Potato pathologist warns of future disease threats

North Dakota State University potato pathologist Neil Gudmestad discusses potato diseases following a presentation at the University of Idaho’s 49th Annual Potato Conference in Pocatello on Jan. 18.A leading potato pathologist warns restrictions on soil fumigants may lead to greater problems with certain diseases and a reemergence of some pathogens that are now under control. North Dakota State University Professor Neil Gudmestad also predicted during University of Idaho’s recent 49th Annual Potato Conference soil-borne genotypes of diseases that now need living tissue to survive will eventually move into the U.S. Gudmestad said there are about 150 diseases affecting potatoes, 40 of which are economically important. He said the industry faces a new pathogen about every 5.7 years. One of the most recent threats is Dickeya dianthicola, a bacterial disease that causes poor plant emergence, discolored internal stem tissue and black stems extending from rotting seed pieces. Though dianthicola now has the industry’s attention, Gudmestad warned a more aggressive type of the disease that can survive in soil, Dickeya solani, is found in Europe, and he anticipates it will eventually take hold in the U.S. “When solani gets here, trust me, we won’t even care about dianthicola,” Gudmestad said. More