Promotion is also needed because most communities are used to and enjoy the firm, starchy white or yellow sweet potatoes - which means the benefits of the mushy orange ones must be communicated if they are to be widely adopted.
Still, Dr Mwanga remains hopeful.
So far, the orange-fleshed sweet potato has been adopted by thousands of Ugandan farming households, with up to 237,000 households expected to be planting and eating it by 2018