Orange fleshed cassava a real deal

Saturday March 16 2019

Dr William Esuma (right) checks the new

Dr William Esuma (right) checks the new variety. photo by lominda afedraru 

By Lominda Afedraru

The common talk in the country in as far as enriched crops with vitamin and Iron nutrient is concerned is about the orange fleshed sweet potato which agricultural scientists at the National Agriculture Research Organisation (Naro) have been promoting across the country.
However this is no longer the case because scientists breeding cassava at the National Crop Resources Research Institute (NaCRRI) in Namulonge have been breeding orange fleshed cassava enriching it with vitamin A, Iron, Zinc and other micro nutrients to help solve the challenge of nutrient deficiency in the population consuming cassava as their staple food.
The target is mainly children and pregnant mothers, who usually are in dire need of these food nutrients instead of taking costly tablets.
Dr William Esuma, the head of the bio - fortification breeding initiative at NaCCRI, talked to Seeds of Gold about this product innovation.

How it all started
Dr Esuma explains that his team took a scientific survey across all regions growing cassava as a staple food in the country and realised they are basically consuming starch and water, which apparently, are the food nutrients in white cassava varieties.
To him, it is important to incorporate food nutrients such as protein and other related micro nutrients such as sodium, potassium, magnesium and other vitamin components, a case in point Vitamin B 1, which helps in converting nutrients into energy.
As such, 15 years ago, there was a global initiative to improve nutrition in food and scientists came up with the initiative of breeding bio fortified plants.
In Uganda one of them is the Bio fortified transgenic sweet banana and cooking banana as well as the orange fleshed sweet potato.
The NaCRRI team under the Next Generation cassava breeding initiative funded by Bill and Melinda Gates is part of a large project where scientists are also breeding against cassava brown streak virus disease (CBSV) and cassava mosaic virus disease (CMV) across the continent.
The breeding initiative for beta carotene cassava started in 2009 with the major objective to attain vitamin A which provides better visual characteristics for people who are challenged and to provide immunity for children and pregnant mothers.

The breeding process
Dr Esuma and team obtained yellow fleshed cassava varieties from Latin America particularly Brazil and Colombia where cassava originates. The varieties were planted in fields at the institute.
After maturity, the breeders picked pollen from the yellow fleshed cassava varieties which were crossed to the traditional farmer preferred varieties here.
The team has generated cassava varieties with root tubers which are yellowish in colour, not completely yellow because the crossing is done between yellow fleshed and white fleshed cassava varieties.
The generated varieties contain 50 per cent beta carotene food value. According to Dr Esuma the white cassava root tuber contains 80 per cent starch and 20 per cent water.
These varieties have been tested for disease tolerance at the field in Namulonge and they are tolerant to CBSV and resistant to CMV which is no longer a threat to farmers.
The first generated clones were tested again for purposes of increasing the level of resistance against the diseases and to improve on the level of beta carotene.
The team identified 20 clones which have been tested for yield performance which correlates to the average yield rate of 30 tonnes per hectare but the target is for farmers to attain more by embracing best agronomy practices.

Targeted farmers
The team is at the stage of engaging farmers in participatory trials and the target is farmers from Busia District who have been growing land race cassava varieties with relatively yellow tubers but lacking beta carotene.
This too applies to farmers in Arua who obtained land race yellow fleshed varieties from Democratic Republic of Congo (DRC) but are susceptible to CMV.
The target is areas which are prone to malnutrition and people who consume cassava which is boiled and smashed into bread and thereafter consumed with sauce. This is common in Lango sub region, Kasese and West Nile.
The target is not for farmers who are processing cassava into flour because by the time the cassava is
dried and processed some percentage of the beta carotene and vitamin A, zinc and Iron food nutrient would be lost.
The next step which is due this year is to engage the farmers to boil the cassava and this will be tested to establish if the beta carotene content is not affected after boiling.
The scientists are expecting to release this variety by 2021.
Farmers will be sensitised on value addition by using its flour for baking confectionaries such as bread, cake and biscuits among others.
Scientists working at the Bio nutritional lab at NaCCRI are already testing to ensure the beta carotene nutrition level in the final product is actually 50 per cent or more.