A Look at the Remarkable Cassava


 By Adriano Navarro
 Vegetable Specialist
 CVI Agricultural Experiment Station

 Of all the plants man has brought into cultivation, cassava is
undoubtedly one of the most extraordinary. Cassava has long been
known as a "supermarket" plant because all of the parts are useful.
The cassava roots or tubers provide staple food for millions of
people around the world. Cassava tubers are also an important


Full cassava plant showing leaves, main stem with leaf scars and
root system.


source of animal feed and used as raw material for the manufacture
of various industrial products. The stem is used for firewood and
fencing material, in addition to other uses, and the leaves of the
cassava make good vegetables.

 Cassava is one of the easiest plants to grow. Ease of produc-
tion is one factor which has promoted the rapid spread of the
cassava to various parts of the world. Once planted, cassava is
usually left intended until it is ready for harvest. Even if it suffers
from considerable neglect, cassava still produces the highest amount
of food per unit area of land planted -- more than any other
tropical crop.

 Another remarkable trait'of the cassava is its drought toler-
ance. There is no crop known that produces under relatively dry
conditions as many food calories per unit area per year as the
cassava. This characteristic has made cassava a popular crop in
areas of the world which have changing and uncertain climates.
Resistance to pests and its ability to give good yields on poor
soils are two other advantages of the cassava.

 As one gets familiar with the outstanding qualities of the
cassava, it would be noted that cassava comes close to being a
perfect plant for the Virgin Islands. Plant crop production in this
area has been hampered by problems such as lack of labor, uncer-
tain climate, prevalence of pests and diseases, and the lack of
water for irrigation. These production problems have also been
partially responsible for the decline of the island's agriculture.
Cassava may be one of the solutions. With cassava, there is a
chance to "green up" and turn into production once more, the
many acres of idle land in the Virgin Islands.



 THE CASSAVA PLANT

 Cassava (Manihot esculenta Crantz or Manihot utillisima
Pohl), also known as tapioca, manioc, yuca, balinghoi, or kamun-
teng kahoi, belongs to the plant family Euphorbiaceae. It is a
perennial shrub, although in agricultural production it is harvested
during the first or second year. Abandoned stands of cassava may
continue to grow for several years.

 Cassava plants may grow as high as four meters (13 ft.). The
surface of the stem may be grayish or purplish. The stem is com-
posed of the outer bark; the wood, which comprises most of the
stem; and the small area of pith at the very center of the stem.

 The leaves are palmate and spirally arranged on the stem.
Each cassava leaf tends to live only for a few months, then it is
shed. When the leaf falls, it leaves a leaf scar on the stem. Older
portions of the stem have a leaf scar at each node.

 The cassava root of commerce is a tuber with less than ten
fibrous roots of each plant becoming tuberous. Most of the fibrous
roots remain thin and continue to function in nutrient and water
absorption.

 Cassava cultivars are classified either as sweet or bitter
depending upon the amounts and distribution of prussic acid in
the tuber, a substance which is poisonous to humans. In the sweet
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