A network of U.S. scientists is intensifying efforts to develop more climate-resilient apple trees as increasingly volatile weather patterns threaten orchards across major fruit-growing regions, raising concerns about long-term risks to an industry that generates roughly $23 billion in annual economic activity.

Researchers at Cornell University, the United States Department of Agriculture and several partner institutions are focusing on rootstocks, the underground foundation of commercial apple trees that influences growth, productivity and resistance to environmental stress.

The work has gained urgency since a series of severe temperature swings damaged orchards in the northeastern United States in 2015, an event that some researchers later linked to a phenomenon known as “rapid apple decline.”

Terence Robinson, a horticulture professor at Cornell University, recalled how unusually warm temperatures in February 2015 were followed by a sharp cold snap that swept through New York and into fruit-growing regions of Pennsylvania.“We got a warm-up in February, and then a big cold air mass moved into New York and pushed all the way down into the fruit-growing area of Pennsylvania,” Robinson said.

“In the spring, we started seeing tree damage.”Scientists concluded that the rapid temperature drop, estimated at as much as 65 degrees Fahrenheit within days, disrupted trees that had already begun emerging from winter dormancy. Researchers found particularly severe damage in rootstocks rather than trunks or branches.

The findings drew attention to vulnerabilities in some of the apple industry’s most widely used rootstocks, including the M9 variety developed more than a century ago at England’s East Malling Research Station.Commercial apple trees are typically produced through grafting, a process that combines two different plants.

The upper fruit-bearing portion, known as the scion, comes from commercial varieties such as Gala or Red Delicious. That section is attached to a separate rootstock selected for characteristics including tree size, productivity and disease resistance.

Because rootstocks determine how trees absorb water, respond to stress and tolerate environmental conditions, scientists increasingly view them as central to protecting orchards from climate-related disruptions.Robinson and USDA scientist Gennaro Fazio jointly oversee the Geneva Apple Rootstock Breeding Program, based in Geneva, New York.

The initiative, operated by Cornell University and the USDA, is the only commercial apple rootstock breeding effort in North America focused on developing new foundations for orchards.Since 1968, researchers in the program have crossed and evaluated thousands of apple rootstocks.

Early efforts concentrated largely on disease resistance, particularly protection against fire blight, a destructive bacterial disease affecting apple and pear trees.More recently, researchers have expanded their priorities to include drought tolerance, resistance to high-salinity soils and improved survival during unstable winter conditions.

“We still continue wanting to have a rootstock that is dwarfing, because dwarf orchards are much more profitable, and that produces early,” Robinson said. “We have broadened our list of goals for this program to include drought resistance, tolerance of high-salt-content soils and the ability to withstand more moderate winters.”The process is lengthy.

Developing a commercial rootstock can take decades because scientists must cross parent trees, evaluate offspring for desirable characteristics and test performance across multiple climates and growing conditions.Cornell released its first commercial rootstock in 1997, nearly three decades after the program began.

Some varieties introduced in 2023 originated from genetic crosses first made during the 1970s.“It requires long-term commitment to learn to love apple rootstocks,” Robinson said.Researchers say the challenge has become more complicated because climate variability is increasing faster than orchard replacement cycles.

Apple orchards are typically expected to remain productive for 15 to 30 years, meaning growers must make planting decisions without knowing exactly how weather patterns may evolve over the lifespan of their trees.

Lee Kalcsits, a professor of tree fruit physiology at Washington State University, leads the Strengthening Pear and Apple Resistance to Climate project, known as Sparc, a national research collaboration studying how extreme weather affects fruit trees.

Kalcsits said breeding efforts should prioritize adaptability rather than designing trees for one specific future climate scenario.“We need to be mindful that the rootstocks we select are adaptable,” he said. “It’s not that they’re adapted to a future climate, but that they’re adaptable.”Research published by Kalcsits and colleagues in 2024 found that both fall and spring temperatures are warming in major U.S. apple-growing regions.

Warmer conditions can interfere with the chilling requirements apple trees need before flowering and can also cause trees to leave dormancy earlier, increasing exposure to damaging cold events.Scientists say abrupt winter fluctuations have become a growing concern as climate-driven disruptions to atmospheric circulation allow Arctic air masses to move farther south into the United States.

Robinson said damaging cold snaps have struck major apple-producing areas, including southern Pennsylvania and western Michigan, four times since 2015.Rootstocks can influence how trees respond to those conditions by affecting dormancy timing, cold tolerance and water use.

Some newer rootstocks developed through the Geneva program have shown reduced damage during false springs followed by hard freezes compared with older standards such as M9.Researchers are also turning to wild apple populations from central Asia, where domesticated apples originated, to expand genetic diversity and identify additional stress-resistance traits.

Experimental rootstocks are tested nationwide through a research collaboration known as NC-140, which evaluates orchard performance across multiple states. One test site operates at North Carolina State University’s Mountain Horticultural Crops Research Station near Asheville.

Mike Parker, a tree fruit extension specialist at North Carolina State University, said scientists monitor survival rates, trunk growth, fruit size and yields over many years before recommending new rootstocks to commercial growers.“When we put the replicated trials in multiple states, there’s things that we find out real quick, like that this rootstock is a dog and ain’t going to fly,” Parker said.

“We would much rather kill trees at our research station than have growers lose trees on their farm.”Parker has overseen the university’s rootstock evaluations since 1996 and, like Robinson, is approaching retirement.

Robinson said he is concerned that long-term agricultural breeding programs may struggle to attract younger researchers, many of whom prefer working on commercially visible fruit varieties rather than root systems that can take decades to develop.

He also expressed concern that funding agencies could eventually scale back support for long-duration breeding programs if policymakers conclude that existing rootstocks are sufficient for current industry needs.“I fear that they’ll say: ‘We have enough rootstocks, let’s just close down this effort,’” Robinson said.

“And for things that we’re facing right now, we probably have a good series of rootstocks available. But it’s these emerging problems, that you don’t really think of or didn’t plan for, that you might not be able to respond to if they shut down the program.”

Brazilian researchers are developing new coffee hybrids by blending genetic material from rare and non-commercial species in an effort to protect global arabica production from the growing impact of climate change.

At the Campinas Agronomy Institute in São Paulo state, agronomist Oliveiro Guerreiro Filho tends to a diverse collection of coffee plants that contrasts sharply with the uniform plantations typical of Brazil’s commercial farms. The experimental plots include about 15 lesser-known species such as racemosa, liberica and stenophylla, each offering genetic traits that scientists hope can strengthen the resilience of arabica, the world’s most widely consumed coffee variety.”

Researchers warn that arabica crops are particularly vulnerable to rising temperatures and shifting weather patterns. A report released this week by Rabobank said climate change could render about 20% of current arabica-growing areas unsuitable by 2050, with Brazil, the world’s largest producer, expected to see declining output.

To address these risks, scientists are attempting to introduce hardier genetic traits from wild and underutilized species into arabica plants. The goal is to develop hybrids that can withstand drought, heat, pests and diseases while maintaining the flavor and yield characteristics that make arabica dominant in global markets.“We’ve been working at the institute for many years to transfer drought tolerance genes from the racemosa species to arabica,” Guerreiro Filho said. “We’re trying to create drought-tolerant arabica varieties.

The process is complex and time-intensive. Researchers must cross-breed different species, cultivate hybrid plants, and subject them to harsh environmental conditions to identify those with the strongest resilience. Guerreiro Filho said the full development cycle can take between 20 and 30 years before a viable variety is ready for commercial use.

Some of the traits being targeted are already evident in the wild species. Liberica, for example, has drawn attention from farmers in Southeast Asia for its ability to tolerate high temperatures and dry conditions. Small-scale growers in Indonesia and Malaysia have begun cultivating the species experimentally to assess its performance under climate stress.”

Liberica can tolerate heat and high temperature environments very well, and it is disease-resistant,” said Jason Liew, founder of My Liberica, a coffee plantation in Malaysia’s Johor state.

While such characteristics are valuable, liberica and other non-arabica species have limited commercial appeal due to lower yields or different flavor profiles. Brazilian researchers are therefore focused on transferring these beneficial traits into arabica, rather than replacing it entirely.

Early results from hybridization efforts suggest potential gains in both resilience and crop protection. Arabica plants cross-bred with liberica have shown increased resistance to coffee rust, a fungal disease that has devastated crops in several producing regions. Meanwhile, hybrids incorporating racemosa genetics appear better able to withstand attacks from coffee leaf miner larvae, a common agricultural pest.

Scientists say these advances are critical given arabica’s narrow genetic base, which limits its natural ability to adapt to environmental changes. Expanding that genetic diversity is seen as a key strategy for sustaining long-term production.“Working with alternative species of coffee is vital because arabica has an extremely narrow genetic base,” said Rodolfo Oliveira, head of the coffee unit at Brazil’s state research agency Embrapa. “This makes it highly vulnerable to pests, diseases, and climate change.

”The research also reflects broader shifts in the global coffee sector, where producers are increasingly grappling with the economic and environmental consequences of climate volatility. Reduced yields, rising production costs and shifting cultivation zones are already affecting supply chains, with implications for prices and market stability.

Brazil’s efforts to develop more resilient coffee varieties may play a central role in shaping the future of the industry. As the leading global producer and exporter, changes in its output have significant ripple effects across international markets.

At the same time, the long timelines required for developing new hybrids mean that current research will only begin to deliver results years from now. Until then, farmers remain exposed to immediate climate risks, underscoring the urgency of both scientific innovation and adaptive farming practices.

The conference, titled “World of Dates,” will be held from Nov. 25 to Dec. 4 and will bring together specialists from around the world to exchange knowledge and explore solutions for long-term agricultural development.

Organized by the National Center for Palms and Dates at King Saud University, the event returns this year with expanded scientific and commercial programs.

It includes a partnership with King Abdullah University of Science and Technology, strengthening the event’s focus on cutting-edge research, food security strategies and future investment opportunities.

The conference carries the theme “Investment and Innovation to Explore New Horizons for the Palm and Date Sector,” highlighting the sector’s strategic value for both national and international markets.

Sessions will explore the latest advancements in agritech, sustainable farming practices and digital transformation in agricultural management.

Central discussions will address challenges linked to palm pests and diseases, bringing global experts together to present new research and practical solutions.

The program will also emphasize the role of smart farming technologies, including precision systems, data-driven irrigation and automated monitoring tools that can boost productivity and improve overall quality.

Post-harvest automation will be a major focus of the event, with speakers highlighting ways to optimize processing, reduce waste and enhance efficiency.

Innovation in sorting, packaging and preservation technologies will be presented as essential steps toward strengthening the circular economy within the date industry.

A number of pioneering research studies and development initiatives will be showcased, including those nominated for the National Center for Palms and Dates Award.

These contributions are expected to highlight progress in biotechnology, sustainable practices and environmental resilience for palm cultivation.

The exhibition component will be open to the public free of charge from 4–11 p.m. daily, offering visitors a comprehensive experience through region-themed pavilions that showcase the Kingdom’s diverse date varieties and cultural heritage.

Each pavilion will highlight regional identities, farming traditions and agricultural techniques that have shaped the sector over generations.

An independent exhibitors’ area will provide space for companies, farmers and entrepreneurs to present processed date products, new technologies and market innovations.
A live-cooking zone supervised by Saudi and international chefs will allow visitors to experience culinary creations centered around dates.

The event will also feature a dedicated restaurant and cafe area serving local and international dishes made with Saudi dates, reflecting their rising global appeal.
A handicrafts area will display products and artwork connected to palms and dates, shining a spotlight on the deep cultural ties embedded in the sector.

Visitors can explore the Palm Heritage Museum, an immersive experience that traces the history of palm cultivation and the evolution of the date industry.

The museum highlights traditional practices, technological advancements and the significant role dates have played in social and economic development.

Saudi Arabia continues to strengthen its position as a global leader in the date market.
In 2024, the Kingdom ranked first in global date exports, reaching 133 countries and achieving export values of SR1.695 billion ($452 million) with production exceeding 1.9 million tonnes.

The conference aims to build on this momentum by exploring global partnerships, enhancing investment opportunities and promoting sustainable practices across the entire value chain.

With its focus on innovation and collaboration, the event is expected to support long-term growth and reaffirm the Kingdom’s global leadership in the date industry.