Cornell Battles Snap Bean Crop Loss Due to White Mold

An aerial view of a snap bean field at Cornell’s New York State Agricultural Experiment Station in Geneva, N.Y. Photo provided.

The snap bean has an arch nemesis: white mold.

A project led by a College of Agriculture and Life Sciences researcher is aimed at reducing losses in this important crop by optimizing disease control for the fungus.

Snap beans, a legume more commonly known as the green bean and waxy yellow bean, generates hundreds of millions of dollars in agricultural revenue annually. It’s the fifth largest vegetable crop in the U.S., and New York state ranks second in processing and fresh market production. Every year, however, white mold, caused by the fungus Sclerotinia sclerotiorum, wipes out a substantial number of snap bean crops across the state and the nation.

“White mold is among the most devastating and recalcitrant plant diseases worldwide and results in major losses to numerous vegetable and field crops, such as sunflower, dry beans, and soybeans,” said Sarah Pethybridge, assistant professor in the Plant Pathology and Plant-Microbe Biology Section of the School of Integrative Plant Science and the project’s principal investigator.

“Our project aims to use a multidisciplinary approach to improve detection of the right time to control white mold in order to reduce crop loss,” she said.

U.S. Senator Charles Schumer said, “Cornell is a national leader when it comes to cutting-edge agricultural research. This funding will allow Cornell to continue its critical research on white mold management to benefit American farmers. As we all know, agriculture is a vital part of New York’s economy, which is why I am committed to securing resources that ensure universities like Cornell have the tools they need to continue to be on the forefront of agricultural research and innovation.”

In recent years, Pethybridge and her team discovered that snap bean growers manage white mold by proactively applying fungicides to fields considered at high risk. Yet due to poor timing of application, significant failures continue to occur, Pethybridge said.

She is collaborating with Cornell Cooperative Extension and Rochester Institute of Technology’s (RIT) Chester F. Carlson Center for Imaging Science to get a fix on precisely when to act and how best to do it. The findings could have important implications for farm economics and environmental protection, as the research could provide guidance for more effective applications of costly fungicides.

“For this disease, the main critical issue is trying to protect the flowers because the spores of the pathogen can only affect them. It then uses the flowers as a nutrient source and damages the green tissue,” said Pethybridge.

Senator Kristen Gillibrand, a member of the U.S. Senate Agriculture Committee, said, “Cornell University is one of the most innovative institutions in the country and an ideal place for this significant federal investment, which will give Cornell the tools to continue its groundbreaking advanced research to strengthen the nation’s food and agricultural industries.” 

With the help of RIT’s sensors and drones, the researchers plan to collect spectral imagery and light detection and ranging (lidar) data, to detect spectral and structural indicators that are related to the development of the plant’s flowers. Many of these remote sensing tools provide inputs the naked eye cannot see, for example, collecting near-infrared light to assess plant stress.

“This way we can pinpoint the optimal times to use fungicide for the greatest outcome and economic impact – and we can better use the tools we already have to be able to manage the disease,” Pethybridge said.

But all snap bean fields are not equal. The density of the snap bean canopy also impacts its susceptibility to white mold. Pethybridge’s team will model the conditions under which plants are at highest risk and monitor them with different sensors that measure green leaf area or provide assessments of canopy structure, which in turn impacts the microclimate within a crop.

Thanks to their partnership with Cooperative Extension, outcomes will be available for immediate adoption by industry and growers who are already deploying sophisticated sensors and aerial systems to monitor their crops.

“This project offers a unique opportunity to realize the benefits of precision agriculture by providing robust and reliable support to decision-making that influences both profitability and productivity,” Pethybridge said.

The project received $299,692 from the U.S. Department of Agriculture’s Agriculture and Food Research Initiative. Co-principal investigators include Jan van Aardt and Carl Salvaggio of RIT’s Chester F. Carlson Center for Imaging Science, and Julie Kikkert of Cornell Cooperative Extension’s Regional Vegetable Team.

Jennifer Savran Kelly is a writer for the College of Agriculture and Life Sciences.