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  Eucalyptus grandis W. Hill ex Maid.
Vernacular name  Grandis (Malayalam), Thayila maram (Tamil) (Chacko et al.,2002).
Common name  Red gum, Flooded gum (Chacko et al., 2002); Rose gum (Bose et al., 1998).
Family  Myrtaceae
Origin  Native of New South Wales and Queensland, Australia (Chacko et al., 2002).
Distribution  Native of Australia, Queensland and extensively in South Africa, Zambia, Sri Lanka and India.
Description  Fast growing, tall ornamental evergreen tree of 65 m high (Chacko et al., 2002).
Flowering season  Month of summer.
Fruiting season  December to February (Chacko et al., 2002).
Flowers  Inflorescence is a 7-11 flowered umbel, peduncle flattened, to 2 cm long, pedicels angular. Flower buds ovoid or broadly fusiform; operculum conical or rostrate, 3-4 mm long, 4-5 mm wide; hypanthium obconical or campanulate (Bose et al., 1998).
Fruits  Fruit is a capsule, pear shaped with very gradual taper. Fruits subpyriform, to 1 cm long and 0.5 cm broad; disc narrow; valves 4-5, exserted, incurved (Bose et al., 1998).
Fruit type  Capsule.
Seed length  No information (Chacko et al., 2002).
Seed width 
Seed thickness 
Seed weight  200000 to 250000 seeds/kg (Kindt et al., 1997; Chacko et al., 2002).
Seed dispersal 
Seed Collection  The twigs bearing capsules are lopped off the trees and collected on a tarpaulin sheet (Chacko et al.,2002).
Transportation of seeds  The capsules are separated from the twigs and transported in gunny bags (Chacko et al., 2002).
Seed processing  Capsules are dried in shade for a day or two in cloth bags. Seeds released from the capsules are winnowed to remove chaff. The seeds are dried well before storage (Chacko et al.,2002).
Seed storage  Orthodox (Kindt et al., 1997; CABI, 1998). Air dried seeds stored in air tight container retains viability to a fair extent for one to two years (Chacko et al.,2002).
Viability period  Seeds are viable for about 2 years in sealed tins (Chacko et al.,2002).
Seed emptiness  No information (Chacko et al.,2002).
Seed pre treatment  Not required (Carlowitz, 1991; Chacko et al.,2002). Hot water treatments (50oC), surface treatments (10% sodium hypochlorite or 33.3% hydrogen peroxide) and fungicidal application (captan) (Donald and Lundquist, 1988). Covering seeds with rice husks and dried grasses increase germination percentage (Pereira et al., 1981).
Germination type  Epigeal (Chacko et al.,2002).
Germination percentage  35 to 65 (Carlowitz, 1991; Chacko et al., 2002).
Germination period  3 to 8 days (Chacko et al.,2002).
Nursery technique  Seeds are sown in germination trays containing perlite medium or on 12 mm thick polyurethane foam sheets (Chacko and Muhammad, 1986), placed in trays. Germination takes place within 5 to 15 days. The seedlings are pricked out into polythene bags of 20 x 10 cm size filled with potting mixture within three weeks after germination. Seedlings can be raised in root trainers and other types of containers by direct sowing also (Chacko et al., 2002).
Method of propagation 
Vegetative propagation 
Pests  Nil (Chacko et al.,2002).
Diseases  Low (Sharma and Mohanan, 1980; Chacko et al., 2002). Pink disease caused by Corticium salmonicolor; stem canker caused by Cytospora eucalypticola and C. eucalypti (Sharma et al., 1990) and Cryphonectria canker disease. Outbreaks are localised up to 30% of the trees in a stand. Infection usually occurs on the main stem 1-1.5 m above ground and occasionally near ground level (Sharma et al., 1985). Web blight is caused by Rhizoctonia solani, damping-off by Pythium myriotylum and P. deliense, seedling blight by Cylindrocladium camelliae, leaf and shoot blights by C. clavatum and seedling wilt and root rot by Sclerotium rolfsii (Sharma et al., 1984; Mohanan and Sharma, 1985).
Medicinal properties 
Uses  An important timber tree, the wood being resistant to borers, used for boat building, flooring, plywood, panelling and construction works (Bose et al., 1998). Wood is used as a raw material for manufacturing writing, printing, wrapping papers and newsprint. The poles can be used as fencing posts, in construction work, for transmission in electric and telphone lines etc. (FRI, 1984; Chacko et al., 2002).
Wood properties  The wood is very similar to E. globulus in colour and weight and is indistinguishable from it in anatomical characteristics and properties.
References  Get ...
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