RICHLAND, Wash. – A new agricultural innovation from Washington State University may solve an ancient predicament: how to protect crop plants from cold damage at bud break. As spring brings warmer weather, plants wake up from dormancy and begin the processes of growth and flowering. But one cold night can kill those buds before they have a chance to flower and fruit.

What’s needed are tiny baby blankets that shield those emerging buds from frost. And it’s precisely an insulating coating that researchers at Washington State University have developed and are in the process of commercializing.

�³���’s��,�� and their colleagues Qin Zhang and Changki Mo are utilizing cellulose nanocrystals, CNCs, to protect grape, cherry and other flowering crop plants during frost events. Cellulose, the most common polymer on the planet, is a remarkable substance with myriad useful properties. Zhang and colleagues write in a  that CNCs are stronger than steel in a strength-to-weight face off, capable of being drawn into thin film-like layers and, best of all, are super insulative. In a recent field study, the researchers concluded that a single CNC application “improves cold-hardiness of sweet cherry and grape buds by about 2–4 °C compared to non-treated buds.”

That thin protective layer is just enough to keep baby buds snug until the cold snap gives way to the warmer spring weather which triggered the new growth in the first place.

Whiting, a horticultural physiologist, was visiting with Zhang, a chemical engineer, about something unrelated, when Zhang showed him the thermal-property data on CNCs. Whiting says he mentioned that the substance might be used to reduce frost damage and Zhang replied, “Oh, is that a problem?” In fact, it is a huge problem all over the world.

Citrus in Florida, almonds and other crops in California, coffee in Brazil, apples and pears in Portugal and Washington State–all are susceptible to frost damage, one of agriculture’s biggest killers. While the direct loss of a crop due to cold damage can be in the billions of dollars, the knock-on effects are even worse: loss of a crop means the loss of jobs for pickers, packers, processors, and retailers. A  from the UN’s Food and Agriculture Organization says that “in the USA, there are more economic losses to frost damage than to any other weather-related phenomenon.”

While there has been some innovation in terms of breeding plants for greater cold resistance, the physiological reality of a tender bud is hard to change. Other protective measures, like fabric covers, wind machines, circulating water, or heaters fueled with propane or diesel, have not changed in years. According to the agriculture-focused European Innovation Partnership, “ methods that are currently used by fruit producers are essentially the same that were used in the last decades of the 20th century.”

Whiting agrees, saying, “I’ve been working on cold tolerance for nearly 20 years, and there hasn’t been any innovation in decades.”

With a horticultural industry eager for new and effective forms of frost protection, Zhang and Whiting have formed Pomona Technologies. Pomona was the Roman goddess of fruitful abundance, and her name derives from the Latin for “fruit.” Today, pomology, a related word, is the science of growing fruits.

After a four-year series of small-scale tests that proved that CNCs did indeed offer good frost protection, the team is proceeding with both large-scale tests and moving toward commercialization. Whiting thinks that Pomona Technologies will see its first product fully available in 2022.

CNCs are widely used in medical, industrial and other applications, including cosmetics, and are already approved for various uses by the Environmental Protection Agency.

With global climate change bringing earlier spring weather in many parts of the world, some might think that frost damage will go the way of the dodo. But earlier springs mean earlier bud break, which actually  as cold snaps will still occur. That means farmers need protection they can apply quickly and inexpensively, which CNCs appear to promise.

As Whiting says, “Every flower you can keep alive is money in the bank.”

Support for the development of this technology includes funding from USDA , the , the , and the .

 

Media contacts:

• Matthew Whiting, professor, WSU Dept. of Horticulture, 509-786-9260,��mdwhiting@wsu.edu
• Xiao Zhang, associate professor, WSU Voiland School of Chemical Engineering and Bioengineering, 509-372-7647,��x.zhang@wsu.edu
• Amit Dhingra, chair, WSU Dept. of Horticulture, 509.335.3625,��adhingra@wsu.edu

By Maegan Murray, ���سԹ�

RICHLAND, Wash. – Groundbreaking nanotechnology designed to protect cherries, apples and other popular fruits from frost damage is showing positive results in tests by Washington State University researchers.

The research team recently received a $500,000 grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture to develop plant-based nanocrystals that coat and protect fruit buds during cold spells in the spring, when temperatures rise and fall unpredictably. The team also received an additional $100,000 from the tree fruit growers of Washington state through the Washington Tree Fruit Research Commission to partially fund field trails in support of the technology.

The unique nanocrystal solution was formulated by Xiao Zhang, associate professor at ���سԹ�’ Bioproducts, Sciences and Engineering Laboratory, and a team of collaborators representing multiple disciplines.

“Frost damage happens in spring, as the flowers open and the sensitive tissues in the plant are exposed,” said Matthew Whiting, scientist and professor of horticulture at WSU’s Irrigated Agriculture Research and Extension Center. “If we get a warm week, it signals to the plant that it needs to wake up.

“But plants lose their tolerance to the cold quite quickly, and that’s when we see frost damage,” Whiting added. “You see a lot of crop damage as a result.”

Positive results with preliminary trials

The team, led by professor Qin Zhang, director of WSU’s Center for Precision and Automated Agricultural Systems, also includes Xiao Zhang, Matthew Whiting, and Changki Mo, ���سԹ� associate professor of mechanical engineering. Together they conducted their first field trial with the nanocrystals this spring. It showed positive results.

The team will continue the trials over the next three years, seeking to perfect the dosage and application strategy, in addition to the nanocrystal technology.

“We will explore thermal properties of the nanocrystal spray, and focus on fully understanding the mechanism of nanocrystals in frost damage reduction,” Mo said.

If it proves feasible, the technology could have a large impact on the agriculture industry.

“Our preliminary results show the technology to be very promising, even better than we were expecting,” Qin Zhang said. “If we prove that the technology works, and if the method of application is perfected, it will not only have applications in tree fruit, but in many other crops, and beyond. The potential for this technology is huge.”

Unique and renewable characteristics

Since the nanocrystals are made from plant-based material, they represent a more environmentally friendly method for controlling temperatures for crops than current techniques.

Currently, growers use methods such as wind turbines to circulate air and raise the temperature of cold pockets in orchards. Or, they use heaters that cost upwards of thousands of dollars per night, which also give off significant pollution.

“With these unique structural characteristics and physical properties, and the fact that the nanocrystals are all made out of biobased materials and are considered renewable, we are identifying a high-value niche application for tree fruit and frost prevention and protection,” Xiao Zhang said.

Cross disciplines for the future of fruit protection

Researchers from across several disciplines at WSU are working to perfect the nanocrystal method, ensuring a quality product built for industry use, Qin Zhang said.

“No single person who works in chemical engineering and nanocrystal technology, horticulture, mechanical engineering or precision agriculture has complete knowledge on the subject,” Qin Zhang said. “It is truly a transdisciplinary team. Everyone provides expertise in their particular field. This integrated team is covering all knowledge to conduct this research.”

 

Contacts:

• Qin Zhang, director and professor at WSU’s Center for Precision and Automated Agricultural Systems, 509-786-9360,��qinzhang@wsu.edu
• Xiao Zhang, associate professor at Voiland School of Chemical Engineering and Bioengineering, 509-372-7647,��x.zhang@wsu.edu
• Changki Mo, ���سԹ� associate professor of mechanical engineering, 509-372-7296,��changki.mo@wsu.edu
• Matt Whiting, scientist and professor of horticulture at WSU’s Irrigated Agriculture Research and Extension Center, 509-786-9260,��mdwhiting@wsu.edu
• Maegan Murray, ���سԹ� public relations specialist, 509-372-7333,��maegan_murray@wsu.edu