Identification of suitable seed regeneration sites for photoperiod-sensitive cowpea germplasm

To determine an appropriate location to regenerate photoperiod-sensitive cowpea [Vigna unguiculata (L.) Walp.], seed production and virus contamination data were measured at Isabela, PR, St. Croix, VI, and Griffin, GA for six photoperiod-sensitive cowpea accessions. The results indicate that Isabela was best suited for seed regeneration of photoperiod-sensitive cowpea. Seed production at Isabela was equal to or greater than that at either of the other two locations for these accessions. Virus infection of plants and of seeds was high at Griffin. However, little virus infection occurred at Isabela and at St. Croix. The systematic approach used in these tests can be used as a model for curators in the National Plant Germplasm System and others to determine the best environment in which to regenerate germplasm.