Fungal diseases in onions

Downy mildew :

Downy mildew disease is one of the most dangerous diseases in onions and is caused by the fungus (Peronospora destructor), which is specialized in the lily family, which includes onions and garlic.

Life cycle:

The dormant spores begin to grow in the appropriate conditions of low temperature and high humidity, forming spores that are transmitted to plants by wind and water and infect the leaves and begin to infect, forming a germinating tube consisting of mycelium that comes out from the stomata openings carrying bacterial bags that divide in the appropriate conditions and spores emerge from them to re-infect and in other conditions Suitable for sexual reproduction. Spore components can survive 4-5 years until they find a host.


The fungus infects the leaves of the coccyx in the form of small, light-colored spots, then they grow and turn brown, and appear in the onions from the same place of infection, the white fluffy growths of the fungus in conditions of high humidity and infects the flowers, it moves to the bulbs. Leaves wither and dry up, causing severe crop losses.

To control downy mildew:

Hector insecticide 80%
Matco Gold Insecticide 72%

Purple Blotch :

A fungal disease caused by a fungus (Alternaria
.porri) that affects onion and garlic crops

Life cycle:

The pathogen spends the winter in crop residues or
on the surface of the soil. The spores are produced
at night and released in the early morning and
spread by wind or rain to healthy plants to initiate

Symptoms of the disease appear 1-4 days after
infection and spores are produced by new infections
within 5 days.


It begins in the old leaves with the appearance of
small oval spots and then develops into circular or
oval overlapping ulcers that have a purple or brown
color and a yellow edge. The injury caused the
leaves to wither, twist and break the screws

To control purple blotch:

Hector insecticide 80%
Matco Gold Insecticide