Cassava : Manihot esculenta

Cassava (Manihot esculenta) which belongs to the family Euphorbiaceae is a robust productive starchy root crop that is grown clonally almost entirely within the tropics, grown chiefly as a food. But it is also an important animal feed, and it has several significant industrial uses. Cassava is a perennial crop, originated in Brazil with Central America and introduced to Sri Lanka in the Dutch regime. Since then cassava stands out in the country as the most important source of energy for the calorie deficient low-income population strata. But from the recent past it has now become a major horticultural export commodity earning foreign exchange.


Nutritional Value

Cassava roots combine high energy and high levels of some vitamins, minerals and dictary fiber and contain no trypsin inhibitor, but create a problem due to presence of cyanide which is removed by post-harvest treatments and cooking. The edible green leaves of cassava are a good source of protein, vitamins and minerals and are often used to augment the rural diet.


Nutritional values of Cassava

Component

Root tubers

Leaves

Moisture %
Energy (Kg/100g)
Protein %
Starch %
Sugar %
Dietary fiber %
Ash %

62.8
580
0.53
31.0
0.83
1.40
0.84

74.8
-
5.1
-
-
-
2.7

Minerals (mg/100g)
Ca
P
Mg
K
S
Fe

20
46
30
302
6.4
0.23

350
56
-
-
-
218

Vitamins (mg/100g)
Vit. A
Thiamin
Riboflavin
Nicotinic acid
Vit. C

Trace
0.05
0.04
0.6
15.0

3
0.2
0.3
1.5
200

Source: Bradbury and Holloway, 1988


Growing situations

Although cassava is not a nutritionally superior crop, from the agricultural point of view its popularity among resource poor farmers is due to its remarkable hardiness, drought resistance, relative freedom from pest attack and its ability to give acceptable yields under unfavoured conditions with low inputs and attention. It is mainly grown as a rain fed crop throughout the island excluding high elevation areas and mostly concentrating in the wet and intermediate zones. The production systems of cassava have been identified as a backyard crop and large scale open-land cultivation in the wet zone (Gampaha, Colombo, Kegalle, Rathnapura and Matara Districts) as well as in the intermediate zone (Kurunegala district) are mixed cropped with coconut and pineapple cultivations. Chena cultivation in large scale in the dry zone (Putlam, Anuradhapura, Ampara, Hambantota, Moneragala Districts) is viable. Peak production falls during Maha season.

Recommended Varieties

Three improved cassava varieties namely MU-51 (var. Peradeniya), CARI-555 and Kirikawadi having high yield and acceptable horticultural qualities have been recommended for cultivation. Besides these 3 varieties there are few farmer's selections with better consumer acceptance that are being cultivated

Crop Management

Fertilizer Application

 

Urea

TSP

MOP

Basal

80       

120

80

TP-1

80

--- 

80

TP-3

80

---

80


Basal 10 to 12 days after planting
Top Dressing -1 6 to 8 Weeks after planting
Top Dressing -2 14 to16 Weeks after planting

Pest
Scale Insects
White fly
Mealy bug

Diseases
CMV virus
Circuspore Leaf spot