Brown root rot -- a potentially serious forage crop disease -- is found throughout the Northeast

Nov 12, 2007
Brown root rot -- a potentially serious forage crop disease -- is found throughout the Northeast
Alfalfa roots with various degrees of brown root rot.

Cornell plant pathologists have detected brown root rot -- a potentially serious forage crop disease -- in the northeastern United States. It is widespread in New York, Vermont and New Hampshire and has been detected in Pennsylvania and Maine.

The findings are published in the October issue of the journal Plant Disease.

Brown root rot (Phoma sclerotioides) affects dairy farmers, as it attacks forage crops alfalfa and clover.

"It's pervasive. These were arbitrarily chosen fields, and it is present in a majority of alfalfa fields tested in the Northeast," said Gary Bergstrom, Cornell professor of plant pathology. "At this point, we have not identified effective controls for it," he added, explaining that scientists are exploring disease-resistant varieties that are adapted to the Northeast.

Brown root rot was detected in eight of 10 fields sampled in New York state, six of seven fields sampled in Vermont and five of six fields sampled in New Hampshire.

The disease's lesions begin as reddish-brown to dark brown areas of external discoloration. As the lesions progress into the internal plant tissues, they can take on corky texture, with a dark border separating the healthy and diseased tissue. Lesions that do not immediately kill the plant can vary in appearance, making it difficult to identify the disease without laboratory analysis.

"It was found in a high percentage of plants in many fields, and most lesions had advanced to the internal tissues of roots and crowns," says Bergstrom. "This suggests that it may be a serious factor in the health and persistence of alfalfa in the region."

Spatial patterns within fields suggest the pathogen was not recently introduced in the Northeast, says Michael Wunsch, Cornell graduate student in plant pathology and the lead author of this research. In North America, brown root rot has been a problem in Alaska and in Alberta, Saskatchewan, Manitoba and the Yukon Territory of Canada. In eastern North America, it had been reported only in Nova Scotia. The disease was first observed in the contiguous United States in 1996 in Wyoming and then subsequently in Idaho, Montana, Minnesota and Wisconsin.

Other authors of the study are Robert Schindelbeck, research support specialist, and Harold van Es, professor, both of crop and soil sciences.

New York farmers with questions about brown root rot in their fields should contact Cornell Cooperative Extension field crops educators for their county. Outside of New York, farmers should contact their local cooperative extension offices.

Source: Cornell University

Explore further: Fears for pink iguanas as Galapagos volcano erupts

Related Stories

Bodyguards for precious seeds—without chemical mace

May 19, 2015

Naturally occurring, plant-associated bacteria as a crop protection agent are now avail-able for use in crop protection to alleviate the contamination of soil with pesticides—arguably the most environmentally ...

New mushroom discovered on campus is the first since 1985

Nov 24, 2014

Two researchers who recently named the first new species of mushroom from the UC Berkeley campus in more than 30 years are emphasizing the need for continued green and open space on campus, as well as a full-fledged ...

Recommended for you

New book promotes care for Earth's treasures

7 minutes ago

A new and comprehensive book on how to care for the world's great natural and cultural treasures protected in national parks, written by experts from around the globe, will be launched at The Australian National ...

What is the best way to kill a cane toad?

1 hour ago

Like many pests, cane toads are killed in their thousands in Australia every year, especially by community-based 'toad-busting' groups. New research has now revealed the most humane way to do it.

Petrels tracked across the Oceans

1 hour ago

Staff at British Antarctic Survey (BAS) are following the journeys of White-chinned Petrel fledglings as they make their first journeys over the South Atlantic Ocean in search of food. The birds have been ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Argiod
1 / 5 (2) Nov 13, 2007
Mother Nature's way of telling us there are way too many humans?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.