Vegetatively-propagated crops such as potato, sweetpotato, cassava, yam, and banana serve as food security staples for many smallholder farmers in developing countries. Due to the scarcity and/or expense of disease-free seeds, these farmers tend to reuse planting material over multiple generations, resulting in pathogen build-up and consequent yield reductions. This problem of 'seed degeneration'is complex and the choice and success of management decisions are influenced by numerous factors. We address this challenge by