SCHOOL: | ENVIRONMENT AND NATURAL RESOURCE MANAGEMENT | DEPARTMENT: | FORESTRY AND LAND RESOURCE MANAGEMENT | UNIT TITLE: | EMERGING TROPICAL PLANT RESOURCES | UNIT CODE: | ENF 303 | ASSIGNMENT: | QUESTION 1 & 2 | INSTRUCTOR: | MR. OKEYO | STUDENT’S NAME: | RODGERS OYUGI KOGAH | REGISTRATION NUMBER: | I405/0329/2011 | DATE: | 31ST AUGUST, 2013 |

* QUESTION 1. MAKE NOTES ON UNDEREXPLOITED /NEGLECTED PLANT SPECIES HIGHLIGHTING THEIR CLASSIFICATION, TAXONOMY, PROPAGATION, GENETIC RESERVIOUR, MANAGEMENT AND IMPORTANCE.
(a) Albizia lebbeck L.(Woman’s –tongue- tree)
Classification:Underexploited Fodder Plants
Taxonomy.
Kingdom- Plantae
Subkingdom- Tracheobionta
Superdivision- Spermatophyta
Division- Magnoliophyta
Class- Magnoliopsida
Subclass -Rosidae
Order- Fabales
Family- Fabaceae
Genus- Albizias
Species -Albizia lebbeck (L.) Benth. – Woman’s tongue
Common names: * Swahili: Mkingu, mkungu * English: East Indian walnut, frywood, Indian siris, siristree, woman's-tongue-tree,
Propagation
* It is best established using potted seedlings, although bare-rooted seedlings, direct seeding and stump cuttings have all been used successfully. * Seed pretreatment involves scarification and immersion in boiling hot water then cooling and soaking for 24 hours, or acid treatment to break seed-coat dormancy. * Germination improves after storage for 2-4 years, but satisfactory germination (50-60%) has been obtained from fresh seeds. * Freshly collected seed has about 70% germination capacity after 1-2 months. * About 880 pods weigh 1 kg and will yield about 300 g of seed.

Genetic Reservoir * Albizia lebbeck is indigenous to the Indian subcontinent and those areas of south East Asia with a marked dry season (e.g. northeast Thailand, the eastern islands of Indonesia) and the monsoon areas of Australia. * It has been identified widely throughout the tropics and has become naturalized in many places.
Management
* A. lebbeck coppices well, responds to pollarding, pruning and lopping, and will produce root suckers if the roots are exposed. * Typical spacing is 3 x 3 m for fuelwood, and 5 x 5 m for timber. * Fuelwood plantations spaced at 3 x 3 m clear felled on a 10-year rotation produce about 50 cubic m/ha of stacked fuelwood. * In Queensland A. lebbek reaches about 11 m in height and 50 cm dbh in 30 years. * The trees are vulnerable to strong winds and are killed by even light fires. * Seed storage behaviour is orthodox. Viability is maintained for several years in hermetic storage at room temperature with 11-15% mc; even seeds stored 30 years show 5% viability. However, the seed is liable to bruchid attack, which may occur while the pods are still on the tree, so a little contact insecticide should be mixed with the stored seed. * There are about 5000-12 000 seeds/kg.
Importance.
i) Fodder: A. lebbeck is grown in some areas primarily as fodder for camels, water buffalo and cattle. The leaves are reported to be good fodder, with 17-26% crude protein; 100 kg of leaves yield 11-12 kg of digestible protein, and 37 kg of digestible carbohydrates. The pods contain saponin and are not eaten in large amounts by sheep, although cattle eat them readily. ii) Apiculture: Its whitish flowers are fragrant, attracting bees. Highly regarded by bee-keepers for the light-coloured honey its nectar provides. iii) Fuel: An excellent fuelwood species with a calorific value of 5200 kcal/g. iv) Timber: Sapwood is pale; heartwood is dark brown with black streaks and very decorative. It is moderately heavy and hard, strong and fairly durable, with a specific gravity of 0.5-0.6 kg/cubic m. The wood seasons well, works and polishes easily, can be used for interior moulding, parquet, furniture, paneling, turnery and general construction. It is also used for making agricultural implements and mine props. Timber plantations in India clear felled after 25-30 years yield about 10-12 cubic m/ha per year of timber, but under semi-arid conditions and on shallow soils, a mean increment of 2-3 cubic m/ha is obtained. v) Gum or resin: The trunk yields a reddish gum that is used as an adulterant of gum arabic. vi) Tannin or dyestuff: The bark is used locally in India for tanning fishing nets (tannin content of 7-11%). vii) Medicine: Leaves and seeds are used for eye problems, and the bark to treat boils. Saponin from pods and roots has spermicidal activity. viii) Other products: When dried and pounded, the bark can be used for soap. ix) Erosion control: Due to its extensive, fairly shallow root system, A. lebbek is a good soil binder and is recommended for eroded lands and erosion control, for example along river embankments. x) Shade or shelter: The species is commonly grown as a shade tree in pastures, tea, coffee and cardamom plantations, and along avenues. It can be planted in exposed coastal situations and as quick-growing shelter for less hardy plants. xi) Nitrogen fixing: A. lebbeck is not Rhizobium specific, and native strains are nearly always capable of producing an abundance of nodules. xii) Soil improver: The nitrogen-rich leaves are valuable as mulch and green manure. xiii) Ornamental: In India A. lebbeck is often planted along roads and in homegardens.

(b)Macadamia integrifolis(Macadamia nut)
Classification: Underexploited oil seed producing plant species
Taxonomy
Kingdom- PlantaeSubkingdom- TracheobiontaSuperdivision - SpermatophytaDivision - MagnoliophytaClass - MagnoliopsidaSubclass - RosidaeOrder - ProtealesFamily - ProteaceaeGenus - Macadamia Species - Macadamia integrifolia | | | | | | | | | | | | | | | | | | | | | | | |

Common names:
English: Australian bush nut, macadamia nut, Queensland nut, smooth macadamia nut

Propagation * M. integrifolia comes reasonably true to type when raised from seed. * Seeds for propagation are selected from vigorous, heavy-bearing trees. * The fresh nuts are planted with no pretreatment. Grafting may develop desirable clones; side wedge grafting has been used exclusively in Hawaii. * Other vegetative propagation methods include splice grafting and cuttings.
Management
* Seedling growth, initially slow, gathers momentum as saplings produce a series of extension growth flushes in a year. * The juvenile phase lasts for 7 years or more, but grafted trees come into bearing after 3 years. * Correct branching should be induced at an early age after which there should be no further pruning. * During the first 2 years, training (a form of corrective pruning) is done to develop a strong, well-balanced framework for future growth. * The young trees should receive careful attention with respect to irrigation, weed control and frost and wind protection. * They should also be fertilized to make them grow well and induce early flowering. * Mulching is recommended for young trees (when the trees come into bearing, it interferes with nut collection). Fertilizer management should be guided by leaf and soil analysis, the phenological cycle and yield. * Macadamia trees appear to be sensitive to nutrient deficiencies and imbalances, and positive responses to N, P, K, Zn, B, S, Mg, Fe and Cu have been observed.

Genetic reservoir * It is native to Australia but is also grown as an exotic plant in countries like: Brazil, China, Colombia, Ethiopia, Fiji, Guatemala, Indonesia, Kenya, Malawi, Mexico, Peru, Samoa, South Africa, Tanzania, Thailand, United States of America, Venezuela and Zimbabwe.
Importance
1. Oil: Macadamia is the richest oil-yielding nut known. The kernel contains more than 75% oil, suitable for human consumption. Essential oil: The characteristic, subtle macadamia flavour is probably due to volatile compounds, the major ones being similar to those in other roasted nuts. 2. Food: The fine, crunchy texture, rich cream colour and delicate flavour make the macadamia nut one of the finest dessert nuts. The eating quality of the nut is enhanced by lightly roasting it in coconut oil and salting. Raw kernels are also popular alone or in a wide range of confectionery and processed foods. The quality of the kernel is related to its oil content and composition. Nuts are mature when the kernels accumulate 72% or more oil, as determined by specific gravity. Kernels also contain 10% carbohydrates; 9.2% protein, which is low in methionine; 0.7% minerals, particularly potassium, and niacin, thiamine and riboflavin. Apiculture: Macadamia pollen is very attractive to bees, providing necessary forage for honey production. 3. Fuel: Macadamia shells may be used as fuel, generating sufficient energy to dry wet, in-shell nuts. 4. Tannin or dyestuff: The hulls, the green covering of the nuts, contain approximately 14% of substances suitable for tanning leather. 5. Shade or shelter: M. integrifolia makes an excellent evergreen shade and shelter due to its thick crown of leaves. 6. Soil improver: The decomposed husk is commonly used in potting soil. 7. Ornamental: As well as being an evergreen nut-bearing tree, M. integrifolia has good symmetrical shape and when in full bloom is covered with creamy-white and pinkish flowers in long, narrow, drooping racemes. These make it a popular ornamental tree. 8. Intercropping: Inter-row cropping can be practised with trees such as citrus, if they are removed at 12 years. Macadamia will retard the growth of papaya planted near it.

(c) Colocasia esculenta (L.)(Coco yam)
Classification:Underexploited roots and tuber plant species
Taxonomy
Kingdom- Plantae
Phylum- Magnoliophyta
Class- Liliopsida
Subclass- Arecidae
Order- Arales
Family- Araceae
Genus- Colocasia
Species- Colocasia esculenta

Common names: * English: Taro, dasheen, eddoe, cocoyam, elephant ear * Luo : Nduma
Propagation
* Colocasia species are usually vegetatively propagated with the preferred method being from suckers or sets (top piece of the corm with the bases of leaf petioles still attached). * The plants are therefore planted in such a way as to encourage sucker growth e.g. the use of larger plant spacing and shallow planting. * The planting material is set in furrows or ridges and plant spacing can be anywhere between 30 to 100 cm (11.8–39.4 in) between plants depending on the prevailing soil and climatic condition. * A narrow spacing helps to control weeds whereas a wider spacing is preferred in growth.
Management
* Taro requires good soil fertility and adequate organic matter. * Flooded taro requires greater quantities of fertilizer for maximum yields than upland taro. Potash is particularly important and the crop also has a relatively high calcium requirement. General recommendation for taro is 40–80 kg/ha N, 15–30 kg/ha P and 50–100 kg/ha K. Some farmers in Ghana use organic manure (mainly from poultry) resulting in appreciable yields. * Since the crop grows best in conditions where water is non-limiting, water management is a key factor. In situations with abundant water availability. * Closer spacing is advised; also when taro is intercropped it can be planted closer. * Weeding is necessary until the canopy closes; in flooded cultivation growth of weeds is limited, and they can be easily controlled mechanically.
Genetic reservoir | | * Colocasia esculenta occurs wild in tropical Asia extending as far east as New Guinea and possibly northern Australia. * A type with long stolons occurring throughout this region has been postulated as the ancestor of cultivated taro on the basis of ribosome-DNA analysis. Taro is believed to have been domesticated in northern India, but independent domestication in New Guinea has also been suggested. * Distribution to China and via Arabia to Egypt and East Africa also occurred at least 2000 years ago. From there taro was taken by Arab people to West Africa. It was introduced into Europe from Egypt. * Eddoe types (having a central corm and many large cormels) may have originated in China, from where they spread to the Caribbean region, and from there to Africa. * Presently taro is grown in many parts of the tropics and subtropics, as a tuber crop and leafy vegetable.
Importance
1. The soft white-fleshed corms of taro are eaten boiled, fried or roasted as a side dish or are used for making fufu. They are popular as they quickly satisfy hunger, even when only a small amount is eaten. In cultivars with a single large main corm (dasheen type) the product is comparatively mealy, whereas in eddoe types the cormels have a more firm structure and taste somewhat nutty. The corm is also sliced and fried into taro chips and is used in the preparation of soups, beverages and puddings. It is well tolerated in the diet of allergic children and adults with gastro-intestinal disorders. It is said to reduce dental decay in children. The starch is used in baby foods and as cereal substitute. 2. Medicinal uses: In Gabon raspings from the corm are applied as a poultice to maturate boils, and to treat snakebites and rheumatism. In Mauritius boiled young leaves are eaten to treat arterial hypertension and liver affections, whereas juice is applied externally to treat eczema. In Madagascar the corms are used to treat boils and ulcers. In Gabon the leaves in combination with leaves of Tephrosia sp. are reportedly used in fish poison. Fiber obtained from the leaf stalk has been used for plaiting.

* QUESTION 2. DISCUSS THREE UNDEREXPLOITED PLANT SPECIES WHICH ARE MULTIPURPOSE HIGHLIGHTING THEIR CLASSIFICATION,PROPAGATION,GENETIC RESERVIOUR AND IMPORTANCE

a) Prosopis juliflora (Mathenge)
Classification:Underexploited multipurpose plant species
Common names: * English : Mathenge(Kenya), Prosopis, mesquite, algarroba, ironwood * Turkana: Eterai
Propagation
* Propagation is by seed, root cuttings or grafting. * Establishment by seed is feasible, although seed is difficult to extract from the pods. * Pretreatment is either by soaking for 15-20 minutes in sulphuric acid followed by thorough washing in cold water or by mechanical scarification; 80-90 % of the seeds germinate in 4-6 days. * Aerial seeding is applied successfully to quickly cover remote, extensive and poorly accessible areas. * Inoculation with Rhizobium and mycorrhizal fungi is advantageous.
Genetic reservoir * Originally Central and/or South American, the mesquite is now pantropically introduced and establishing, often as a weed. * It is also currently grown in Kenya. It’s an invasive species but is being encouraged for its multiple uses. | |
Importance
1. Pods are made into gruels, sometimes fermented to make a mesquite wine. 2. The leaves can be used for forage. 3. Providing good bee pasturage also, nectar from mesquite yields a superior honey. 4. The wood is used for parquet floors, furniture, and turnery items, fencepost, pilings, as a substrate for producing single-cell protein, but most of all for fuel. 5. Toasted seeds are added to coffee. 6. Bark, rich in tannin, is used for roofing in Colombia. 7. The gum forms an adhesive mucilage, used as an emulsifying agent. Gum is used in confectionary and mending pottery. 8. Roots contain 6–7% tannin, which might discourage Rhizobia.

b) Azadirachta indica(Neem Tree)
Classification:Underexploited multipurpose plant species.
Propagation
* The tree is easily propagated - both sexually and vegetatively. * It can be planted using seeds, seedlings, saplings, root suckers, or tissue culture. * However, it is normally grown from seed, either planted directly on the site or transplanted as seedlings from a nursery. * For propagation from seeds, the seeds should be as fresh as possible as older seeds often do not germinate. Provided that only a few trees are to be planted, and there is sufficient moisture available, with minimum weeds, the seeds may be sown directly into the ground. * Two to three seeds are placed together about 1 cm deep in loose soil. After germination, only the strongest plant should be retained. When planting a large number, it is advisable to cultivate young plants first in pots, trays or plastic bags. * After 3 months, they should be transplanted into the ground. When using bags or pots care should be taken that the plants are not allowed to develop to a stage where the tap root has pierced the bottom and has to be shortened before transplantation. This weakens the trees and substantially slows their growth.
Genetic reservoir * The neem tree (Azadirachta indica) is a tropical evergreen tree native to India and is also found in other southeast countries. * In India, neem is known as “the village pharmacy” because of its healing versatility, and it has been used in Ayurvedic medicine for more than 4,000 years due to its medicinal properties. * It is also grown in Kenya especially along the coastal regions.

Importance * Neem oil is extracted from the seeds of the neem tree and has insecticidal and medicinal properties due to which it has been used for thousands of years in pest control, cosmetics, medicines, etc. Please see neem oil & its uses for detailed information. * Neem seed cake (residue of neem seeds after oil extraction) when used for soil amendment or added to soil, not only enriches the soil with organic matter but also lowers nitrogen losses by inhibiting nitrification. It also works as a nematicide. * Neem leaves are used to treat chickenpox and warts by directly applying to the skin in a paste form or by bathing in water with neem leaves. In order to increase immunity of the body, neem leaves are also taken internally in the form of neem capsules or made into a tea. The tea is traditionally taken internally to reduce fever caused by malaria. This tea is extremely bitter. It is also used to soak feet for treating various foot fungi. It has also been reported to work against termites. In Ayurveda, neem leaves are used in curing neuromuscular pains. Neem leaves are also used in storage of grains. * Twigs of neem are also used in India and Africa as toothbrushes. Nowadays toothpastes with neem extracts are also available commercially. * Neem (leaf and seed) extracts have been found to be spermicidal and thus research is being conducted to use neem extracts for making contraceptives. Neem produces pain relieving, anti-inflammatory and fever reducing compounds that can aid in the healing of cuts, burns, earaches, sprains and headaches, as well as fevers. * Neem bark and roots also have medicinal properties. Bark & roots in powdered form are also used to control fleas & ticks on pets. * Neem has anti-bacterial properties that help in fighting against skin infections such as acne, psoriasis, scabies, eczema, etc. Neem extracts also help in treating diabetes, cancer, heart disease, herpes, allergies, ulcers, hepatitis and several other diseases.

c) Psidium guajava L(Guava)
Classification:Underexploited multipurpose plant species
Propagation
* Guavas grown for processing may be propagated by seed; about 70% of seedlings retain the general characteristics of the parent tree. * One fruit will supply over 50 seeds, which should produce at least 25 good quality seedlings. Seed can be sown in beds, pots or directly in the field at a depth of 1 cm; germination occurs within 15-20 days. * They should be planted out when about 25 cm high. The seedling grows very rapidly, producing fruit in 2-3 years on good soils. When grown for their fresh fruit they are clonally propagated. In south-east Asia this is usually done through air-layering, but for larger numbers, shield or patch budding onto seedling rootstocks is recommended. * Trees are ready for field planting after 4-5 months. * Other propagation methods for example using cuttings or grafting, can also be employed. Plants should be about 1 m tall for grafting. * Micro-propagation using nodal explants from mother trees has been reported from India with 70% success in transplantation.

Genetic reservoir * They are native to Mexico, Central America, and northern South America. * Guavas are now cultivated and naturalized throughout the tropics and subtropics in Africa, South Asia, Southeast Asia, the Caribbean, subtropical regions of North America, Hawaii, New Zealand, Australia and Spain. * In Kenya it is an invasive species, it is found mainly in the western parts of the country.

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Importance
1. Food: The whole fruit is edible; flavour varies from very acid to sweet with the best fruit being both sweet and mildly acid. It has a pleasant aroma, is very high in vitamin C (10-2 000 mg/100 g of fruit), and a rich source of vitamin A and pectin (0.1-1.8%). Other varietiesare used to produce products like: canned fruit or mesocarps in sweet syrup, puree, goiabada (a type of thick, sweet jam), jams and jellies, juices and nectars, ice cream and yoghurts. 2. Apiculture: White fragrant flowers secrete nectar in excess all day attracting bees, which also collect juice from the damaged fruits. In India for instance, the blossoms occur in May and June. 3. Fuel: Wood makes excellent firewood and charcoal because of its abundance, natural propagation, and classification as an undesirable weed. 4. Timber: Sapwood light brown, heartwood brown or reddish; hard, moderately strong and durable. It is used for tool handle, fence posts and in carpentry and turnery. 5. Tannin or dyestuff: The leaves and bark may be used for dyeing and tanning. 6. Essential oil: Plant contains an essential oil. The volatile oil with methylchavicol, persein and d-pinene (a paraffin) is found in the leaf. 7. Alcohol: Winemaking from the fruit has been commercialized in southern Africa. Poison: P. guajava has insecticidal properties. 8. Medicine: All parts of the young fruit are astringent. Guava exhibits antibacterial action against intestinal pathogens such as Staphyloccocus. The dried ripe fruits are recommended as a remedy for dysentery, while the leaves and fruits are used as a cure for diarrhoea. Oil contains bisabolene and flavinoides that exhibit anti-inflammatory properties. A decoction of the leaves or bark is taken externally as a lotion for skin complaints, ringworm, wounds, and ulcers. Water from soaking the fruit is good to treat diabetes. The leaves are made into a cataplasm; cooked, they are given to horses with strangle. Some suggested treatments are digestive tract ailments, cold, and high blood pressure: leaf decoction or fruit juice with salt or sugar taken orally. Trauma, pain, headache, and rheumatism: hot leaf decoction compress. Sore throat, hoarse throat: leaf decoction, gargle. Varix, ulcer: leaf decoction, treated with warm water, bath. Hepatitis, gonorrhoea, and diarrhoea: clear fruit juice. 9. Ornamental: Widely cultivated as an ornamental fruit tree

REFERENCES

1) www.prota4u.info/protaindex.asp 2) www.worldagroforestrycentre.org 3) ufdc.ufl.edu/UF00082046/00001/45j 4) www.tropicalforages.info/key/Forages/Media/Html/Albizia_lebbeck.htm 5) www.plants.usda.gov/core/profile?symbol=ALLE 6) www.globinmed.com/index.php?option=com_content&view=article&id=79481:albizia-lebbeck-l-benth&catid=365:a 7) www.hort.purdue.edu/newcrop/duke_energy/prosopis_juliflora.html 8) en.howtopedia.org/wiki/How_to_Grow_Neem_Trees 9) www.extento.hawaii.edu/kbase/crop/crops/i_guava.htm