Barley Barley Crop Icon Brassicas Brassicas Crop Icon Sugar Beet Sugar Beet Carrots Carrots Icon Leeks Leek Icon Maize Maize Icon Oilseed Oilseed Icon Onions Onions Icon Other Cereals Other Cereals Icon O R T Peas And Beans Peas and beans Icon Potatoes Potatoes Icon Salad Crops Salad Crops Icon Soft Fruits Crops Soft Fruits Icon Top Fruits Crops Top Fruits Icon Wheat Crops Wheat Icon Calendar Calendar icon Arrow Next Arrow Previous Close Checkmark

Common Scab

Streptomyces scabies

Pathogen

Actinomycete (closely related to a bacterium)

Hosts

Potatoes, beetroot, radishes, carrots, turnips, swedes and a range of weed species.

Symptoms

Shallow and irregular blemishes on the tuber, occasionally with a raised appearance. Deep cracking and pits develop in severe cases.

Development

The main source of the disease is infected soil. It exists as a free-living organism which infects tissue via lenticels (pores in the tuber surface) or wounds caused by machinery or pests. Infection occurs soon after tuber initiation and the plant responds by producing loose corky tissue which enlarges to form scabs as the tuber swells. It does not develop and spread in storage.

Favourable Factors

Dry, warm soil conditions and light alkaline soils.

Importance

A commonly occuring disease of potato tubers and although it may not affect their yield, it can reduce their market value because infected tubers are less attractive and it can lead to considerable peeling wastage.

Control

Identification and Management of potato diseases

Find out more information on the key disease threats to your potato crop. For each disease you will find out the importance of the disease in terms of potential yield penalty, how to identify the disease in its early stages and our advice on the best control strategies.

View now