Smudge of Allium species

Colletotrichum dematium f.sp. circinans

Colletotrichum circinans

Description:

A fungal disease that starts as small greenish spots on the Onion before harvest. During storage these become black and the Onion may shrink and sprout.

Species Affected:

Allium species.
Chives, Garlic, Leeks, Onions and Shallots.
White Onions are susceptible and most brown Onions are resistant.

Biology:

Favoured by moist conditions around harvest and in storage.
Spores are spread by wind.
Carried on plant debris from previous crops.

Life Cycle:

Origin and History:

Distribution:

Significance:

Management and Control:

Onions

Don't continuously crop to White Onions.
Protect Onions from rain after harvest and cure them promptly.
Grow brown skinned varieties if the disease persists.
Destroy crop debris.

Related and Similar Species:

References:

1291

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.