International Institute of Tnpical Agriculture, Oyo Road, PMB. 5320, Ibadan, Nigeria and IITA/USAID/Tanzania Research Project Ministry of Agriculture, Dares Sulam, Tanzania
*Present address: Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA.
In screening of 190 cowpea [Vigna unguiculata (L.) Walp.] accessions in Tanzania, by stem-stab inoculation with the blight organism, Xanthomonas campestris pv. vigmcola, 21 accessions reacted as resistant and 20 as moderately resistant. Comparisons of the reactions in five screening tests carried out in Tanzania India, Nigeria and Puerto Rico showed differences in the pathogenic behaviour among the cultures of the blight organism prevalent in these countries. Cowpea accessions which could be used as differentials for identification of pathogenic races and monitoring the stability of the varietal resistance are suggested.
