Incidence and Severity of Virus Diseases of Cowpea (Vigna unguiculata L. Walp) Under Varying Planting Density and Insecticidal Spray Regimes

Abstract

Viral diseases are a major problem for cowpea production in Nigeria, causing yield reductions of up to 100%. To combat this, farmers use insecticide sprays and manipulate plant population densities. A field experiment was conducted in the Southern Guinea Savannah agro-ecological zone of Nigeria in 2016 cropping season to assess the impact of planting density and insecticidal spray regimes on virus diseases in cowpea. The study found that the lowest disease incidence (32.2%) was observed at a density of 25×75 cm, and the highest (41.9%) at a density of 75×75 cm. The combination of a density of 25×7 5cm with three insecticidal spray regimes had the lowest incidence (18.6%), while 75×75 cm with no insecticidal spray had the highest (66.5%) disease incidence. Thus, it is recommended to use a planting density of 25×75 cm with three insecticidal spray regimes. This study emphasizes the importance of planting density and insecticidal spray regimes in managing viral diseases in cowpea production. Farmers can utilize this information to reduce disease incidence and severity and increase yield.