The brown root rot, a fungus that attacks alfalfa has been detected in farm fields in New York, Vermont, New Hampshire, Pennsylvania and Maine. The research was conducted by Cornell University scientists, with the first samplings conducted in 2005.
There are no effective treatments or controls for brown root rot, said Gary Bergstrom, a professor of plant pathology at Cornell. Last year, the Farm Bureau persuaded state lawmakers to spend $300,000 for research on the fungus, which can also infect vegetables and Christmas trees, he said.
Neither the Farm Bureau nor the state Agriculture and Markets Department have kept track of the number of infected acres in New York.
Brown root rot started out as a problem in Alaska and in the prairie provinces of western Canada — Alberta, Saskatchewan, Manitoba and the Yukon Territory. In eastern Canada, it has been reported only in Nova Scotia. The disease was first observed in the contiguous United States in 1996 in Wyoming and then in Idaho, Montana, Minnesota and Wisconsin. The fungus first appeared in New York in 2004 in Clinton County, Bergstrom said.
The disease’s lesions first appear as reddish-brown to dark brown areas of external discoloration, eventually progressing into the roots, said Michael Wunsch, a Cornell graduate student in plant pathology and the report’s lead author. The fungus prefers cooler soils, between 30 and 60 degrees. Infection and decay occur primarily in the late fall through early spring. Infected plants grow normally in the spring but die in mid-May to mid-June.
Bergstrom said the widespread detection of brown root rot in the testing indicates most fields already have the pathogen. He said the best thing farmers can do at this point is to buy stronger, disease-resistant alfalfa in the future.