Effects of Temperature and Relative Humidity on the Germination and in vivo Infection Dynamics of Sphaerotheca fuliginea fungus on Watermelon (Citrullus lanatus) in Sokoto, Nigeria

Abstract

Study’s Excerpt: • The research aimed to determine the effects of temperature and humidity on Powdery mildew Pathogens of Watermelon. • Sphaerotheca fulginea subjected to different temperature and humidity levels. • Temperature of 30°C was found optimum for fuliginea conidial germination and Invivo infection. • High Humidity of >70% triggered the fuliginea infection on Watermelon. Full Abstract: Powdery mildew (PM) caused by (Sphaerothe cafuliginea fungus) is a major foliar disease affecting greenhouse and field-grown watermelon throughout the world. Infection at early stage of watermelon plant by S. fuliginea reduces seedling and vigor, causes premature desiccation of leaves. This research aims to investigate the effects of temperature and relative humidity on the conidial germination, and in vivo infection of Sphaerotheca fuliginea on healthy watermelon plant. The experiment was laid out on Completely Randomized Design (CRD) in the laboratory with (5) replications in each case. Conidia of Sphaerotheca fuliginea was subjected to different temperature and relative humidity of (30, 35, 40, 45 °C and 52%,63%,86% , 94% respectively) for conidial germination, mycelium length, width and in vivo infection. Results showed that lower temperature ranges (30°C-35°C) and higher relative humidity (>70%) often to enhances the conidial germination of Sphaerotheca fuliginea and in vivo infection, research revealed how Powdery Mildew be triggered by lower temperature of 30°C and high relative humidity of ~94% in watermelon (Citrullus lanatus) in Shagari Local Government Area of Sokoto State. Based on the result obtained it can be recommended that the best time for Watermelon cultivation around Shagari Local Government Area should be from February to May in which temperature and relative humidity level are not favourable for the development of Powdery Mildew.

Keywords

• Completely Randomized Design
• Sphaerotheca fuliginea
• Temperature
• Relative Humidity