Cassava (Manihot esculenta Crantz) provides more than 800 million people in Africa, Asia and Latin America with food, nutrition, and livelihoods. In Nigeria, cassava provides more than 80% of the daily caloric requirements for more than 50% of the population. Farmers also generate income by marketing both fresh storage roots and processed products. Yellow root color cassava contains an elevated amount of provitamin A carotenoids. Cassava, therefore, has great potential for combating poverty as well as food and nutritional insecurity.
Potentially limiting, cassava roots have a very short shelf life. This is because post-harvest physiological deterioration (PPD) is rapid, beginning within 24 to 48 hours after harvest, and can result in losses in the range of 40–60% of the total expected economic value of the crop. Techniques currently used to delay PPD such as vacuum packing are not practical in developing countries.
PPD can be separated into two stages of deterioration: primary and secondary. Primary deterioration starts from the central vascular bundles of the root, spreads to the adjacent storage parenchyma and subsequently stored starch undergoes structural changes. The visible signs of primary deterioration are vascular streaking with a blue or black discoloration that renders the roots unpalatable and unmarketable. This initial deterioration is physiological and biochemical. Secondary deterioration is due to infection with microorganisms, leading to fermentation and softening of the root tissue. Primary deterioration is more important economically than secondary deterioration because the visible coloration of the root is used as an indication of its cooking quality.
In collaboration with Njoku Damian Ndubuisi at the National Root Crops Research Institute (NRCRI) Umudike in Umuahia, Nigeria, we are developing high provitamin A, PPD tolerant cassava lines adapted to Nigeria via genomic selection to reduce root losses and improve the nutritional and economic value of this staple crop.
Funding: BMGF PEARL OPP1112564.