Leaflet No. 21

Tree Seed Information Leaflet

Vitex keniensis

Species: Vitex keniensis Turrill.Family: VerbenaceaeCommon name: Meru OakLocal names: Muhuru (Kikuyu)

Muuru (Meru)

Description: Vitex keniensis is a tall deciduous tree up to 35m high with a clear straight bole. Bark is pale brown with vertical grooves. Leaves are compound, divided into 5 leaflets, on a long hairy stalk. Flowers are white or purplish with one dark mauve petal lobe. Mature fruits are black, round, about 1.5cm across, usually containing 1-2 or rarely 3-4 seeds.

Distribution: The species occurs in moist evergreen forest, between 1,300 and 2,100m above sea level. It prefers deep sandy-loam soil in areas with a mean annual rainfall of 1,400-1,900mm. The species is common on the eastern slopes of Mt. Kenya (Meru). It is widely planted in Meru, Nyeri, Mt. Elgon, Londiani, Nandi hills and in Kakamega forests in plantation.

Flowering and fruit development: Flowering occurs between January and April. Pollination is by insects. Seed maturity takes about 5 months. The green fruit of about 1.5cm turns to black when ripe. It contains 1-2 and rarely 3-4 viable seeds. Seed can be collected between June and September.

Method of collection: The mature black fruits are collected from the ground following natural seed fall or by climbing the tree and shaking the branches to release the ripe fruits.

Seed extraction, cleaning and drying: Mature fruits are sun dried and then put in a concrete mixer with ballast at the ration 1:2. The mixture is then tumbled for about 6 hours to erode the dry pulp from the fruit. The depulped nuts are then dried under shade to the required moisture content (10-18%). Nuts are separated from the ballast and cleaned by hand sorting.

Seed weight: There are 1,000-1,700 seed/nuts per kilogram. The number of seeds will also depend on the provenance and the climatic conditions of the ripening year.

Seed storage: Seeds can be stored in airtight containers (plastic, kilner jars, and aluminium packets) in cool dry place for 1-2 years with no significant loss of viability.

Seed Sowing and Germination: Seeds germinate within 18 to 50 days. Pretreatment is not necessary. The expected germination rate of mature and healthy seed lots is 40-60%. Each fruit contains

one large stone/nut, which bears 1-4 seeds (multi-germ). Best sown in a seedbed since several seedlings will germinate from each nut and can be separated when transplanting.

To sow, seeds are spread thinly and evenly on a well-prepared seedbed (containing sand or a mixture of sand and soil) and then covered with a thin layer of soil/sand. Watering is done regularly (morning and evening) until they germinate. The young seedlings are transplanted when they are large enough to handle (4-5 leaves). They are transplanted to pots containing soil mixed with NPK fertilizer at the rate of 30-40 grams per 20liters of soil. Seedlings are planted out when they are 30cm tall (4-6months).

End uses: The tree produces high quality timber used for construction and furniture, production of poles and fuel wood. Other uses include bee forage, mulch, shade and ornamental.

For more information contact

The DirectorKenya Forestry Research InstituteP.O. Box 20412 - 00200Nairobi

Tel: +254 722 259 778/2 +254 722 157 414 +254 734 251 888E-mail: kefri@nbi.ispkenya.comWebsite: www.kefri.org