White Blister Rust or Staghead of Brassicas

Albugo candida

Names:

White Blister.

Description:

A fungal disease causing soft looking, white patches mainly on the underside of leaves that become raised, powdery and blister like. It starts on the topside of leaves as small raised, yellow green spots. Leaves may become distorted.

Species Affected:

Mainly Brassicas.

Bittercress, Chinese Cabbage, Hedge Mustard, Horseradish, Radish, Shepherds Purse, Swede, Turnip and Wild Radish are very susceptible.

Brassica campestris varieties of Rapeseed are susceptible.

Occurs on Broccoli, Cabbage, Cauliflower, Brassica napus varieties of Canola.

Uncommon on other species.

Biology:

Favoured by cool, wet conditions.

Infection requires wet leaves.

Survives on crop residues, the soil and on Brassica weeds.

Spread by insects, wind and rain or irrigation.

It is not related to the normal "Rust" diseases.

Life Cycle:

Origin and History:

Distribution:

Significance:

Very damaging to Chinese Cabbage.

Damaging on Brassica campestris varieties of Rapeseed.

Rarely an economic problem on Broccoli, Cabbage, Cauliflower or Brassica napus varieties of Canola.

Management and Control:

Remove crop residues by deep burial or burning soon after harvest.

Control Brassica weeds.

Plant seed harvested from disease free areas.

Increase the time between successive B. campestris crops or grow Brassica napus varieties if the disease is proving difficult to contain in Oilseed Rape areas.

Rotate to tolerant crops for 3-4 years.

Fungicides are generally not effective.

Related and Similar Species:

References:

1206



1205

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 for more information.