New PMN webcast: Black Dot Root Rot of Potato

"Focus on Potato"of the Plant Management Network has published its latest webcast, titled:

“Black Dot Root Rot of Potato"

by Barry Jacobsen,
Professor and Extension Plant Pathologist
at Montana State University.

Black Dot Root Rot, both a widespread and important disease of potatoes, is the latest webcast title to be published in Focus on Potato, an industry crop management training resource for potato growers and consultants.

This 15-minute presentation, authored by Barry Jacobsen, Professor and Extension Plant Pathologist at Montana State University, will give viewers an overview of the Black Dot Root Rot disease, as well as the options for controlling it.

Specifically, Dr. Jacobsen covers Black Dot's causal fungus, host range, and survivability. He also discusses potential yield losses from Black Dot.

Finally, Jacobsen helps users with diagnosis and treatment of this economically important disease.

Black dot has been proven to be both a widespread and important disease of potatoes. The causal fungus, Colletotrichum coccodes, is found worldwide, has a broad host range and can survive as sclerotia in soils for long periods.

Yield losses of up to 40% have been shown for some cultivars in inoculated experiments with many commonly grown cultivars showing yield losses of 10-20%. Yield losses occur both through root rot and premature dying and from tuber blemishes that resemble Silver Scurf. Black dot is commonly involved in the early dying complex with Verticillium wilt and nematodes.

Control of this disease can involve soil fumigation with Vapam or KPam, use of seed treatments such as Dynasty to prevent spread by seed, in furrow fungicide applications followed by post emergence fungicide applications, long rotations and production practices that reduce stress. While no cultivars are immune, cultivars with <5% yield losses have been identified.

This webcast can be accessed without subscription until February 28, 2011.

View the webcast