Sugar & Starch: Crops: SSCS-3
ll. A Brief Botanical Description
VI. Land Preparation
VII. Planting Requirements
VIII. Manures and Fertilizers
XIV. Harvesting and Yield
XV. Economics of Cultivation
Cassava is a tuber crop grown in few states of India. The domestic demand is not very
much but good return can be harvested by exporting it. This is because of the processed food
from it which is consumed in different forms. Besides human consumption the products and by-
products can also be used as poultry and animal feed. This booklet describes the method of
cultivation of Cassava in detail to maximize the yield per unit area.
Dr. K.T. Chandy, Agricultural & Environmental Education
Cassava (Manihot esculenta), popularly known as tapoica in India, is the most important
tuber crop cultivated in Kerala and parts of Tamil Nadu, Andhra Pradesh, Assam and
Karnataka. It is consumed both as freshly cooked tubers and processed food products like
chips and sago. It forms a component of animal and poultry feed too. Industries use tapoica for
producing starch, glucose and other food products.
Cassava is a native of tropical America from where it spread to other continents. It is
reported that the cassava crop might have been cultivated for over 4000 years in America.
Presently cassava is cultivated in all tropical regions of the world and is produced in more than
80 countries having a harvested area of about 13.0 million hectares. Africa alone covers 53%
of the total area under cassava cultivation producing about 40% of the global production.
It is believed to have been introduced in the Indian sub-continent by the Portuguese
during the early eighteenth century. India directly imported cassava from South America in
1794 and from the West Indies in 1840.
The average productivity of cassava is highest in India as compared to the world i.e. (19
tonne/hectare). The major cassava growing states are Kerala and Tamil Nadu. Other cassava
producing states are Andhra Pradesh, Karnataka, Assam, Meghalaya, Nagaland, etc.
II. A Brief Botanical Description
Cassava belongs to family Euphorbiaceae of dicotyledons. It is a perennial plant which
is raised through stem cuttings. Plant may, or may not have branching. The stem is woody and
glabrous. The leaves are spirally arranged. The petiole length of a fully opened: leaf vary from
5 to 30 centimeter. The flowering may commence as early as the sixth week after planting,
although the exact time of flower initiation depend on the cultivar and climate. Cassava is a
monoecious plant producing both male and female flowers on the same inflorescence. The
plants grown from stem cuttings produce many adventitious roots, of which a few differentiate
into tubers. Occasionally roots develop from the nodes under the soil. All the fibrous roots are
initially active in nutrient absorption but once anyone of them becomes tuberous, its ability to
absorb nutrient decreases considerably. The roots may penetrate up to a depth of 50 to 100 cm
and most of other fibrous roots remain thin and continues to function in nutrient absorption.
Cassava grows and produces best under warm, humid tropical conditions where rainfall
is well distributed and fairly abundant. It can also be grown under irrigation where rainfall is low.
In general, a well distributed annual rainfall ranging from 100 to 200 cm is considered ideal for
cassava. Its outstanding characteristic in terms of moisture requirements is the ability to
withstand fairly prolonged periods of droughts. However, at the time of planting there must be
sufficient moisture for the plant to establish itself.
The crop cannot withstand cold and is killed by frost. Cassava grows up to an altitude of
900 to 1300 m, but maximum yield are obtained from areas of medium altitude of 300 to 900
Cassava is a very adaptable plant which can tolerate a wide range of soil conditions. It
grows well in soils of low fertility status and produces satisfactory yield. Cassava grows best on
sandy loam or loamy sands while poorly drained heavy and rocky soil are unsuitable for it.
Maximum production of cassava has been reported from well drained, medium to heavy, fertile
soils with a pH value of about 5.5 to 7.0. In high textured, soil, the tubers can be harvested
easily. Cassava is sensitive to acidic soils and the yield is reduced in these soils. Newly cleared
virgin soil is also utilised for its cultivation.
The following are Cassava varieties evolved by Central Tuber Crops Research Institute,
Trivandrum which can be cultivated for different purposes.
This is a cross between a local variety Munjavelly and Brazilian variety. It is a high
yielder, giving an average yield of 35 tonnes/hectare. The conical medium sized, stout tubers
are of desirable size and brown coloured. The tubers possess white coloured flesh with
excellent cooking quality having 30.3% high starch content. This variety performs well even
under drought conditions and shows very high field resistance to cassava mosaic disease and
pests such as scale insect and red mite.
This is a hybrid variety derived from two local varieties Chandayamangalam Vella and
Kalikalan. It is a very heavy yielder giving an average tuber yield of 39 tonnes/bectare. This is
early maturing variety that can be harvested between 7.5 and 8 months after planting. Tubers
are stout conical with golden brown stem and possess 24.6% starch. Generally unbranched
plants can come up well in a spacing of 75 X 75 cm also. Hence more number of plants can be
accommodated in an unit area leading to higher yields per hectare. It has marked resistance to
cassava mosaic and is also free from attack of red mite and scale insect.
A high yielding hybrid between a local variety Ethaklea Karuppan and M-4. It gives an
average yield of 38 tonnes /hectare. It bears medium sized tubers with light brown skin. The
starchy sweet flesh is encased in a rind having light purple patches and possess good cooking
quality. The plants are branched and possess tolerant field resistance to mosaic. The plants
are also free from the attack of scale and red mite under field conditions.
4. Sri Visakham (8-1687)
It is a cross between a local variety Cheenikappa and exotic variety from Madagascar
sparsely branching type and shows field resistance to mosaic. The conical medium sized
tubers are of desirable size and are brown coloured with rough texture. The tubers are non
bitter and possess excellent cooking quality. The flesh is characteristically yellow after cooking.
The dry matter content is also 30.7 per cent. It has recorded an average yield of 44
5. Sri Sakya (8-2304)
This is a double hybrid variety. This is an erect non-branching or very sparsely
branching type. It is very vigorous and favourably responds to fertilizer application. It has a built
in potential for higher numbers of tubers of medium size. The tubers are brown and the white
flesh is encased in a creamish rind. The flesh is non- bitter in taste. This is well suited for
human consumption and for industry. The plants are very hardy and resistant to drought. It is a
long duration variety and takes about 11 months to attain the full development of tubers. It
shows high field resistance to mosaic. It has recorded an average yield of 45 tonnes/hectare.
It is an important local variety introduced from Malaya and is presently cultivated as
table variety. The plant is erect, sparsely branched at the top. The leaf is characteristically pale
green in colour. The tuber is cylindrical and the rind is purple. The flesh is non bitter. Tuber
yield is about 22 tonnes/hectare but the tubers fetch a premium price in market because of its
excellent culinary qualities.
It is an early maturing clone, well adapted to low fertility conditions. The tubers are
ready for harvest from six months onwards and preferred as a table variety due to their
excellent culinary quality. However, this clone is highly susceptible to mosaic
The plants show a spreading habit. The mature stem is grey in colour and the young
shoot is of sepia colour. The petiole has random pigmentation. It is a good yielder with about 32
tonnes hectare and the tubers are non-bitter. This clone is also susceptible to mosaic disease.
VI. Land Preparation
Proper soil manipulation prior to planting is essential to facilitate root growth. The
methods adopted for preparatory cultivation differs from place to place. In Kerala the land is
given 2 to 3 ploughing or digging pits to a depth of about 25 cm, operations involve 3 to 5
ploughing along with the incorporation of organic manures by the last ploughing.
Results showed that ploughing up to 10 and 20 cm depths in red sandy loam soil
increased the yield of cassava besides improving permeability, porosity and aggregate stability
of soil. Addition of organic manures improves the physical characteristics of the soil when
incorporated at depths of 10 and 20 cm. Square method of planting is adopted at a spacing of
90 X 90 centimeter.
Vll. Planting Requirements
Cassava is a vegetatively propagated crop. While planting, following steps should be
A. Planting stock
Cassava is normally propagated by stem cutting. Disease and insect free plant material
of 8 to 12 months maturity having a thickness of 2 to 3 cm are ideal for planting. After harvest
the cassava stems are tied into bundles and kept under storage for subsequent use. The
bundles of harvested stems with stumps, are kept in vertical position under shade in well
aerated conditions so as to protect them from direct sun rays and facilitate controlled
respiration. For short periods, these bundles are kept in suitable trenches and covered with
soil. In about 2 weeks the buds sprout and the stems are then taken out, cut into setts and
planted in the field.
Hard basal portion of the stem having more lignified tissues as well as the top tender
portion of the stem that dries up quickly are considered to be undesirable for planting.
Therefore, about 10 cm from the lower mature and about 25 -39 cm from upper immature end
is discarded. Stem length of 20 and 30 cm and planting depth of 5 cm are optimum. These
cuttings are planted horizontally, vertically or inclined at different places. About 2000 stems are
required for planting one hectare. Spraying Methyl Parathion (0.05%) or Dimethoate (0.05%)
on the stems controls scale insects.
B. Rapid multiplication
The technique of rapid multiplication of original mature planting material is based upon
the induction of sprouting of buds on the nodes of matured cassava stems. Use of a half node
stock is found to be the most efficient. The procedure for inducing sprouting is summarized
1. Stems of the desired strain, at maturity are cut into nodes as explained above.
2. A specially prepared propagating frames are taken. These frames are made from hollow
concrete block of size 4 X 15 X 10 Centimeter. While arranging these hollow blocks vertically a
frame of 1.2 X 5m is formed and kept over a 10 cm layer of crushed stones. The inside of the
frame is filled with sterile soil and hollow of the blocks is filled with water, to maintain the
3. The node cuttings are planted in the sterile soil cm deep. These produce shoots of 8 cm
length within 3 weeks. These shoots are cut and separated with a very sharp razor, leaving
behind a cm stub. The stub again grows to 8 cm shoot within four days. These are cut and
separated as mentioned above.
4. The shoot cutting of 8 cm size are put in glass jar containing aerated water. This induces in
them the sprouting and formation of roots within two weeks.
5. The shoot cutting with sprouted roots are planted in the main field.
The method and time of planting of casava is described below.
1. Method of planting
Different systems are adopted for planting cassava such as flat bed, soil-mounds and
ridge systems. In the flat system, after the land is thoroughly ploughed and harrowed. shallow
pits at the usual spacing are made and the cuttings are planted. For ridge planting, rows are
opened at the derived spacings and the setts are planted. For marking soil-mounds the ridges
are cut by narrow cross channels so as to form distinct and separate soil-mounds and the setts
are planted on the top of the soil-mounds. Very often, the soil-mounds are made directly by
heaping the loose soil with spades. It is also practised to make soil-mounds around the plants,
planted in shallow pits at a latter stage of their development. .usually the systems of planting
are related to the soil type and rainfall situation. The flat system is followed when the soil is
loose and the soil moisture is likely to become a limited factor. Where there are possibilities of
water stagnation and also where the soil tends to become compacted, the soil-mound or ridge
system is favoured. In undulating terraces and hill slopes, contour ridging is recommended to
combat soil erosion. Both the ridge and soil-mound system facilitate easy weeding and
harvesting. Under irrigated cropping, the ridge system is commonly adopted.
There are also different methods of planting the setts. The usual methods are vertical
planting, slanting or angular planting and horizontal planting. The methods used depends upon
the local agro-climatic situation. Vertical planting is adopted in heavy rainfall areas and the
slanting or angular planting in areas of moderate rainfall. The horizontal planting 5 to 10 cm
below the soil surface, is in vogue in dry climates in order to make use of the sub-soil moisture.
When planting is done in the dry season, horizontal planting is likely to lead to better
germination and to increased yield.
2. Time of planting
Normally, the planting of cassava is done with the onset of rains. But it is not strictly a
wet season crop. It can be grown almost throughout the year provided the soil is not very hard
and dry and the climate extremely hot and dry. The best time for planting cassava under
rainfed conditions in Kerala is April-May, with the beginning of the south west monsoon. In
certain areas planting is also done in September to October, taking advantage of the north east
monsoon. Gap filling should be done within 15 days after planting preferably with longer setts
of 40 cm length.
VIII. Manures and Fertilizers
The nutrient requirement of cassava is high and nutritional deficiencies are quite
widespread. Studies conducted at Central Tuber Crops Research Institute showed that for
production of about 30 tonnes of tubers per hectare about 180 -200 kg nitrogen, 15 to 22 kg
phosphorus and 140 to 160 kg potash are removed from soils. So adequate amount of
manures and fertilizers should be supplied to the field. Cattle manure or compost may be
applied @ 12.5 tonnes per hectare during the preparation of land or while filling up the pits so
as to provide about 1 kg of organic manure per plant. The fertilizer requirement depending on
the varieties are given in table
Table-I: Nutrient application to cassava
Sl. Variety Nitrogen Phosphorus Potash
No (Kg/ha) (Kg/ha) (Kg/ha)
1 H-97, H-226 75 75 75
2 H-165, H- 100 100 100
3 M-4 and local 50 50 50
Nitrogen and potash may be applied in three split doses, ie. 1/3 of the fertilizers as
basal dose, another 1/3 is applied after two months of planting and the rest 1/3 of the amount
three months after planting.
For August-September planted cassava apply half nitrogen, full phosphorus and half
potash with first digging and weeding. Remaining half nitrogen and half potash be applied 45
days after planting at the time of inter cultivation.
Intercultivation suppresses weed growth and encourages tuber formation. It is an
essential requirement for obtaining good yield from cassava fields. It is particularly important
during the first 3 months after planting when early canopy formation and root tuberization takes
place. Within 5 to 10 days after planting the planted cuttings begins to germinate and in another
2 weeks the first few leaves are formed. One intercultivation at this stage is found necessary in
most areas to control weed growth of the cassava fields. The frequency and number of
intercultivation during the subsequent stages of growth will depend on the intensity of weed
growth and the local traditions.
In India, 2 to 3 intercultivation are usually given one after 3 weeks from planting and the
subsequent ones at intervals of 3 weeks. The common methods adopted in kerala are a deep
digging or harrowing in the first month, a light digging in the second month and earthing up in
the 3rd month. In Tamil Nadu, the crop is weeded and hoed 3 to 4 times followed by earthing
up by the 4th month after planting.
In areas where rainfall is inadequate or erratic, cassava is generally grown as an
irrigated crop. In India, cassava is raised under irrigation only in some parts of Tamil Nadu.
Usually the irrigation is given on the day of planting followed by 2 irrigations at intervals of 3 to
5 days till the plants establish properly. No further irrigations are given till the end of monsoon
as the planting is usually done only after the onset of monsoon. Later, irrigation have to be
provided again at 10 to 15 days interval and, in total, 15 to 20 irrigations may be given during
the crop season depending upon the soil and the quantum and distribution of rainfall.
The most critical period of water requirement for cassava is the crop establishment
period, covering about a month from planting. Significant yield reduction occurs when cassava
plant is subjected to water stress at four to seven month of crop growth.
Cassava suffers from many diseases caused by bacteria, fungi and viruses. Some of
these major diseases with their control measures are discussed here.
1. Bacterial blight
Bacterial blight is a serious disease of cassava. This is caused by Xanthomonas
manihotis and is distributed in almost all the major cassava growing areas of tile world.
The symptom include leaf spotting and blight of leaf tissues. Wilting and die-back is
accompanied by a creamy yellow exudation from the infected parts particularly on young
shoots. Tubers of the affected plants develop black discolouration around the necrosed
vascular strands resulting in their subsequent rotting.
The recommended preventive measures are:
-Use of disease free propagating materials.
-Proper crop rotations.
-Rouging and burning of diseased plants.
-Adjustment in planting time.
2. Cassava mosaic
Cassava mosaic disease has been found to be a serious threat to the crop in India. It is
caused by virus. Usually the symptoms become manifested on the upper part of the plant
leaving the basal leaves for normal growth. The infection also causes significant reduction in
the size of all plant parts, the deve1opment of large yellowish necrotic blotches and the
deformation of leaves develop asymmetrically. The plants show a stunted appearance with
small sized, deformed leaves which are chlorotic. The colour of the chlorotic areas ranges from
pale yellow to white and in severe cases the leaves are highly curled and wrinkled with heavy
reduction in size.
Although various control measures are suggested none appears to be affective in
controlling the disease. The spread of the disease is minimized by (i) planting disease free
planting material. (ii) regular spraying with Rogar against white fly (iii) sowing resistant varieties
like H-97 and H-165 and (iv) never t2ke planting material from affected plants.
3. Brown leaf spot
This disease is caused by the fungus Cercospora lenningsii. The investigations have
shown that the disease is associated with severe leaf fall and significant reduction in tuber
The typical symptoms of the disease are the formation of dark spot on both sides of the
leaves, measuring 2 to 11 mm in diameter, depending on the conditions, which are surrounded
by a dark greyish border. On the lower surface of the leaves the spots have less distinct
margins. As the disease progresses, the central part of the spots on both the upper and lower
surfaces turns light grey in colour. The affected leaves turn brown, dry and eventually drop.
Usually the lower leaves are more susceptible than the upper leaves.
The cultural measures recommended to control the disease are removal of all infected
leaves as soon as the first symptoms are observed and destruction of all dry leaves that fall
because they serve as potential reservoir of inoculum. Spraying with Zineb a@ t 0.2 to 0.3%
has been found effective but is not profitable.
Cassava anthracnose is caused by Glomerella cingulata (Colletorichum spp), it often
appears when rain prolongs. It affects the young shoots and the growing tip die back. Leaf
spot of about 18 mm diameter are produced at the basel border of leaves and necrotic and
cancerous tissues are noticed on stem. Under south Indian conditions, the disease usually
disappears with the onset of dry season and plants regain their normal growth.
When the disease attack is severe, one or two sprayings of Dithane M-45, (0.3%) or
Bavistin (0.1%) are recommended.
5. Root rot
The root rot disease is caused by several Phytophthora species. The disease incidence
is very much favoured by poor drainage and high rainfall. Usually it appears at the beginning of
the rainy season. The symptoms of the disease are pale colouration of the leaves, sudden
wilting and a brown discolouration of the roots which eventually rot. The infection causes tissue
deterioration in developing tubers which exude a liquid with foul smell.
Improvement in the physical characteristics of the soil, use of resistant cultivars and the
adoption of closer spacing are the recommended control measures.
More than 200 species of insects and non-insect pests are reported to be associated
with cassava but only a few species cause severe damage and yield loss. These are described
1. White fly
White flies are minute insects which settle down on the under surface of the tender
leaves and suck the sap. When these occur in large numbers, they cause drooping and
yellowing of the tips of leaves. These insects act as vector for mosaic virus disease of cassava.
The adult white flies are seen in abundance at the onset of the rains. They congregate on the
under surface of tender leaves and lay very small whitish eggs. The eggs hatch out into
nymphs which crawl for some time and feed by sucking the plant sap. The white fly population
increases from July attaining maximum in October and then decline.
Foliar spray of insecticides like Rogor, Metasystox, Sevin, Folithion (0.1%) at monthly
intervals helps in reducing white fly population.
2. Red spider mite
The red spider mites are serious pests of cassava and commonly found in most of the
cassava growing areas. The adult mites are brick red in colour with two prominent spots. They
multiply quickly and aggregate on the undersurface of the leaves.
The mites begin to feed first on the lower leaves producing characteristics yellow to
reddish brown spots on the upper surface of leaves along the central vein. Eventually the
symptom spreads over the whole leaf which turns reddish brown in colour. Heavy infestation
result in blotching and bronzing of leaves followed by premature leaf fall. The very young
leaves exhibit white spots due to the loss of chlorophyll and other pigments and are very often
malformed with the margins turned upwards. With the rapid increase in mite population and
severity of attack, the growing tips can die causing excessive branching. The affected plants
become severely stunted and the yields are also reduced.
Spraying the crop thrice with Thiocron at 0.3% concentration as soon as the pest
outbreak is observed is recommended. Dusting of lime-sulphur mixture is also effective. Other
methods such as clipping the leaves at earliest infestation, rotation with other crops and
adjustment of the planting time so that the early growth stages ; do not coincide with the
summer season, are also useful.
3. Scale insect
The scale insects are serious pests of cassava which infest both the growing plants and
the stems in storage. They feed on the stem by extracting the sap with their proboscis. They
multiply rapidly and if not checked in time they cover the stems completely and cause extensive
damage by sucking their sap. A heavy infestation can result in the desiccation of the stems and
the consequent death of the plants. In early stages of infestation the plants will appear stunted
with yellowing of leaves followed by leaf fall.
-Use uninfested planting material and remove infested plant from the field.
-Spray parathion and malathion at 0.05 and 0.1% concentration to minimize the scale
In general, thrips attack the crop during dry season because rains reduce the pest
population. The thrips attack the tender leaves, shoots and buds of cassava plant. The adults
and nymphs pierce with their stylets on the undersurface of the leaves and feed on the
exudates. Consequently, the leaves are poorly developed, deformed on the margins with a
reduction in the leaf area. The leaves exhibit the characteristic symptoms of irregular elongated
chlorotic spots with imperfect development and expansion. :
Application of Dimythrote 0.03% or My thine demacron 0.025% are found to be very
effective in controlling the insects.
Termites damage the newly planted setts by making tunnels and feeding on them. The
attack appears to be severe in laterite and sandy loam soils. In the laterite soils about 20% of
the newly planted setts are usually destroyed.
Application of Aldrin or Chlordane @ 10-12 kg\hectare and dipping the setts in 0.02%
Parathion or Endrin suspension before planting effectively controls termites.
Rat is serious pest of cassava. It destroys on average about 5 to 10% of the total
production of fresh tubers in the country. They burrow into the soil and feed on the maturing
The use of traditional traps is the most popular control measure employed against them.
These traps with baits inside are kept at different points in the field. However, many of the
control measures are not effective because the rats are intelligent enough to avoid the traps
and baits. It is advisable to use non-poisoned baits for the first 3 or 4 nights to avoid bait
shyness. Several types, of rat poisons are available such as,
1. one part sodium arsenite, four part of rice polish and one part dried fish or prawn, and
2. two parts barium carbonate, four parts rice polishings and one part dried fish, prawn or bran.
In both type the ingredients are thoroughly mixed with coconut oil, made into stiff pastes and
then rolled into small balls. The balls are put inside short bamboo pieces which renders them
inaccessible to most domestic animals.
7. The Cockchafer beetle
The larvae of the cockchafer beetle which are popularly known as 'white grubs' cause
damage to the cassava plant by feeding on the roots. They live inside the soil and usually occur
in the sandy or sandy loam soil tracts. This is more serious where cassava is extensively grown
as an intercrop in coconut gardens.
Digging or ploughing in the month of May and September, when the grubs emerge on
surface in large numbers from the sub-soil will expose the pest to the attack of natural enemies
like birds, cats, dogs, etc. Application of 5% BHC or Aldrin 3% or Heptachlor at 120 kg\hectare
at the time of preparatory tillage will effectively control the pest.
Two types of intercropping system are followed with cassava.
One is intercropping with vegetables, pulses, oilseed crops and fodder in cassava field and the
other is intercropping cassava with plantations crops particularly in coconut field. Intercropping
other seasonal crops with cassava has proved to be a very efficient method for increasing the
net income from cassava field and also for improving the farm level employment potential.
It is possible to have an intercrop of groundnut during the early stages of cassava crop.
Bunch varieties like TMV -2, TMV -7, TG- 3, TG.14, and Spanish improved are preferred for
intercropping in cassava. The best season for sowing groundnut is May-June. Immediately
after planting of cassava setts, groundnut seed are sown at a spacing of 30 cm between the
rows and 20 cm within rows, so that two rows of groundnut can be accommodated between
two rows of cassava. A seed rate of 40-50 kg per hectare is recommended for dibbling one
seed per hill.
In sandy areas intercropping cassava with cowpea or blackgram or green gram may be
recommended giving a spacing of 20 cm on both sides of the ridges. The non trailing grain
cowpea variety V- 26 is recommended as a companion crop to be grown along with cassava.
XIV. Harvesting and Yield
Normally, cassava is ready for harvesting within 180 days of planting. However, a
number of factors such as rainfall, variety, etc. appear to affect the maturity period. A prolonged
drought and weed infestation are likely to retard maturity.
A rough indication of the maturity of tubers is the flowering of plants and the yellowing
and shedding of leaves. Cracking of soil surface beneath the plants is another indication that
the roots are fully developed. Another test of maturity is by breaking sample tubers collected
from a standing crop. If a medium sized tuber could be broken with both hands under moderate
force, the crop is considered mature. If it does not break easily even under great force, the crop
is considered over mature and fibrous. The depth and colour of moisture lining in the exposed
surface is also important. Proper maturity is indicated by a dry look of the exposed surface.
The common method of harvesting for cassava is by hand pulling. In loose sandy loams
and also in other soil types where the soil in soft, the whole plant is pulled out and the tubers
are collected. But when the soil is not very soft and also when large area is to be harvested, it
is a common practice to cut the stem first, leaving about 30 to 40 cm above ground to serve as
handle to pull up.
Traditional varieties produce 12 to 15 tonnes\hectare of tubers while the hybrids when
grown under ideal condition produce an average of 40 to 50 tonnes of tubers per hectare. The
average yield of local varieties of cassava is 12 to 16 tonnes per hectare.
XV. Economics of cultivation
Most of the cassava growers do not maintain farm records or accounts properly. So it is
very difficult to make out whether the enterprise is at a loss or profit. This is due to the
ignorance of proper methods of cost-benefit calculations. Given here is a format for determining
the cost benefit of cassava. From this format a farmer can choose whatever is applicable to
A. Fixed cost
1. Cost of the land Rs
2. Cost of farm structure Rs
3. Cost of fencing Rs
4. Cost of the clearing, leveling and bunding of the land Rs
5. Cost of layout Rs
6. Cost of machines, implements instruments and other accessories Rs
7. Cost of roads & paths Rs
8. Cost of permanent irrigation system Rs
9. Cost of any other permanent structure Rs
B. Recurring cost
1. Cost of fertilizers and manures Rs
2. Cost of insecticides, fungicides, weedicides, etc. Rs
3. Cost of farm power Rs
4. Transport Rs
5. Cost of farm labour (paid and unpaid) Rs
a. Cost of land preparation Rs
b. lrrigation Rs
c. Weeding Rs
d. Application of fertilizers and manures Rs
e. Application of pesticides Rs
f. Interculture operations Rs
g. Harvesting Rs
h. Processing Rs
i. Storage and marketing Rs
j. Any other labour Rs
6. Interest on fixed cost (@ 10%) Rs
7. Rent or revenue paid for)and Rs
9. Repairs and maintenance Rs
10. Crop insurance Rs
Total recurring cost Rs
1. Yield from cassava crop Rs
2. Sale of sets Rs
3. Income from intercrops Rs
Total income Rs
Net profit = Gross income -Total recurring cost
Purchase value -Junk value
Depreciation = -----------------------------------------
Note: Junk value is calculated only on those articles that are saleable after their life span. Life
span of building and machinery is 15 years and 10 years, respectively.