Incidence of Powdery Mildew on Some Vegetables Crops in Katsina City, Nigeria

The present study deals with the survey of powdery mildews caused by S. fuliginea and E. polygoni in some important vegetables like okra, spinach, red sorrel and beans in different places of Katsina city (Barhim Estate, Kofar Durbi, Kofar Sauri, Kofar Marusa and Low Cost), Nigeria. The finding shows that the areas infested with powdery mildews are one of the important disease of vegetable crops. On the basis of shape and size of spores, the species of powdery mildew was identified as S. fuliginea on three vegetables viz; okra, spinach and red sorrel from all the localities of Katsina while E. polygoni was observed on beans only. Frequency of occurrence of the disease was highest in field of Barhim Estate (66.7%) followed by Kofar Durbi (36.1%), Kofar Marusa (35.9%) and lowest in Kofar Sauri (25%). The average frequency of occurrence of powdery mildew disease in Katsina was 41.37%. The frequency of occurrence of powdery mildew on okra was found highest in Barhim Estate (75%) while lowest was recorded in Kofar Sauri and Kofar Marusa (20%). The frequency of disease on red sorrel was found highest in Kofar Marusa (56%) and lowest in Kofar Durbi (30%). While red sorrel was free from infection in Kofar Sauri (0%). On spinach frequency was highest in Barhim Estate (66.7%) and  lowest was in Kofar Sauri (44.4%). While no infection was recorded in Kofar Durbi (0%). The frequency of disease on beans was highest in Barhim Estate (68.8%) and lowest in Kofar Sauri (44.4%), while the no infection was recorded in Kofar Marusa (0%). The severity of disease caused by S. fuliginea was highest on okra in Kofar Sauri, on red sorrel in Kofar Marusa and on spinach in Kofar Marusa. While disease severity caused by E. polygoni on beans was highest in Barhim Estate and Kofar Durbi. The highest severity of disease was found on okra (2.25- severe) followed by beans (2.00- moderate), red sorrel (1.75- moderate) and spinach (1.25- mild). The overall severity of disease was found moderate in Katsina.