CASSAVA PROGRAMME
Cassava (Manihot
esculenta): It is a staple
food crop in many parts of the tropics and it is capable of producing high
yield under condition of poor soil fertility and rainfall. It is also known as
tapioca. It is also an important component of traditional cropping system.
ORIGIN
Cassava
originated in part of Central America it was introduce to West Africa by the
Portugus in 16th Centenary.
This is an I.T Report on Agriculture
BOTANY OF
CASSAVA:
It
is a short – lived dicotyledonous shrub which grows to a height of 1 – 5m with
later in all parts, the root comprise tuber which develops as a swollen on
advantageous root, a short distance from the stem by a process of secondary
tuckering once a tuber becomes tuberous, it no longer participate actively in
the absorption of water and mineral salt. Starch accumulation in the tuberous
cassava root commence near it point of attachment to the stem and progresses
towards the distance portion of fastest near it point of attachment to the stem
and tapper gradually toward the distance portion.
The
tuber is attached to the stem by a stout wood neck. The number, shape, size
angle at which they penetrate the ground, colour of outer cock and internal
tissue varies greatly among different cultures.
Cassava
tubers vary between 5 – 10 per plant and they are either cylindrical or
tapping. 15 – 100cm long and 3 – 25cm across, the tuber consist of outer
(peridem) the ring or Core and core (pith).
In addition to the tuber, fibrous
adventitious root develop horizontally and vertically which are active in the
absorption of water and mineral salt. The stem varies greatly in height and
branching habit. Branching near the base in some cultures, high up in other;
the angle of branching with the main stem determines whether plants are erect
or branching.
Cassava plant is a common root crop
that matures between 8 – 9 month depending on the variety or species planted.
Cassava is like any other plant, it has leaves, stem and the root.
There are three
parts of cassava that are very useful to humans.
1. The leaf is a very good source of
vegetable
2. Stem is sold to other farmers for
planting
3. Root is processed to various finished
products for human consumption.
The leave are spirally arranged the
petiole 5 - 30cm long, usually deeply palmate divided with 3 – 9 lobes usually
5 – 7 and numbers may vary on the same plant, lower leaves term to have more
than upper leaves. Some cultures have reddish colour petioles and varies which
in orders they are green. The flowers are unisexual with male and female
flowers in the same inflorescence the cater near the base. Female flowers are
usually bigger than male flowers; male flower opens 7 -8 days after the female
(protogynous) and so if is cross pollinated. Many of the varieties now in
cultivation rarely flower.
The cassava fruit is a spherical
capsule about 1.5cm long, glabrous with narrow longitude wing – like structure
in the outside, three seeded, wooden endocarp.
Splitting
explosively on ripening 3 – 5 months after pollinating and ejecting seeds the
seeds are about 12mm long, gray mottled with Clark blotches.
CULTIVATORS:
Many
varieties of cassava are cultivated in Nigeria; most of the currently
recommended varieties grown in Nigeria were released by IITA
Ibadan and NRCRI Umudike Umuhia,
There are TMS or NR series respectively. Many varieties can be differentiated
by morphological characteristics such as leaf size, colour and shape, branching
habit, plant height, colour time of maturity and yield.
LAND
ACQUISITION/SELECTION
Land
can be acquired by purchase to own it, or for a year, two or the number of
years you intend to use it. The site for cassava cultivation should be selected
to be a well drained fertile soil that is accessible.
WHEN TO PLANT
CASSAVA
Cassava
planting has no rigid time of plant, it is advisable to plant when the rainy
season is about to end or the dry season is about setting in. This depends on
the weather or season in your area.
LAND PREPARATION
Land preparation
can be treated under two ways:
i. Mechanized way of land preparation
ii. Traditional or local way of land
preparation.
MECHANIZED WAY
OF LAND PREPARATION
This
involves the use of heavy equipment such as bulldozer, tractors etc. The mode
of operation, the bulldozer is used to remove the big trees i.e. open up the
lands, and pack the entre stomp and the wood to side of the farm and allow to
fallow for about two months. Thereafter, tractor is used to plough and harrow
the land before ploughing and harrowing per – land preparation weed control are
used at rate of 4 – 5 liter/h.
TRADITIONAL OR
LOCAL WAY OF LAND PREPARATION
In
this method, do it the way it is done in your place. For example, in Imo state,
land preparation for cassava is very easy. The select farm area is brushed by
casual laborer; it is all owed to stay for about two weeks to allow the cut
down plants to try properly. At the end of the 14th day, between the
periods of 3.30 – 4.30pm they will go the end set fire and ensure the farm is
thoroughly burnt.
CASSAVA CAN BE
GROUPED INTO TWO LARGE SPECIES
i. Bitter
ii. Sweet varieties
This
classification is according to HCN level (hydrocyanic acid)
Better
cassavas have higher HCN content and the HCN are usually destructed throughout
the tuber.
·
Sweet
cassava with low HCN conforms to the outer skin (periden) cassavas are also
classified according to HCN content. In terms of HCN content per 100g fresh
weight to give three groups as follow:
1. Cassava with low HCN content: less than
5mg/100g fresh weight of ten concentrations in the peal e.g. TMS 4(2)1425 and
TMS 30555
2. Cassava with intermediate level of HCN
in which the level range between 5 -10mg/100g fresh weight e.g. TMS 30572, TMS
30555.
3. Cassava with HCN content: 10mg/100g
fresh weight or more. E.g. Tms 50395.
CLASSIFICATION
OF CASSAVA ACCORDING TO MATURITY DATE
1. Short season varieties (early maturing)
which mature as early as 6months after and can be left in the ground longer
than 9 – 11 months without serious discoloration, these cassavas sweet.
2. Long season varieties (late maturing)
takes cutlass a year or more and can be left in the ground for 3 – 4 years
without serious.
CLIMATIC AND
SOIL REQUIREMENT:
The
crop is widely cultivated from the mangrove swarm in Nigeria dealt to the
savannahs; it can operate a long period of draught when it shell it leaves and
come up quickly when there is rain. It is extremely prone to excessive flooding, it requires warm temperature, high
rainfall that most exceed 750ml, it can be grown in almost all soil types
provided they are not water logged to shallow, stony or heavy (clay soil) it
grow best in sandy or sandy – loamy soil of reasonable fertility. It can also
tolerate poor soil and will give economically adequate yields on soil that are
too poor for other crops such as maize, yam, plantain and leafy vegetable.
CULTURAL
PRACTICES
1. PRODUCTION
SYSTEM: Cassava can be planted on mound ridges on the flat after ploughing
in most traditional cropping system (production system) cassava is inter planted
with cereals such as maize and rice or legumes such as soya beans millet in the
first 3 months after planting.
2. METHOD
OF PROPAGATION: The main method of propagation in by stem cutting
propagation by seeds in confired to breeding work cultivars readily take off
and produce fibrous adventitious root system which becomes very extremely
developed both laterally and vertically. Cutting should at least be 25cm long
and planted in a starting position or buried at a spacing of 1m by 1m. Sweet
cassava may be planted closely at 0.75m to 1.00m. The cuttings must be treated
with Adres 40 of termites are present.
3. TIME
OF PROPAGATION: Cassava should be planted as soon as rainfall established
around April in South and June in the North.
CASSAVA
VARIETIES
There
are numerous cassava varieties exist in each zone where the crops grown. There
are about 2,200 different varieties of cassava in (NRCRI). Examples of cassava
varieties NR 8082, NR 8086, TMS 05051, TMS 419, TMS 2205, TMS 84292, TMS, 8410,
TMS 84104, TMS 1080, TMS 98/058/, TMS 97/2205
QUALITY OF
CASSAVA STEM FOR PLANTING
The
ideal cassava stem for planting should have the following qualities:
i. The cassava stem should be allowed to
stay for at least one week before use for planting after cutting.
ii. The planting length should be in
between 25 – 50cm long a very long stem and short stem is not good for
planting.
iii. Use cutlass to cut the cassava stem for
planting and it should produce a whitish liquid substance, to indicate that the
cassava stems viable for planting.
METHOD OF
PLANTING CASSAVA
The
planting distance is (1 x 1)m it could be planted in a role zigzag form,
depending on your planting choice. The cutting of 2.0 – 3.0 diameter should not
be laid horizontally or vertically, but be tinted or slanted at an angle or 10
– 20. The older part of the stem should be the part that is deeper in the soil
than the younger part. The stem should be completely covered with soil or small
part or the top open.
PLANTING STYLE
CROP MAINTENANCE
1. WEED
CONTROL:
A. Manually: two – three manual weeding
within the first 3 months is very important for good field establishment.
B. Chemical: uses of perimeter at the rate
of 3gai applied/emergence. If weeds are already present after planting
perimeter can be mixed with round up (city phosphate)
C. Culturally: Dense plant population and
the use of low branching varieties promote early closing a canopy and checking
of weed growth.
2. FERTILIZER
APPLICATION:
I
participated in applying NPK 20:10:10 to the cassava by the recommended side
band application method. Although cassava tolerates poor soils, increased tuber
yields are obtained with fertilizer application, particularly where cassava is
cropped continuously. As a heavy feeder, on per crop basis, cassava extracts
more nutrients from the soil than most tropical crops. It extracts more K than
other crops. It also extracts large amounts of N while the extraction of P and
mg is relative low.
According to Prevott (1958), cassava has
the highest K/N extraction ration. This underscores the need to have high
levels of K and N in the fertilizer formulation for cassava production.
Excessive
nitrogen leads to vegetative growth at the expense of root-tuber production.
Therefore, a proper balance of N should be the goal. It is therefore recommended
that soil analysis be carried out to determine the nutrient status of the field
before sourcing for fertilizers. The inclusion of adequate amount of micro
nutrient is also important, since absence of some micronutrient in cassava
nutrient causes about 30% reduction in cassava yield (Mortvedt, 1985).
Additionally,
plant tissue analysis may also serve as an indicator of the nutritional status
of the plant.
Highlights of
Good Fertilizer Policy
A good fertilizer policy for minimum
cassava production should be arrived at after due consideration of the
following:
·
Data
from soil analysis
·
Effects
of soil type and texture
·
The
previous cropping and residues
·
The
rainfall regime
·
Land
tenure systems
·
The
purpose for which the crop is grown
·
The
amounts required
·
Choice
of type of fertilizer to be used
·
The
method of application, manual or mechanical
·
Time
of application
·
The
cost of the fertilizer vis-Ã -vis economic returns
Recommended
Fertilizer Types/Rates (Kg/Ha)
·
NPK:
20:10:10:2S:1Zn at the rate of 400 – 600kg/ha
·
NPK: 12:12:17:2Mg
at the rate of 400 – 600kg/ha
The
rate of application depends on:
·
Nature
of soil
·
Previous
cropping history
·
Plant
density
·
The
cultivar in use
The method of application was by band
placement or ring application and the time of application depends on crop
performance but preferably any time from 8weeks. At this period, tuber
initiation has taken place and the carbohydrate reserve in the stem cutting
would have been exhausted. In other words, sink source relationships are quite
in place.
In some plots where poultry manure were
made readily available, 200kg NPK plus 2000-4000kg poultry manure was applied
per hectare. For ease of application, that poultry manure was incorporated into
the soil at the time of land preparation followed by the application of NPK at
8weeks after crop establishment. Where the pH value is less than 4.0, lime was
applied at the rate of 1000-1,500kg/ha.
Identified pest
at the cassava farm
1. Grasshoppers
– Zonocerus variegates
2. Mites
– Tetranychus spp. (Red mite)
-
Monoychelius spp. (cassava green mite)
3. Cassava
mealy Bug – Phenacocus Manihoti
4. Termites
– coptolermes spp.
PEST AND DISEASE CONTROL ON CASSAVA TUBER
a. Use
of clean planting material
b. Use
of resistant varieties
c. Plant
at the right time
d. Avoidance
of infested site
e. Insecticidal
spray such as vector 85 sketching applied at 2kg effectively control meanly
bug, spider mites and grass hoppers.
SYMPTOMS OF DISEASES ON CASSAVA
·
Yellow
green mosaic
·
Whitish
·
Various
degree of deformation/distortion
·
Stunted
growth usually between 6 – 14 weeks
Diseases
that attack the cassava
CONTROL OF PESTS AND DISEASES OF CASSAVA
Field inspection should be conducted
during the rainy season on plant that is 6 – 14 weeks old. Cutting for planting
should be inspected before use.
HARVESTING OF CASSAVA
Cassava is harvested at 9 month for early
maturing varieties and 1 – 1 quarter years for late varieties. Harvesting is
done manually by and pulling of tubers from the soil, digging may be necessary
for easy of pulling.
Harvested tuber should be process
immediately or buried in the ground temporary as fermentation is rapid.
YIELD OF CASSAVA
In some crop, yield may vary between 10
– 40 tones per hectare. Under more intensive management and proper fertility. A
yield of 70 tones per hectare could be obtained.
STORAGE OF CASSAVA TUBERS
First tubers do not keep well beyond 24
hours restricted harvesting is recommended to the quantity that can be
processed or sold out.
Tubers can be processed into Flour,
Garri, Cassavita, Akpu, Starch, Chips.
USES OF CASSAVA
INDUSTRIAL
USES:
Cassava starch is used in laundry and
manufacturing many product such as beer and other alcoholic drinks. Cassava
flour can be used to replace wheat in baking powder for bread, biscuit and cake
making.
CASSAVA
PRODUCTS
Cassava root being the major source of
raw materials to several products, as explained in the diagram below can be
processed in several ways for different uses.
MATERIALS
USED FOR POLLINATION AT THE INSTITUTE
Sieved bags that measured 20cm x 25cm
were used to protect flowers from undesired pollen. Small sieve bags that
measured 10cm x 18cm were used to collect the matured seeds. The bags were made
of cotton material of 60 to 80 meshes and had a string attached to close its
mouth on the plant. tags of 3cm x 4cm were used to label pollinated flowers
(necessary for data collection). Bottles of 3 to 5cm in diameter and 5 to 8cm
high were used to carry male flowers during pollination.
CASSAVA
POLLINATION PROCEDURE
·
The
method used at Umudike is called hybridization (cross breeding)
·
Mature
male and female flowers were identified prior to pollination.
·
The
mature female flowers (gynoecium) were covered with the sieved bags in the
morning to enhance the opening of their petals before noon and also prevent
other pollinating agents like bees from pollination the flowers.
·
The
desired male flowers (androecia) were collected and carried in bags.
·
The
above 2 steps were done in the morning, between 7:00am and 9:00am before the
sun started to rise.
·
The
pollination was done in the noon between 1:00pm and 5:00pm before sunset (to
pollinate, the bag used to cover flower, the androecia was burst open and its
pollen rubbed properly on the stigma of the gynaecium).
·
Having
completed pollination, the gynaeciums so pollinated were covered with the bags.
·
Each
flower branch on which the pollination was made, was made, was labeled with a
lay indicating the cross combination, date of pollination and number of
gyaecium pollinated.
3. DATA COLLECTION: Data collection is a
very critical and important aspect of cassava breeding as lack of such at any
stage of the research may adversely affect the research or even nullify the
authenticity of labourers and potted bags per day (for calculation of man days,
cost of production etc); date of planting sowing, number of seeds sown per day
date of germination, date of transplanting to the field.
SOIL SCIENCE LABORATORY ACTIVITIES
The activities performed in the soil
science laboratory of the National Root Crops Research Institute Umudike.
Characteristics
of soils which includes:
1.
Organic
matter/carbon
2.
Available
phosphorous
3.
Total
Nitrogen
4.
Total
exchangeable bases (TEB) (Cu, Mg, K, Na)
5.
Exchangeable
acidity (Al+ + H+)
6.
Effective
cation exchange capacity.
Analysis
of fertilizer and plant samples
1.
Nitrogen
(N)
2.
Phosphorous
(P)
3.
Potassium
(K)
APPARATUS/EQUIPMENTS
IN THE LABORATORY AND THEIR USES
1. FUME
CUPBOARD: This is used for heating poisonous chemical/samples and for
digesting some samples to avoid the dangerous odour from the samples from
polluting the environment.
2. MILLING
MACHINE: This is used in milling plant/food materials like leaves, roots,
grains etc. This is to ensure homogeneity, intimate chemical reaction and
mutual chemical interaction.
3. WATER
BATH: this is used for mixing soil samples for particle size distribution.
4. PH
METER: This is used for taking the reading of PH of samples. The most
essential part of this machine is the electrode.
5. SPECTROPHOTOMETER:
This is used in advanced chemical analysis for detecting the presence of
solution e.g. determination of available phosphorous and heavy metals.
6. SENSITIVE
ANALYTICAL BALANCE: This is used for taking the weight of samples.
7. MUFFLE
FURNACE: It is used for heating plant materials e.g. root, leaves etc up to
800oc.
8. MECHANICAL
SHAKERS: This is used to shake samples to a required hour for nutrient or
minerals extraction from the soil, plant, water or food samples.
9. DRY
OVER: This is used in drying glass wares, leave samples, grains and some
reagents. It has an inbuilt thermostat.
Others
are:
Volumetric
flasks, standard flasks, conical flasks, beakers, forcepts plastic rubber
turbine, (bottles) automatic burette crucibles, pipette, measuring cylinder,
soil hydrometer, plungers, dissicastor, spatulas etc.
PARTICLES SIZE
DISTRIBUTION (MECHANICAL ANALYSIS)
APPARATUS
·
Sedimentation
cylinder
·
Motor
stirrer and cup
·
Bouycous
hydrometer
·
Special
stirring peddle
·
Stop
watch
·
Funnel
10 – 12cm diameter
·
Wash
bottler (Plastic)
·
Balance
accurate to 10mg
·
Percolation
basing
·
Desiccation.
REAGENTS
i. Sodium hexametaphosphate (Na2PO3)b and Sodium Carbonate Na2 Co3.
These two reagents are called Calgon solution or dispersing solution.
The calgon solution is prepared by
dissolving 35.7g dry powdered sodium hexametaphospate and 7.94g anhydrous
sodium carbonate to 1 liter.
Dissolve the (Na2PO3)6
first by adding the dry powder slowly to about 750ml water which is well stored
during the addition. Then add the sodium carbonate and make up to one (1)
liter, this solution contains 0.35N (Na2
Po3)6 and 0.5N (Na2Co3) = 0.5N Na+10N.
ii. Hydrogen Peroxide 30% 100 volume.
PROCEDURE
The
Bouycous hydrometer method for particles size distribution follows the
procedures:
·
Weigh
out 50g of the prepared soil sample and transfer to a cup of mechanical
stirrer.
·
Add
50ml of calgon solution and allow it to stay for 24 hours for complete
separation.
·
Stir
very well using plunger for 2 – 10 minutes depending on soil and then wash down
the stirring blades as they are removed from suspension.
·
Read
the temperature using thermometers. The temperature should be between 15oc and 25oc.
·
Mix
with special plunger and start timing.
·
Take
the first reading (silt + clay) after 40 seconds of timing. At the completion
of the 40 seconds the bouycous hydrometer careful into the center of the
suspension and release it gentle so that it does not rotate nor move up or down
to violently. Take the reading on the scale to the nearest 0.5 unit.
·
Take
another reading for clay after 2 hours.
·
Finally,
obtain a blank reading by preparing 1 liter of 0.5% calgon solution (dilute the
stock solution ten times) and adjust the temperature to 20oc.
·
Insert
a bouycous hydrometer and take the reading.
This is an I.T Report on Agriculture