Agriculture Reference
In-Depth Information
Figure 5.17. Cassava roots attached to stem. (Courtesy of the Philippines Root Crop Research
and Training Center.)
varieties contain glucosides, which have a cyano or nitrile group that is released as
cyanide, CN 2 , which is toxic. There are two generally recognized varieties of cassava,
sweet and bitter, the latter has more and former less cyano-containing glucosides.
5.6.1 Climatic Adaptation
Cassava is adapted and largely restricted to production in the humid tropics. It is com-
monly found in low-lying areas receiving high rainfall. Although it responds to
improved methods of cultivation and fertility, it is often grown on poor soil.
5.6.2 Importance in Human Nutrition
For many people in the humid tropics cassava is a staple in their diet. It can be cooked
and eaten in many of the same ways as potatoes, with the precautions noted below.
It is made into a flour that is used in baking much as wheat flour is used. Additional
information about the nutritional value of cassava is given below.
5.6.3 Propagation and Cultivation
Cassava is different from other tubers in that it is almost exclusively grown from stem
cuttings. When harvested, the tops of cassava are cut and piled for burning. During this
process a small portion of the stalk, containing at least one node, is cut off the stalk
and is planted to produce the next crop. Soil is prepared by plowing or hoeing before
planting. Initially, weeding is carried out by mechanical cultivation or by hand, but
as plants mature they shade the ground so that weeding is minimized.
As with all root crops a light soil, that is, sandy to loamy, is best for cassava. In
the case of sandy soils irrigation may be needed during dry periods, although
cassava is highly resistant to drought. Good production of cassava requires fertile
soil, which is obtained by using a field that has been fallow, use of manures, or
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