Northern stem canker found by NNYADP survey

A new challenge for soybean growers in 7 state counties

A serious crop disease called northern stem canker has been confirmed for the first time in Northern New York soybean fields as part of the Northern New York Agricultural Development Program-funded NNY corn and soybean disease diagnosis and assessment database building project.

NSC occurs in most Midwestern states and in Ontario, but Cornell Plant Pathologist Gary C. Bergstrom said the finding in Jefferson County and in six other counties elsewhere in the state is the first confirmation of NSC in New York or the northeastern U.S.

Reported yield losses to NSC in the Midwest have ranged from minor to in excess of 50 percent.

With additional funding from the New York Soybean Check-off Program, Cornell Cooperative Extension/CCE field crop educators Michael E. Hunter and Kitty O'Neil scouted soybean production fields in all six Northern New York counties: Clinton, Essex, Franklin, Jefferson, Lewis and St. Lawrence.

Hunter and O'Neil recorded observations on field conditions and diseases, and collected and sent plant samples to the field crop pathology laboratory at Cornell University for positive diagnosis of suspected disease problems.

"One option soybean producers can immediately consider to manage NSC is to plant canker-resistant varieties,' said Hunter, who works with farmers in Jefferson and Lewis counties.

"We are encouraging growers and crop advisers to learn how to recognize the symptoms and differences of northern stem canker and other late-season crop diseases," O'Neil said.

NSC was diagnosed in plant samples from soybean fields in Jefferson, Livingston, Niagara, Ontario, Orleans, Seneca and Wayne counties. Diagnosis was based on characteristic symptoms, laboratory isolation of the causal fungus, and confirmation of a portion of its DNA sequence.
Northern stem canker is caused by the fungus Diaporthe phaseolorum var. caulivora and differs from a related fungus, Diaporthe phaseolorum var. meridionalis, which causes southern stem canker throughout the southern U.S.

"This research partnership with the Northern New York Agricultural Development Program is providing growers with early notice of common pest and crop diseases and, in the case of northern stem canker, a new challenge so they can quickly respond to maintain crop health and productivity and farm profitability," said New York Corn and Soybean Growers Association Executive Director Julia C. Robbins.

A complete report is posted in the field crops section of the Northern New York Agricultural Development Program website at www.nnyagdev.org. Growers also can contact their local Cornell Cooperative Extension office for more information.