Testing Tephrosia Vogelii for Resistance to Foliar Blight in Puerto Rico

Abstract

The severity of foliar blight in T. vogelii incited by T. cucumeris and M. phaseoli was significantly greater for 48- and 72-hour periods of postinoculation humidity of 100 percent than for periods of 0, 12, and 24 hours. Inoculations of 1-, 2-, 4-, and 8-week-old seedlings demonstrated that disease severity was significantly greater in the 2-week-old seedlings inoculated with either pathogen and in the 8-week-old seedlings inoculated with M. phaseoli, than in other age groups. No consistent differences in resistance to the pathogens were detected among six entries of T. vogelii in damping-off trials and foliar inoculation tests in the greenhouse. However, differences were observed for leaf yield and leaf:stem ratios among 13 lines of T. vogelii which were tested in the field under a severe epiphytotic of foliar disease. Some of these differences were associated with disease resistance and the remainder with the inherent agronomic differences between lines.