LABORATORY AND FIELD EVALUATION OF TOMATO EARLY BLIGHT (ALTERNARIA SOLANI)

Abstract

Alternaria solani is a highly destructive fungal pathogen responsible for early blight in tomato (Solanum lycopersicum L.), posing a significant threat to tomato production in Pakistan. Various management approaches—including chemical fungicides, biological control agents, and plant-based extracts—have been explored to mitigate this disease. The present study evaluated the effectiveness of five plant extracts—Citrullus colocynthis, Azadirachta indica, Moringa oleifera, Calotropis procera, and Prosopis cineraria—for controlling early blight, as well as the host response of different tomato germplasm against A. solani. Aqueous extracts were prepared at 2.5%, 5%, and 7.5% concentrations. The in vivo experiment was conducted under a Completely Randomized Design (CRD) at the Faculty of Agriculture and Environment, The Islamia University of Bahawalpur.

Results revealed that foliar application of Citrullus colocynthis extract significantly reduced disease severity and incidence, achieving the lowest disease incidence at 11.57%. These findings indicate that Citrullus colocynthis possesses strong antifungal activity against A. solani while also promoting plant growth. This dual effect underscores its potential as an eco-friendly alternative to conventional chemical fungicides. However, further research is required to clarify its mode of action, environmental safety, and wider applicability in sustainable disease management strategies.