Tanier (Xanthosoma sagittifolium), the second most important root crop in Puerto Rico, has undergone yield decline in recent years due to a root rot syndrome locally known as "Mai Seco". Water management patterns may play a major role in the development of this syndrome since pathogenic microorganisms and physiological activities of plants are affected by the availability of water. Three experiments at different water levels were established in a Coto clay soil (Tropeptic Eutrustox) using tanier cultivar Alela. Experiment A consisted of soil saturation, B temporary interruption of irrigation, and C the combined effects of drought and flooding. An inverse linear tendency was found between water levels and severity of "Mai Seco" but not on yield. No significant tendencies were observed for interrupted irrigation or combined effects of drought and flooding on "Mai Seco" and yield. A good water management preventing moisture stress may reduce dry root rot while periodic drought may enhance this condition.