Critical Review of Onion Pathologies and Modern Countermeasures in Agroecological Systems

Onion cultivation is significantly affected by a range of diseases caused by fungi, bacteria, and viruses, which lead to substantial yield and quality losses. This article provides a comprehensive overview of the most common onion plant diseases, including powdery mildew (Peronospora destructor), throat rot (Botrytis allii), stem and white rot (Fusarium and Sclerotium spp.), rust (Puccinia and Melampsora spp.), bacteriosis (Erwinia spp.), mosaic virus, and onion rust (Urocystis cepulae). For each disease, typical symptoms, sources of infection, environmental conditions favoring development, and transmission methods are outlined. Special attention is given to preventive agronomic practices such as crop rotation, soil treatment, seed disinfection, and timely harvesting. Additionally, specific chemical and biological control measures are discussed to support disease management strategies. This study aims to inform farmers, agronomists, and agricultural researchers of effective approaches for protecting onion crops and ensuring sustainable vegetable production.