Some Chemical and Biological Methods to Control Pepper Root Rot Disease in Iraq

Abstract

Background: Pepper growing fields in the Babil and Wasit governorates in Iraq, are suffering from a decline in production due to the spread of root rot diseases. The use of biological control techniques, such as the use of beneficial bacteria in the rhizosphere and natural plant extracts, along with chemical fungicides, has recently contributed to reducing the damage of plant pathogens globally. Methods: In this research, the main cause of root rot disease in pepper plants was isolated and diagnosed using polymerase chain reaction technology using (TEF-1α) gene, antagonistic activities of 75 rhizobacterial isolates, natural extracts of garlic and nerium and the fungicides of Promess and Tecto 500 SC were tested in vitro against the pathogen, then the superior bacterial isolates were identified. The ability of biological and chemical agents to control the disease was tested under greenhouse conditions according to the completely randomized design (CRD). Result: The results of isolation showed that the fungus Fusarium solani was dominance and the isolate Fsw45 was the most virulent. 3 of 75 rhizobacterial isolates outperformed the pathogen in an antagonistic tests and identified as Pseudomonas mendocina, P. fluorescens and Staphylococcus kloosii also the fungicides and botanical extracts showed significant antagonistic activities as well in vitro. Under greenhouse conditions, the fungicide treatments excelled in disease control by 100%. As for the 3 bacterial isolates, they achieved a significant reduction in the percentage of disease incidence and disease severity index, their abilities were higher than the nerium and garlic extracts.