Protocol to Screen Cocoyam Accessions for Resistance or Tolerance to Cocoyam Root Rot Disease in Cameroon. R. P. Pacumbaba, Plant Pathology Consultant, Roots and Tuber Research Project (ROTREP), and Associate Professor of Plant Pathology, Department of Plant and Soil Science, Alabama A&M University, Normal, 35762. J. G. Wutoh, and Muyali Mary B. Meboka. Chief Scientist, and Ingenieur des Travaux Agricoles, ROTREP, United States Agency for International Development/Government of Cameroon, Ekona Research Centre, Buea, Cameroon. Plant Dis. 76:768-770. Accepted for publication 8 March 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0768.

For the first time in Cameroon, cocoyam (Xanthosoma sagittifolium) accessions of cv. Macabo (white) have been screened for resistance or tolerance to cocoyam root rot disease caused by Pythium myriotylum. Of 626 cocoyams planted in the greenhouse and screened for 21 days, 72 resistant and 210 tolerant suckers were transplanted in a field in Mamu, Cameroon, known to be infested with P. myriotylum. After 3 mo of intensive screening in the field, 42 resistant and 35 tolerant accessions of the Roots and Tuber Research Project (ROTREP) were identified.