An experiment was conducted on an Oxisol at the Isabela Agricultural Experiment Substation of the University of Puerto Rico (UPR) to determine the effect of consecutive plantings on the yield of taniers (Xanthosoma spp.). Eleven tanier cultivars were planted for two consecutive years in the same plot. A drastic decrease in yield occurred in the second year. An increase in the number of plants showing root-rot symptoms during the second growing season could have had an effect on plant growth and yield. Cultivars Tannia-Xanthosoma #1 and Palma had a higher percentage of healthy roots over the two-year period and were associated with resistance to the dry root-rot disease. Although these cultivars demonstrated resistance to the disease, the corms produced were rudimentary.