Stemphylium blight: Dark brown blotches on leaves
Pathogen: Stemphylium vesicarium Symptoms An attack begins with small, light yellow to brown, watery spots. After a while these develop...
Stemphylium blight: Lesions formation on leaves
Pathogen: Stemphylium vesicarium Symptoms Lesions are often more numerous on the sides of onion leaves facing the prevailing wind.The...
Stemphylium blight: A leaf miner scar
Pathogen: Stemphylium vesicarium Symptoms Since this fungus is usually found co-infecting with Alternaria porri, symptoms are identical...
Rust: Teliospores on onion leaf
Pathogen: Puccinia allii (synonym: P. porri) Symptoms Dark brown fungal teliospores( final stage in the life cycle of a rust fungus)...
Rust: Advance stage of infection
Pathogen: Puccinia allii (synonym: P. porri) Symptoms When disease pressure is severe, leaves turn yellow and die prematurely. Dark brown...
Rust Appearance of lesions on onion leaves
Pathogen: Puccinia allii (synonym: P. porri) Symptoms Small, circular, white to tan lesions appears along leaf veins. Lesions develop...
Rust: Yellowing of leaf tissue
Pathogen: Puccinia allii (synonym: P. porri) Symptoms The leaf tissue surrounding the pustules turns a pale yellow. Later on in the...
Rust: Development of lesions
Pathogen: Puccinia allii (synonym: P. porri) Symptoms The disease first appears as small, circular, white to tan lesions along leaf...
Rust: Pustules formation on leaves
Pathogen: Puccinia allii (synonym: P. porri) Symptoms Rust brown clusters of spores (pustules) forms all over the leaf. The leaf tissue...
Pink root rot
Pathogen: Phoma terrestris (syn. Pyrenochaeta terrestris) Symptoms The disease may appear either in young seedlings or later in the...