Study the Application of Insecticide Program and its Impact on the Relationship between Leaf Miner Liriomyza huidobrensis Populations and the Early Blight Disease in Potato Fields

The early blight caused by Alternaria solani is a serious disease that threats potato plants during the growing seasons. This study investigated the relationship between leaf miner infestation and the incidence and severity of early blight in potato fields in El-Minya governorate, Egypt. An insecticide program included three different insecticides i.e., Abamectin 1.8 % EC, Fipronil 20% SC, and Imidacloprid 35%SC was applied to study its impact on leaf miner population as well as early blight incidence and severity. The leaf miner population was monitored during 2020 and 2021 growing seasons. Early blight incidence (DI), disease severity (DS), and area under the early blight progress curve (AUDPC) were estimated along with leaf miner infestation. The results showed high significant correlation between leaf miner infestation which represented by (the number of leaf miner adults, larvae, mines/leaflet and the minded leaf area) and the infection by A. solani which represented by (DI and DS of early blight) during the two growing seasons. The application of the insecticide program significantly decreased the number of leaf miner adults, mines, larvae, and minded area% as well as DI and DS of early blight. Also, it affected the correlation between the number of leaf miner adults as well as DI and DS. This study expands our knowledge about the relationship between leaf miner infestation and A. solani infection in the open potato fields and how that could be useful in setting up an effective integrated pest management program to control both leaf miner and early blight.