Agriculture Reference
In-Depth Information
Agriculture —
Attempts to grow
Aspalathus linearis
outside its natural home in South Africa
have not been successful. PROTA4U
1140
outlined the following methodology: The seeds must first be
scarified and then planted in acid, sandy soils. The local rooibos tea management board supplies seeds
that have been treated and germinate easily. They are planted in seedbeds in March to a depth of 5-10
cm and are ready for planting out by July. Plants are generally rainfall dependent but prefer not to be
too wet. No fertilizing is required, and the plants grow quite well in nutrient-poor conditions. Seedlings
are transferred to plantations. It takes 12-18 months before the shrubs are ready to be harvested. They
are harvested once each year, from December through April for a period up to 5 years. They are then
pulled out, and new plants are planted. The basic method of rooibos harvesting has remained largely
the same as the process used centuries ago. An environmentally friendly way of harvesting tea is used
that involves cutting only the young branches. Once they are cut, they are neatly bound and transported
to the process yards. The older branches are left on the tree, and the bushes become slightly taller every
year. The tea cuttings are chopped very fine and then bruised to ensure that the important chemical
reaction that develops the characteristic color and flavor of the tea can take place. After watering and
airing, the tea is left to “sweat” in heaps, and it is at this point that the tea acquires its typical reddish-
brown color and develops its sweet flavor. After the sweating process has been completed, it is spread
out in a large drying yard to dry in the sun. The rest of the process involves sorting and grading the
tea according to length, color, and flavor. The finished rooibos is finally weighed, bagged, and sold to
companies that pack the product in either teabags or in loose-leaf form under their own brand names.
1140
ASPARAGUS AFRICANUS
Botanical Name —
Asparagus africanus Lam.
Synonyms —
Protasparagus africanus
(Lam.) Oberm.
Family —
Asparagaceae
African Names —
Bambara: sogoba kenessi; Falor: simboul; Fulani: pelol fouru, nombo; Ga:
adende, enene; Hausa: sark'a, sansarin kura; Malinke: inaniaga; Mende: ningei; Tukulor: narari;
Wolof: narara; Yoruba:aluki, kadankobe
Description —
The plant is a member of the plant subfamily Asparagae (Liliaceae). It is a tall,
climbing undershrub, with wiry stem and small white fragrant flowers.212
212
Habitat and Distribution —
Members of the genus grow in the savanna and deciduous forest
zones of West Africa and parts of East Africa. It is distributed from Guinea to Kenya.
Ethnomedicinal Uses —
Several species of
Asparagus
yield edible fruits or leaves. The cladodes
(leaves) are used as an external application when crushed to stimulate hair growth in women. In Sudan,
the plant is administered for diuresis and as a remedy for syphilis. It has also been used as a poultice
for the treatment of swellings and guinea worm sores and internally as a remedy for hematuria.
Constituents —
Saponins, named A4-A8, have been isolated from the roots of
A. racemosus
.
One of the saponins, A4, yields glucose and rhamnose on hydrolysis with acid sarsapogenin.
213
Pharmacological Uses —
The root extracts of the related
Racemosus
have been shown to
possess cardiotonic and antioxytocic effects.
214,215
The plant exhibited an inhibitory effect against
Entamoeba histolytica
218
and showed galactogogue effects, which were accompanied by an increase
in weight of the mammary glands in rats
219
as well as in buffaloes.
114
Dhar et al. reported the
in vitro
activity of extracts of the plant against human epidermal carcinoma of the nasopharynx.
216
An aqueous extract of the root has been shown by Thatte and Dhanukar to exert immuno-
therapeutic effects in diverse experimental infections.
217
It was found that the extract protected rats
against mortality induced by intra-abdominal sepsis following cecal ligation. In the animals treated
with the extract, only 27.2% mortality occurred compared to 66-100% recorded for the untreated
group on the 5th day. The extract and the serum from rats treated with
A. racemosus
were devoid
of any
in vitro
antimicrobial activity, which indicated that the mechanism of protection against
