Cassava (Manihot esculentum) production

Area under crop:

Cassava is one of the most important crops in Nigeria. It is the most widely cultivated crop in the southern part of the country in terms of area devoted to it and number of farmers growing it. Indeed, it is grown by almost every household. Cassava has also increased in importance in the Middle Belt in recent years. In all places, cassava has become very popular as a food and cash crop and is fast replacing yam and other traditional staples of the area. Cassava is a hardy crop that is widely cultivated in the forest and savannah zones of the country. It is estimated that 5 million hectares of land is devoted to cassava annually. The annual cassava root production is about 53 million tonnes as at 2010.

Seed: Cassava stems cutting are used for cultivation of cassava roots. Seeds can be gotten from research institutes such as National Root crop Research Institutes and IITA. Cassava stems can also be obtained from other agricultural based stores.

Climatic and Soil requirements:

Cassava is very sensitive to soil water deficit during the first three months after planting, although it can withstand periods of drought. Water stress at any time in that early period reduces significantly the growth of roots and shoots, and impairs subsequent development of the storage roots. Once established, cassava can grow in areas that receive just 400 mm of average annual rainfall. But higher yields have been obtained with much higher levels of water supply. Cassava also responds well to irrigation. In trials in Nigeria, root yields increased sixfold when the quantity of water supplied by supplementary drip irrigation matched that of the season’s rainfall.

 

 

Varieties of cassava:

s/n	Original name	Outstanding characteristics
1	TMS-30572	High yielding
2	TMS-4(2)-1425	High yielding, low cyanide
3	TMS-90257	Early bulking, high yielding
4	TMS-8453	High yielding
5	TMS-82/00058	High yielding
6	TMS-82/00661	High yielding
7	TMS-81/00110	High yielding
8	TMS-30555	Moderate Yielding
9	TMS-50395	High biomass
10	TMS-30001	Moderate Yielding
11	TMS-91934	High yielding
12	TMS-419	High yielding
13	NR-8208	High yielding
14	NR-8083	High yielding
15	NR-83107	Resistant to pest and diseases
16	NR-8082	High yielding and resistant to pest and diseases
17	NR-8212	High yielding
18	NR-41044	High yielding

 

Recommended cassava varieties for different zones of Nigeria

South-Eastern states include Abia, Akwa-ibom, Anambra, Bayelsa, Cross river, Ebonyi, Enugu, Imo, Rivers	NR 8082, NR 8083, TMS 30572, TMS 30555, TMS 4(2)1425
South-western states including Delta, Edo, Ekiti, Kwara, Lagos, Ogun, Ondo, Osun, Oyo.	TMS 30572, NR 8082, NR 8083
Northern states including Adamawa, Bauchi, Benue, Borno, Gombe, Jigawa, Kaduna, Katsina, Kebbi, Kogi, Nassarawa, Niger, Plateau, Sokoto, Taraba, Yobe	TMS 30572, TMS 4(2)1425, NR 8082, NR 8083

 

 

Cultural practices/Planting method:

Stem cuttings are the main mode of propagation of cassava. Planting early in the rainy season will generally produce the highest yields because the plants have adequate soil moisture during the most critical part of their growth cycle. However, research has shown that yields may vary according to the variety used, the soil type, the plant’s age at harvest, and the rainfall intensity and distribution during any particular year. For best yield, cassava should be planted as soon as rains are established, around April in the South and June in the North. However, because most farmers give priority to other field crops, cassava is often planted late; because of high incidence of diseases, cassava should be planted as early as possible. Cuttings should be planted in a slanting position at spacing of 1mx1m. three quarter of the total length should be buried in the soil.

Nutrient deficiency symptoms:

Cassava is usually fertilized with about equal amounts of nitrogen, phosphorus and potassium. However, if the crop is grown continuously for many years, the N-P-K balance will need to be modified to compensate for the removal of nutrients, especially potassium, in the harvest. That can be done using compound fertilizers that are high in K and N, and relatively low in P.

There is also some deficiency symptoms observed but it is not possible at present to attribute them to a specific nutrient. Such symptoms include stunted growth, yellowing of leaves and scorching margin. Very rich soils do not require fertilizers but for poor or sandy soil, the fertilizer recommendations are as listed in the table below

 

 

Fertilizer recommendations for cassava

Fertility class	Nutrient	Fertilizer rate (kg/ha)	Fertilizer source
Low Medium High	N kg/ha 90 45 20	196 kg (4 bags) 98kg (2 bags) 44kg (1bag)	Urea Urea Urea
Low Medium High	P kg/ha 20 10 5	288kg (5.8 bags) 144kg (2.9 bags) 72kg (1.5 bags)	SSP SSP SSP
Low Medium High	K kg/ha 75 40 0	1.8 bags 1 bag	MOP MOP

 

Management practices

Intercropping: Grain legumes like maize make some nitrogen available to the cassava crop. In Nigeria, after two years of cassava-soybean intercropping, incorporation of soybean residues led to yield increases of 10 to 23 percent.

Alley cropping: Growing of leguminous trees with crops. Fast-growing leguminous trees may also be an effective means of improving soil fertility.

Green Manuring: Mulching legume crop residues prior to planting cassava – also improves soil fertility. Effective green manures include cowpeas, groundnuts, pigeon peas and velvet beans. Also, the use of animal manure and compost are good sources of organic matter, which improves soil structure, enhances water holding and cation exchange capacity, supplies micronutrients, and promotes the below-ground activity of earthworms, bacteria and fungi.

 

 

Weed control

HERBICIDE APPLICATION	RATE OF APPLICATION	TIME OF APPLICATION
Primetra	3.2	Pre-emergence
Gramoron + Paraquant	1.4, 2.5	Pre-emergence
Fluometeron + Paraquant	3.0, 2.5	Pre-emergence

 

Hoe weeding can be done when cassava plants are well grown above the soil. After cultivation at 15, 30, 60 and 120 days, hand-weeding has helped achieve cassava root yields of 18 tonnes per ha, only 8 percent less than those obtained when weeds were controlled with herbicides.

However, herbicides are often used on larger farms or when labour is unavailable or is too expensive. Since many products are highly toxic, farmers need to exercise care in the choice of herbicide.

 

Harvesting:

Cassava roots may be harvested at any time usually between 6 and 18 months after planting. Yield of 11-15 tonnes per hectare may be obtained under farmer’s conditions depending on management. Once harvested, roots are consumed directly by the farm household, fed to livestock or sold for processing into a wide array of value-added products. However, harvested roots deteriorate rapidly and processing must begin within 48 hours.

Also, cassava leaves can be cooked as a vegetable or used for raising silkworms as the root is not the only part of the plant that can be put to good use.

Storage:

It is best you leave cassava root still intact in the soil until you are ready to process it. Although, there are methods of storing cassava, these methods attempts to limit moisture loss from the tubers but at best they can extend the storage life of the tubers by only few days.

• Re-burying the roots in trenches covered with plant material and soil;
• Piling the roots in heaps and keeping them moist by watering them daily;
• Applying a thick coating of soft clay or mud and,
• Keeping small quantities of cassava in water.

Processing:

Once harvested, the crop can be processed into several secondary products of industrial market value. These products include: Cassava chips, Cassava pellets, Cassava flour, Cassava adhesives, Alcohol, and starch Which are vital raw materials in the livestock feed, alcohol/ethanol, textile, confectionery, wood, food and soft drinks industries. These products are also of high demand in the international market. For example the production process for garri involves:

1. Sorting:sorting out damaged or rotten cassava root and selecting the good ones for processing
2. Peeling and washing:cassava roots after selection are peeled to remove the outer brown skin and inner thick cream layer and washed to remove stains and dirt. The water source should be checked regularly to ensure it is not dirty or contaminated.

 

3. Grating: As part of the process to remove the cyanide and make the root safe to eat, the peeled cassava are grated into a mash or pulp.  Mechanized graters are needed to produce a sufficient quantity of cassava mash to meet market demands and standards.
4. De- watering and fermenting:This completes the process of removing cyanide from the cassava mash. The water content in the mash is reduced using hydraulic press. The bags are then left to drain and ferment for a few days.
5. 5. Granulating:  The cake is mechanically reduced in size to produce fine granules of greater surface area – known as grits.
6. Roasting: The grits are then roasted or fried in a hot frying tray or pan to form the final dry and crispy product.
7. Sieving: The Gari is sieved to separate coarse particles, with a standard size sieve to produce fine granules. A grinder is used to break the large granules into smaller ones.
8. Packaging: Garri is weighed and then packed for marketing.

 

Marketing:

Human beings

People buy cassava and process them into garri, chips, and other byproducts.

 

 

Animal Feed Producers

Cassava peels are now being sold to animal feed producers to make feeds for their livestock such as goat, fishes etc.

Industrial consumers

Some of the biggest industrial buyers of cassava are food producers and breweries. Breweries make use of cassava as a major raw material for beer production. Africans consume millions of litres of beer every year and this volume is expected to rise significantly due to population growth and economic prosperity. The more beer is produced, the more cassava that will be purchased by brewers across the continent.