Damages caused by strains of cowpea severe mosaic virus in Vigna unguiculata cv. Pitiuba

Abstract

The strains of cowpea severe mosaic virus (CpSMV) isolated in Ceará (CpSMV-CE) and Piauí (CpSMV-PI), Brazil, caused the following reduction rates, 40 days after sowing, in plants of Vigna unguiculata inoculated at 10, 20 and 30 days after sowing, respectively: plant height (CpSMV-CE), 56, 27, 16; CPSMV-PI, 67, 27, 21); leaves/plant (CpSMV-CE, 46, 24, 9; CpSMV-PI, 52, 35, 29); stem dry weight (CpSMV-CE, 83, 40, 11; CpSMV-PI, 85, 53, 21; root dry weight (CpSMV-CE, 76, 40, 24; CpSMV-PI, 72, 38, 17); and leaf dry weight (CpSMV-CE, 79, 44, 18; CpSMV-PI, 81, 54, 34). The reduction rates evaluated 100 days after sowing were as following: pod length (CpSMV-CE, 41, 46, 18; CpSMV-PI, 38, 33, 19); pods/plant (CpSMV-CE, 77, 70, 33; CpSPMV-PI, 48, 47, 17); seeds/pod (CpSMV-CE, 22, 38, 2; CpSMV-PI, 22, 11, 1); seeds/plant (CpSMV-CE, 76, 71, 32; CpSMV-PI, 53, 46, 16); production of seeds/plant (CpSMV-CE, 81, 74, 42; CpSMV-PI, 65, 54, 21) and 100-seed weight (CpSMV-CE, 52, 42, 18; CpSMV-PI, 38, 32, 15).