This document provides information on cocoyam (Xanthosoma saggittifolium) and cassava (Manihot esculenta). It discusses the botanical characteristics, cultivation practices, processing, uses, and nutritional value of cocoyam. For cassava, it covers varieties, ecology, production practices, fertilization, maturity, harvesting, processing, toxicities, diseases, and pests. The document is an informative guide about these two important tropical root crops.

1. COCOYAM (Xanthosoma saggittifolium)
CASSAVA (Manihot esculenta)

2. Identify the items

4. petiole
corm
cormel

5.  Cocoyam's (Colocasia and Xanthosoma spp.) are stem
tubers that are widely cultivated in both the tropical
and subtropical regions of the world.
 the two species mostly grown in West Africa are
Colocasia esculenta and Xanthosoma sagittifolium

6.  Cocoyam's can be processed into several industrial
inputs, food and feed products, similar to products
from potatoes in the Western world.
 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

7. uses
 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

8. uses
 The Neat Food Company, uses cocoyam to make fufu
flour
 Akwaba Food Company which exports chopped
cocoyam leaves and chips to Europe

9. Nutritional value
 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

10. Importance
 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

11. adaptation
 Xanthosoma Sagittifolium is a tropical rain forest plant and
requires an annual rainfall of about 1800mm per annum.
 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 20-40cm
especially on clay soils.

12. Cultivation of the crop
 Planting materials
 The major planting material for cocoyam is the main
stem (corm), although cormels can also be used.
 Selected corms are cut into pieces of about 100 to 200
grams with each piece having at least a bud
(Karikari,1971).
 For rapid field multiplication, fresh, healthy cocoyam
corms and cormels are cut into pieces of about 5 to 10
grams (microsetts


13.  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, 2003).

14. Fertilizer application
 When cocoyam's 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, 1991).

15. Fertilizer application
 Most farmers in tropical Africa cultivate cocoyam
without applying any chemical fertilizers.
 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 planting

16. 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.

17. 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, 1991).
 Storage under high temperatures increases
respiration, rotting and sprouting, shortening storage life
of cocoyam's.
 Too low temperatures also cause corm decay (Owueme and
Sinha, 1991).
 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

18. processing
 Cocoyam chips
 Cocoyam flour
 Fufu
 Chopped leaves
 dried petioles for silage

19. Cassava grater

22. Cassava (Manihot spp.)

23. CASSAVA(Manihot esculenta )

24. Varieties
 Varieties
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The following varieties are recommended for their high
yield and processing quality:
ABASA FITAA
BOSOME INSIA
TMS 30572,
NR 8082,
NR8083,
TMS 4(2) 1425,
TMS 81/00110,
TMS 92/0326. ECT

25. Varieties
 Bankehema,
 Akabon,
 suitable for fufu, gari and cassava dough and starch
 Esam Bankye also good gari, agblema and starch.

26. BOTANY

27. Ecology
 Cassava is a tropical root crop, requiring at least 8
months of warm weather to produce a crop.
 It is traditionally grown in a savanna climate, but can
be grown in extremes of rainfall.
 In moist areas it does not tolerate flooding. In
droughty areas it looses its leaves to conserve
moisture, producing new leaves when rains resume

28. Ecology
 .It takes 18 or more months to produce a crop under
adverse conditions such as cool or dry weather.
 Cassava does not tolerate freezing conditions.
 It tolerates a wide range of soil pH 4.0 to 8.0 and is
most productive in full sun.

29. Production Practices
 Cassava is planted using 7-30 cm portions of the
mature stem as propagules.
 The selection of healthy, disease-free and pest-free
propagules is essential.
 The stem cuttings are sometimes referred to as 'stakes'.
 In areas where freezing temperatures are possible.

30. Production Practices
 The cuttings are planted by hand in moist, prepared
soil, burying the lower half.
 When soils are too shallow to plant the cutting in an upright or
slanted position,
 the cutting are laid flat and covered with 2-3 cm soil
 Mechanical planters have been developed in Brazil to reduce
labor inputs.
 Typical plant spacing is 1m by 1m. Cuttings produce roots within
a few days and new shoots soon appear at old leaf petiole axes on
the stem.

31.  Botanical seeds are used only for breeding purposes.
 Early growth is relatively slow, thus weeds must be
controlled during the first few months.
 Although cassava can produce a crop with minimal
inputs, optimal yields are recorded from fields with
average soil fertility levels for food crop production
and regular moisture availability.

32. fertilization
 Responses to macro-nutrients vary, with cassava
responding most to P and K fertilization.
 High N fertilization, more than 100 kg of actual N/ha
may result in excessive foliage production at the
expense of storage root development and a low harvest
index.
 Fertilizer is only applied during the first few months of
growth.

33. Crop maturity
 Plants are ready for harvest as soon as there are storage
roots large enough to meet the requirements of the
consumer. Under the most favorable conditions, yields
of fresh roots can reach 90 t/ha while average world
yields from mostly subsistence agricultural systems are
9.8 t/ha.

34. Crop maturity
 Typically harvesting can begin as soon as eight months
after planting.
 In the tropics, plants can remain unharvested for more
than one growing season, allowing the storage roots to
enlarge further.
 However, as the roots age, the central portion
becomes woody and inedible

35. Harvesting
 Most cassava is harvested by hand, lifting the lower part of
stem and pulling the roots out of the ground, then
removing them from the base of the plant by hand.
 The upper parts of the stems with the leaves are removed
before harvest.
 Levers and ropes can be used to assist harvesting. A
mechanical harvester has been developed in Brazil. It
grabs onto the stem and lifts the roots from the
ground.

36. Harvesting
 Care must be taken during the harvesting process to
minimize damage to the roots, as this greatly reduces
shelf life.
 During the harvesting process, the cuttings for the
next crop are selected. These must be kept in a
protected location to prevent desiccation.

37. Processing

38. Toxicities
 Cassava is famous for the presence of free and bound
cyanogenic glucosides, linamarin and lotaustralin.
 They are converted to HCN in the presence of
linamarase, a naturally occurring enzyme in cassava.
 Linamarase acts on the glucosides when the cells are
ruptured. All plant parts contain cyanogenic
glucosides with the leaves having the highest
concentrations.

39. Toxicities
 In the roots, the peel has a higher concentration than
the interior. In the past, cassava was categorized as
either sweet or bitter, signifying the absence or
presence of toxic levels of cyanogenic glucosides.
 Sweet cultivars can produce as little as 20 mg of HCN
per kg of fresh roots, while bitter ones may produce
more than 50 times as much

40. DISEASES
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The diseases are;
Cassava mosaic
Bacterial blight (Xanthomonas axonopodis)
Tuber rot (Fusarium oxysporum)
Brown leaf spot (Cercosporidium henningsii)
Bacterial stem rot (Erwinia carotovora )
Anthrancnose
Armillaria root rot(shoestring root rot0
Black root and stem rot (scytalidium spp.)
Blight Leaf spot(cercospora vicosae)
Brown leaf spot(cercosporidium henningsii)

41. PEST
 The major pests are;
 Cassava mealybug (Phenacoccus manihoti)
 Cassava green spider mite complex(Mononychellus
tanajoa)
 Variegated grasshoppers(zonocerus variegatus)
 White flies(Bemissia tabaci)