WHAT IS CASSAVA(Manihot spp)
Cassava just like yam, is a root and tuber crop. It has underground roots which can be consumed by man and livestock animals after processing. It has other advantages over yam, in that it can grow in relatively poor soil and in low rainfall area. The root is also rich in carbohydrates.
The tubers (root tubers, tuberous roots, storage roots) are true roots modified to function only as storage organs that cannot absorb
water or plant nutrients from the soil and cannot be used for vegetative propagation or as planting material.
The older root tubers become lignified.
The mature cassava storage root has 3 distinct tissues:
Land Preparation of Cassava
Varieties/Cultivars of Cassava
There exist two main varieties: sweet cassava (Manihot palmata) and bitter cassava (Manihot utilissima). The latter contains some poisonous hydrocyanic acid in its root.
Climatic and soil requirement for cassava cultivation
Cassava requires a temperature of 21C – 35C, rainfall of 150cm – 200cm, a well-drained, rich, friable,loamy soil. It can also grow m poor soil. A good size for a cassava garden is 10 m long and 2 m wide, with 32 cassava plants, 60 × 120 cm apart.
The ground should be dug well twice.
Double digging is needed to make the soil soft and to kill the weeds.
Ask a field officer of the Ministry of Agriculture to recommend a suitable variety for the cassava project.
A light sandy soil best with good drainage but almost any soil type can be used except salty or waterlogged soils.
Good yields can be obtained on heavily cropped soils so cassava is suitable as the last crop in a rotation.
During drought cassava stops growing and drops its leaves but it usually recovers well after new rain.
Cassava is a shrub to about 1-3m, thin stems, large palm-shaped leaves, with high yield of tuberous roots, the main part that is eaten,
but also leaves as edible vegetables. A most productive use of subsistence land, but all cassava is poisonous containing hydrocyanic acid, with the more toxic varieties
However, thorough cooking denatures the harmful toxins to make it safe to eat.
Method of Cassava propagation :
By stem cuttings which are planted from March to September.
Planting date for cassava:
Cassava sticks or cuttings are planted from March to September.
Planting date: Cassava sticks or cuttings are planted from March to September
how to Space cassava:
Cassava is spaced 1m by 1m
Planting methods for cassava :
A stem cutting of 25 – 30cm long is pushed into the ridge or heap slanty at an angle of45°and C of it buried. Sprouting occurs 7- 14 days later.
Cultural Practices in cassava cultivation
Classification of Cassava plant
Cassava is a perennial, but cultivated as an annual crop, woody shrub with latex in all parts, 1 to 6 m in height.
Many varieties and cultivars exist but most are cultigens, i.e. known only as cultivated forms.
The bitter and sweet varieties of cassavas were formerly separate species, Manihot esculenta the bitter cassava and Manihot
palmata the sweet cassava.
However, the bitterness depends on many factors including soil, climate and location so now cassavas are informally divided into bitter
and sweet types and sometimes into short season and long season cultivars.
Also, cassava formerly had the scientific name Manihot utilissima.
Nowadays all varieties and cultivars of cassava have the same scientific name, Manihot esculenta..
Maturity Period of cassava :
This occurs between 8 – 15months depending on varieties/
Cassava Harvesting process:
Use cutlass to remove some soil and pull the stem gently so that the tubers are pulled along or, use cassava puller.
Cassava Processing :
Cassava is processed into garri, foo foo, flour or livestock feed.
Storage: Cassava is stored in processed form in sack as garri (cassava flour or foo foo).
importance of cassava
Cassava is an important source of starchy food in tropical regions.
Its cultivation needs little labour input so it is cheap to produce.
Cassava is a benchmark for food security because it is affordable by the poor.
Pest of Cassava and control methods
(1) Variegated Grasshopper: Adults and nymphs eat up the leaves and young and eat up the tubers.
(ii) Shooting with gun
(iii) Wire fencing round the farm
origin of cassava
Cassava has the scientific name, Manihot esculenta and is in the Family Euphorbiaceae, the spruce family, which includes natural rubber
(Hevea brasiliensis) castor oil (Ricinus comunis) and ornamentals, e.g. poinsettia (Euphorbia sp.).
Latex occurs in all parts of the plant and a related species Manihot glaziovii was formerly used in commercial rubber plantations to make rubber.
Most varieties of cassava are diploid with 2n chromosome number = 36.
Diseases of Cassava and control methods
Cassava mosaic disease :
It is caused by virus which is transmitted by a piercing and sucking insect (white flies).
Symptoms include vein clearing and distortion of the leaves and stunted plants
(i) Grow resistant varieties
(ii) Uproot and burn infected plants
(iii) Use disease free planting materials
Bacteria blight of cassava :
It is caused by bacteria which are transmitted by infected cuttings.
These include angular, water- soaked area of discoloured leaf tissue, blighting, wilting and reduction in yield.
(i) Use resistant varieties
(ii) Use lean and disease-free stem cuttings
Angular leaf spot of cassava:
It is caused by a fungus.
Symptoms: include spores which produce pale, brownish colour on affected leaves.
(i) Spray with fungicide, e.g. Bordeaux mixture.
HERE YOU WILL FIND EVERY AVAILABLE TOPICS ABOUT AGRICULTURAL SCIENCE AND BIOLOGY. AND THE LINKS TO THEIR VARIOUS SOURCES.
1. DEVELOPMENT OF AGRICULTURE
2. IMPORTANCE OF AGRICULTURE
40. SOCIAL-ECONOMIC FACTORS
41. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
42. CLIMATIC FACTORS AFFECTING AGRICULTURAL PRODUCTION
47. SOLAR RADIATION
48. BIOTIC FACTOR AND AGRICULTURAL PRODUCTION
52. SOIL MICRO-ORGANISMS
53. SOIL PH
54. ROCK FORMATION
55. IGNEOUS ROCK
56. SEDIMENTARY ROCKS
58. SOIL AND ITS FORMATION
59. FACTORS OF SOIL FORMATION