The Midwest Chestnut Producers Council and Chestnut Growers Inc. have generously committed to donating $10,000 to chestnut research at Michigan State University over the next two years. Alongside funding from MSU Project GREEEN and the Specialty Crop Block Grant, the donation will assist Monique Sakalidis, assistant professor in the MSU Department of Plant, Soil and Microbial Sciences and Department of Forestry, and colleagues as they research pathogens affecting chestnut kernel quality.

Commercial chestnut production has become a significant agricultural commodity in Michigan, the leading chestnut producer in North America. In 2016, more than 250,000 pounds of chestnuts were harvested by members of the state’s cooperative, Chestnut Growers, Inc., which represents 34 full-time growers and approximately 30% of the state’s commercial orchards. An additional 700 acres of commercial chestnut orchards produce thousands of pounds of nuts each year. Michigan chestnuts are primarily sold for fresh consumption but are also processed for value-added products, including chips for brewing and gluten-free flour. Chestnut production is expected to increase over the coming years as many traditional horticultural farmers look to diversify.

As the industry continues to evolve and grow, nut quality has become a major focus with a special emphasis on controlling brown rot. Brown rot caused by the fungus Gnomoniopsis smithogilvyi results in necrosis of the chestnut kernel. The necrosis increases after harvest and makes the nuts undesirable. In 2017, Sakalidis found that 80% of Michigan orchards that were surveyed (total of 25 orchards) contained chestnuts with brown rot symptoms. Brown rot infection rates increase while in storage and as the nuts go to the market. As there are no visible external symptoms, the disease can only be diagnosed when the nuts are cut open and examined, making them unsaleable for the fresh nut market.

Sakalidis and her team plan to work with growers to determine the extent of the brown rot problem in Michigan and, alongside Dan Guyer, evaluate a postharvest heat treatment option that may offer a solution to this issue but will not impact the quality and salability of nuts destined for the fresh market.