfall at the time of fruit ripening often induces vivipary of most of the seeds (Sunilkumar and Sudhakara, 1998).
Seed emptiness  Low (Chacko et al., 2002).
Seed pre treatment  De-winging prior to sowing is recommented. Ideal germination temperature is 31oC (Tompsett and Kemp, 1996; Chacko et al., 2002).
Germination type  Epigeous (Chacko et al., 2002).
Germination percentage  68 to 84 (Tompsett and Kemp, 1996 from Chacko et al., 2002). Seeds sown immediately after collection gave 96% germination. After 12 days of storage, seeds had lost 39% of the initial moisture content and were not viable (Muralikrishna and Chandrashekar,
Germination period  11 to 37 days (Dent, 1948; Chacko et al., 2002).
Nursery technique  Seeds may be dibbled in vermiculite or river sand medium (in trays) with or without wings, horizontally or with wings downwards. Germinated seedlings can be pricked out to polythene bags or root-trainers filled with appropriate potting mixture (Chacko et al., 2002).
Method of propagation  Vegetative propagation.
Vegetative propagation  Branch cuttings of 2 mm to 3 mm thickness and 7 cm length when dipped for one minute in IBA 2000 ppm solution results in 30% rooting and sprouting (Chacko et al., 2002).
Pests  High infestation due to Bruchus chinensis Lin. (Coleoptera: Bruchidae) (Chacko et al., 2002).
Diseases  High (67%). Seeds are harboured by a rich microflora. Nineteen fungi, actinomycetes and bacteria are recorded on seeds. Fusarium sp., Botryodiplodia theobromae, Cylindrocladium quinqueseptatum are the important field fungi associated with seed discolouration and rot (Chacko et al., 2002).
Medicinal properties  The tannin content ranges from 14 to 28% of the exudate and is very astringent with a slow rate of diffusion. Used to keep off land leeches (Nazarudeen, 2003).
Uses  Wood is used for building purposes, piles for bridges, platform boards, ladders, carts, carriages, turnery etc. The bark contains tannin used in leather industries (Bose et al., 1998).
Wood properties  Wood brown and close grained, strong and durable. Pores small and moderate sized. The average air dry weight of wood, 929 kg/m3. Medullary rays moderately broad, prominent, generally bent where they touch the pores, uniform and equidistant (Gamble, 1922).
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