Cassava (Manihot esculenta Crantz) is one of the mandate crop of the International Institute of Tropical Agriculture (IITA) in combacting poverty and malnutrition in sub-Saharan Africa. IITA Genetic Resources Center (GRC) holds a wide spectrum of cassava germplasm ranging from wild relatives to improved varieties. There are over 3000 accessions of cassava germplasm conserved and maintained in field and in vitro bank. For best maintenance practice, the cassava field bank is regenerated every 2 years.
With the increasing climatic and environmental threats, IITA Genetic Resources Center (GRC) employ tissue culture (micropropagation) techniques in conserving endangered and rare cassava germplasm from extinction in in vitro bank. Apart from conservation, plant tissue culture (PTC) is a well known technique in rapidly producing clean (Pathogen free) and genetially identical plants. We use techniques such as meristem culture in combination with thermo-treatment of explants before in vitro culture to produce cassava plants free from pathogens. This is confirmed by the Germplasm Health Unit before conservation and distribution of cassava germplasm. Disease-free in vitro cassava plantlets can be established on the field through a postflask management technique known as acclimatization.
In ensuring good field management for cassava, a selection of good land is of utmost importance. Cassava can grow on a wide range of soils but adapts best on a well-drained, light textured, deep soils of intermediate fertility. Optimum pH is between 4.5 and 6.5 while the mean temperature is between 25-29°C. Cassava thrives well in areas with an annual well distributed rainfall of 1000-1500 mm. However, there are improved varieties that can tolerate low rainfall as low as 500 mm.
An inventory system is used to monitor the stock of cassava germplasm in the field and in vitro. Special care is also given to recalcitrant cassava germplasm in screen houses until the germplasm are able to withstand environmental conditions.