R & t xanthosoma saggitifoliumPresentation Transcript
Root and tuber crops
Identify the items
• Cocoyams (Colocasia and Xanthosoma spp.)
are stem tubers that are widely cultivated in
both the tropical and subtropical regions of
• the two species mostly grown in West Africa
are Colocasia esculenta and Xanthosoma
• Cocoyams can be processed into several
industrial inputs, food and feed products,
similar to products from potatoes in the
• The processing of the crops include boiling,
roasting, frying in oil, pasting, milling and
conversion into ‘fufu’, soup thickeners, flour
for baking, chips, beverage powder, porridge,
and special food for gastro-intestinal disorders
• Cocoyam leaves are used in many homes as a
leafy vegetable (pot herb) and can also be fed to
poultry as greens
• It is also reported to be one of the most
promising forages because of its re-growth
capacity, high yield and palatability.
• leaves could be fed to growing pigs, while the
petioles are considered to be more appropriate
for feeding to pregnant sows, which need lower
levels of protein in the diet and are able to
tolerate bulky feeds as well
• The Neat Food Company, uses cocoyam to
make fufu flour
• Akwaba Food Company which exports
chopped cocoyam leaves and chips to Europe
• The young leaves and petioles which are
occasionally used for food contain about 23%
protein on a dry weight basis.
• They are also rich a source of calcium,
phosphorus, iron, Vitamin C, thiamine,
riboflavin and niacin, all of which are
important constituents of the human
• In Ghana the crop is grown on a small scale
and usually as an intercrop together with
cocoa, plantains, oil palm and cassava.
• Evidence exists that although cocoyam is
cultivated on a small scale, it has been able to
contribute significantly to the national food
baskets. They also serve as a source of income
for many families
• Xanthosoma Sagittifolium is a tropical rain forest plant
and requires an annual rainfall of about 1800mm per
• It prefers a well drained soil with pH 5.5 – 6.5
(Owueme, 1991). Although in their natural habitat they
grow under the forest canopy
• they can be cultivated in areas with full exposure to
sunlight (Owueme, 1991).
• Most tuber crops including cocoyam grow and yield
well in soils that are ploughed to a depth of about 2040cm especially on clay soils.
Cultivation of the crop
• Planting materials
• The major planting material for cocoyam is the
main stem (corm), although cormels can also be
• Selected corms are cut into pieces of about 100
to 200 grams with each piece having at least a
• For rapid field multiplication, fresh, healthy
cocoyam corms and cormels are cut into pieces of
about 5 to 10 grams (microsetts
• treated with (fungicide) and
• nursed in black polybags containing steam-sterilized
2:1 top soil: sand potting mixture
• Plantlets developed by the rapid field technique are
kept under shade for about three months before they
are planted out in their permanent fields.
• Planting materials raised from microsetts during the
dry season and planted at the onset of the rains yield
about twice more than plants grown from 100-200g
cut corms at the beginning of the rainy season (Osei,
• When cocoyams are grown in high moisture
regimes, fertilizers applied to them are
subjected to leaching and should therefore be
applied in split doses.
• The first application is done at planting whiles
the second application is done three or four
months after planting (Owueme and Sinha,
• Most farmers in tropical Africa cultivate
cocoyam without applying any chemical
• They rely mostly on the native fertility of the
soil, which is very high when virgin forest is
used to establish cocoyam.
• They may sometimes place compost or
farmyard manure in the planting holes before
HARVESTING AND STORAGE
• Cocoyam is ready for harvesting after 9-11 months
after planting. Maturity indicator for cocoyam is
yellowing of the leaves.
• For. X saggitifolium, multiple harvesting is done thus
only the cormels are removed at each harvest while
the corm is left to produce new generations of cormels,
which will be harvested latter.
• Harvesting is usually by hand or hand tools.
Alternatively the crop may be ploughed out after which
the corm and cormels are picked manually.
HARVESTING AND STORAGE
• Cocoyam can be stored for up to four months when kept
under 7oC at a relative humidity of 85% (Owueme and Sinha,
• Storage under high temperatures increases respiration,
rotting and sprouting, shortening storage life of cocoyams.
• Too low temperatures also cause corm decay (Owueme and
• Traditional storage methods include storage in underground
pits or on open platforms. Some farmers also leave the crop in
the field and harvest it as needed