Studies on varietal resistance to stem rot (Phytophthora vignae Purss) in the cowpea

Abstract

The reaction of local and introduced cowpea varieties and some other legume species to stem rot (Phytophthora vignae) in pot tests, nursery plots and field trials is described. On the basis of their reaction the varieties may be placed in three groups. The first includes those such as Poona and Reeves which are susceptible under all conditions of testing. The second includes Malabar, Giant and some others which are susceptible in pots but show variable reaction under other conditions. The varieties in the third class, which exhibit complete resistance, include Blackeye 5 and Havana. It is shown that the resistance to stem rot possessed by Blackeye 5 is dominant over the susceptibility possessed by Poona. Evidence is produced to show that control of the disease can be achieved by the use of resistant varieties either introduced from overseas or synthesised by plant breeding.