Onion Downy Mildew: Onion downy mildew is a fungal disease that affects the leaves of onion plants.

Fusarium Basal Rot: Fusarium basal rot is a fungal disease that affects the roots and basal plate of onion plants, causing rotting and decay.

Botrytis Neck Rot: Botrytis neck rot is a fungal disease that affects the neck of onion plants, causing the tissues to turn soft and watery.

White Rot: White rot is a fungal disease that affects the roots of onion plants, causing rotting and decay.

Purple Blotch: Purple blotch is a fungal disease that affects the leaves of onion plants, causing purple-colored lesions.

Smut: Smut is a fungal disease that affects the leaves, stems, and bulbs of onion plants, causing blackened areas on the plant.

Stemphylium Blight: This is a fungal disease that affects the leaves of onion plants, causing yellowing, spotting, and blighting.

Iris Yellow Spot Virus: Iris yellow spot virus is a viral disease that affects the leaves of onion plants, causing yellowing and necrosis.