May 31, 2022Penn State scientists to explore postharvest fruit rot
Scientists in Penn State’s College of Agricultural Sciences have received a U.S. Department of Agriculture grant of nearly $313,000 to study the effects of postharvest fruit decay.
The research is designed to support the mid-Atlantic apple industry and consumers by reducing apple decay during storage, according to Kari Peter, associate research professor of tree-fruit pathology. She added that apples are among the most consumed fruits in the U.S., second in popularity only to bananas.
“The apple industry contributes nearly $4 billion annually to the economy, with the mid-Atlantic apple growers and packers producing nearly 760 million pounds of apples each year,” said Peter, who is based at Penn State’s Fruit Research and Extension Center in Biglerville.
However, postharvest fungal fruit rots result in crop losses from 1% to 15% annually, constituting a significant threat to the U.S. apple industry. “Postharvest rots reduce fresh fruit for consumption and significantly contribute to food waste,” Peter said. “In addition to product losses, costs associated with sorting, repacking and additional fungicide treatments can worsen the economic impact of losses due to rot.”
She explained that the most frequent postharvest rots of apples are blue mold, caused by Penicillium expansum and other Penicillium species, and gray mold, caused by Botrytis cinerea. The fungi causing blue mold are of most concern since several species produce the mycotoxin patulin, which is a food safety issue.
“Unfortunately, no apple varieties are resistant to these diseases, and management options of postharvest apple rot are limited,” Peter said. “Growers rely on continued use of synthetic fungicides, of which there are few and which have caused the emergence of fungicide-resistant strains in apple packinghouses. This reduces their utility as control options in storage since fungicide failure is more likely to occur.”
Peter said the three-year study, funded by USDA’s Crop Protection and Pest Management program, will fill a major gap in knowledge for postharvest apple diseases and appropriate management strategies for the mid-Atlantic. The researchers will accomplish this by identifying the fungi causing postharvest apple rots in Pennsylvania and Maryland packinghouses to determine where the fungal spores originate. They also will test fungicide resistance among the fungal pathogens collected against the four postharvest fungicides used.
Additionally, the scientists will investigate whether wooden and plastic bins serve as viable pathogen sources for rots. They also will evaluate the effectiveness of new methods, such as fogging and organic controls, for sanitizing bins and other surfaces to limit postharvest apple decay.
This work, which will be shared through Penn State Extension in English and Spanish, is expected to benefit many apple producing areas, including New England, New York, Michigan, the Midwest and the Southeast, noted Peter.
“Postharvest research in pome fruit in the eastern U.S. has been understudied,” she said. “This grant affords us the ability to make significant in-roads to help the apple industry limit food loss related to postharvest diseases.”
Collaborators include Penn State doctoral student Johanny Castro; Penn State Extension educators Daniel Weber, Don Seifrit and Maria Gorgo-Gourovitch; Bryan Butler, an educator with the University of Maryland Extension; and Wayne Jurick, research plant pathologist in USDA’s Applied Research and Development Program, Beltsville, Maryland.
The project will be among those featured at a future USDA Food Loss and Waste Innovation Fair. This free, virtual fair highlights businesses creating or implementing state-of-the-art technical solutions to reduce food loss and waste throughout the food system — from farm to table — and highlights USDA activities in this space.
– Amy Duke, Penn State; Photo courtesy of Johanny Castro, Penn State