Maine Potato Board plant pathologist/lab manager Andrew Plant said during a meeting Feb. 12 that the 2019-20 results of the Maine Department of Agriculture, Conservation and Forestry’s annual Post-Harvest Test was the worst since 2012-13, Bangor Daily News reports.
Plant said that 7.3 percent of all seed potato lots were rejected because of the presence of pathogens within the crop, such as the bacteria Dickeya solani, which is known to cause potatoes to rot in storage, as well as potato virus Y, which can cause rot or affect sprouting.
It was nearly 70 percent higher than the 2018-19 season’s number of 4.4 percent, and the worst since 10.7 percent rejected in 2012-13.
Plant said that for a lot of seed potatoes to be rejected, more than 5 percent of the sample needs to test positive for pathogens. He said about 700 acres of seed potatoes met that threshold.
“Acre-wise, our rejections just about doubled since last year,” Plant said.
Plant said that the increase is part of a larger uptick in pathogens in potatoes since 2010. He said that prior to that year, it was fairly common for only 1 percent of potato lots to not pass inspection, but the recent harvest had shown much higher numbers of potatoes infected with pathogens.