Effect of Variety and Apron Star on Incidence and Severity of Cercospora Leaf Spot Disease of Cowpea (Vigna unguiculata) in Sokoto, North-Western Nigeria

Cowpea (Vigna unguiculata L.) Walp is known to be affected by several fungal, bacterial and viral diseases. One of such fungal diseases reported to cause serious yield loss in the cowpea is the Cercospora leaf spot disease caused by two fungi namely, Cercospora canescens Ellis and Martin and Cercospora cruenta [1]. Yield loss attributed to Cercosora leaf spot in susceptible cowpea variety varies between 36% and 42% [2]. Out of 75 cowpea varieties evaluated in 1999 and 2000, about 42% of the germplasm was found to be susceptible to Cercospora diseases [3], with Ife brown having 80% Cercospora incidence on the field. According to Booker and Pathmanathan, a Cercospora leaf spot disease is a serious limitation to cowpea production, resulting in yield loss of as much as 42 percent. Due to the high cost of chemicals used in the control of Cercospora leaf spot disease of cowpea, equipment, and misuse of these chemicals, which cause a harmful effect in the environment, has been the major factors that necessitate the search for other methods of disease management. It therefore, the use of resistance varieties, thus, can help to reduce the incidence and severity of Cercospora leaf spot disease of cowpea.