There is another potential threat on the horizon to the health of the Island's number one cash crop.
Dickeya has been present for several years in Europe and has now been found in Ontario and several American states. The general manager of the PEI Potato Board said there is no sign of the disease in PEI and industry representatives are working hard to keep it that way.
"It came on the scene in North America about two years ago," Greg Donald told industry representatives who gathered in Summerside recently for a potato seminar sponsored by the Department of Agriculture and Fisheries.
Dickeya is similar to blackleg but both Donald and Dr. Solke deBoer warned its impact is much more serious. Dr. deBoer is a retired scientist with the Canadian Food Inspection Agency. Donald said the disease was first detected in Florida and Ontario in 2014 and by the next year, it had spread across many of the major potato growing areas south of the border including Maine.
The board general manager said there are currently six laboratories testing for the pathogen, including one in New Brunswick. He noted Dickeya can be present in a wide range of hosts plants and can be spread in stagnant surface water.
Dickeya is not yet listed as a quarantined pest in Canada but any symptoms must be recorded in a seed certification inspection. Donald said the Island industry has been working with the Canadian Food Inspection Agency on the issue and is running a project that sees samples tested for Dickeya at the Potato Quality Institute laboratory in Charlottetown using the same testing methods as the New Brunswick laboratory that is testing nationally.
"We are still accepting applications to participate in the testing program in 2017," he said.
Good sanitation practices are a key way to help prevent the disease, and he suggested producers use protocols recommended for other bacterial disease. Donald added "we want to give the industry as much information as we can to hopefully prevent the disease from gaining a foothold here and, if it does come, provide information on the best way to eradicate it."
Dr. deBoer explained there are two types of Dickeya that can cause blackleg, and they are both more severe than the blackleg most growers are familiar with, that is officially known as atrosepticum. Blackleg is a disease characterized by the seed piece decay, black pigmentation of the stem and the soft rot of tubers.
While atrosepticum blackleg tends to form at lower temperatures, Dr. deBoer said Dickeya blackleg tends to favour higher temperatures for growth. As well, the symptoms of atrosepticum blackleg are usually readily identifiable, while Dickeya blackleg may be restricted to the internal pith tissue of the stem making it harder to detect.
While atrosepticum blackleg can cause limited yield loss, dr. deBoer warned the impact of Dickeya blackleg can be much more severe. He warned Dickeya blackleg can develop during planting from bacteria found in seed tubers. It can also grow in storage post harvest.
He stressed it is important to the plant only high quality seed and he agreed with Donald proper sanitation is vital to halting the spread of the disease. Since the bacteria that cause the disease can spread quickly on equipment, he added it is vital to ensure all equipment is disinfected, especially if it is moving from field to field.
"Dickeya can survive in soil and water but only for a limited time," he said. "It can be spread by inspects, but there is no evidence that is a major cause."