|Traditional Storage of Yams and Cassave and its Improvement (GTZ)|
Cassava is a plant of tropical lowlands. Its cultivation is restricted to regions between the latitudes of 30° north and 30° south It is most widespread near the equator between 15° north and south Since cassava is a short-day plant, the highest yield of roots is in this region.
Cassava finds the most favourable growing conditions in humid-warm climates at temperatures of between 25 - 29°C and precipitations of between 1000 - 1500 mm which ideally should be evenly distributed (ONWUEME, 1978).
In view of the climate, cassava has an enormous ability to adapt. There are locations in the Andes where cassava is cultivated at an altitude of 2000 metres. Cassava can even survive slight frosts although the plant then loses its leaves which grow again when temperatures rise. Where mere are high temperature fluctuations, the annual average temperature must amount to 20°C. With low fluctuations in temperature, 17°C is also sufficient for successful cultivation (COCK, 1985).
Cassava is able to survive longer arid periods. During this period, the plant loses all its leaves and suspends growth even of the thick roots. When precipitation again begins, the plant regenerates without any great loss in yield occurring. This ability is why it is particularly suitable for locations marked by indefinite and irregular precipitation.
Cassava likes light, sandy loam soils with medium soil fertility and with good drainage. Saline, strongly alkaline and stony soils, and soils with stagnant water are unsuitable for the cultivation of cassava. Stony soils inhibit the formation of the root tuber. Where soil fertility is concerned, cassava is easily satisfied. Even on very poor and acidic soils which are totally unsuitable for the cultivation of other plants, the cassava will still provide a relatively good crop. For this reason, the cassava is frequently grown on edge locations which can otherwise not be used arably. The low demands of the cassava mean mat it is often the last member in crop rotation.