A & L Biologicals - 2140 Jetstream Rd, London, ON, N5V 3P5 (519) 457-2575

Potato Powdery Scab

Powdery scab
Powdery scab is a disease cause by Spongospora subterranean f. sp. Subterranean that produces small lesions on the surface of tubers. As a consequence, it reduces the marketability of the potatoes due to undesirable cosmetic features, similar to pimples, on the tuber surface (Figure 1). These lesions can be easily removed by hand, but industrial potato peeling machines have far more difficulty removing them. This can lead to large financial losses for the seed producers because the potatoes they send to the factories often have more lesions than the machines are capable of removing. Moreover, powdery scab infected seed tubers can lead to reduced weight and yield of potatoes and render the plant more susceptible for other pathogens. Awareness of this disease has increased over the last 30 years in many countries and now known to be found worldwide where potatoes are cultivated.
At A&L Biologicals, we are developing specific techniques to reduce Spongospora subterranean f. sp. Subterranean populations on potato tubers using biological control products. We have developed a rapid diagnostic test to accurately detect and quantify the presence of Spongospora subterranean F. sp. DNA on infected tubers. This this test can be used to verify the effectiveness of the treatments and determine if they are reducing disease incidence.

Effect of powdery scab on potato tuber surface

Potato common scab project
Similar to powdery scab of potato, common scab of potato disease is arises throughout worldwide and it is most commonly caused of Streptomyces scabies. Symptoms of potato contains dark-brown, corky lesion on the surface of tuber and decreases value of marketability. There has not been successful disease management reported for common scab on potato and neither biological nor chemical agents have been shown their efficiency to reduce diseases susceptibility to tubers. However, reduced disease severity found from naturally suppressive soil indicated that presence of antagonistic microorganisms may able to prevent infection of S. scabies from potato tubers. These bacteria is able to resist against S. scabies through producing certain antibiotics.
In A&L biologicals, we have collected numerous bacterial and fungal species across the Canada and found that many of species can be used for bio-control agent. We are now testing specific strains of bacteria as potato tuber treatments as a means to protect tubers from S. scabies and spread of S. scabies to non-infested soil. In order to quantify S. scabies from potato tubers and soil after tuber treatment of bio-control agent, we employ molecular technique such as PCR to quantify S. scabies.

Effect of common scab on potato tubers

A bacterium resistant against S. scabies by releasing antibiotics