California Fruit and Vegetable

Tag: Washington State University

  • Protecting Apples & Pears in Extreme Temperatures

    Washington State University (WSU) scientists will lead nationwide research addressing the impact of extreme temperatures on apple and pear crops.

    Lee Kalcsits, associate professor and Endowed Chair of Environmental Physiology for Tree Fruit, heads a team of 21 scientists from seven institutions working to mitigate stresses on pome fruits and develop strategies that limit future risks.

    “This is a great team that will share existing knowledge and develop new ideas to support apple and pear growers dealing with extreme temperatures,” Kalcsits said.

    Funded by the USDA National Institute of Food and Agriculture’s Specialty Crop Research Initiative, the $6.75 million project will run for four years.

    Among research goals, the team will focus on extreme cold and heat, studying a variety of issues including cold hardiness patterns for new apple and pear cultivars; flowering and the emergence from dormancy during spring; and how to mitigate sunburn and enhance red color during extreme heat.

    “In Washington state we typically deal less with cold stress, but in 2023 and 2024 we had higher losses than normal due to cold,” said Kalcsits, an associate professor of horticulture based at WSU’s Wenatchee Tree Fruit Research and Extension Center(TFREC). “In the eastern U.S., the risk of cold damage is higher, so we can use some knowledge from scientists located there. They aren’t as used to extreme heat on the East Coast, so we can share some of our strategies more easily with them, thanks to this project.”

    Economists on the team, including a climate change economist, will collaborate with other specialists to examine the current risk of extreme climate issues, study historic impacts of extreme temperatures, and create models that will allow growers to more reliably assess risk.

    Team members will also look at the cost and benefit of different mitigation strategies to see if they’re worth the cost of implementation.

    Finally, the team aims to develop a coordinated, nationwide Extension strategy for mitigating fruit losses. Researchers plan to host a series of field days and fruit schools online and in person to provide growers with training that helps reduce losses due to temperature extremes.

    “When you look at the statistics, extreme temperatures are the leading cause of reductions in yield and packout,” Kalcsits said. “Even with our current strategies, losses occur. We need to develop a better understanding of the biological factors leading to those losses, and growers also need more effective options.”

    The project’s overarching objective is to make more apples and pears available for consumers.

    “It’s about developing new strategies for issues the industry already experiences,” Kalcsits said. “It’s not just climate change but understanding exposure to extreme temperatures and how that will change in the future. It will be great to have additional tools available now and to understand risks 20 or 50 years down the road.”

    Other WSU scientists on the project include WSU Pome Fruit Breeder Kate Evans; Biological Systems Engineering Assistant Professor Kirti Rajagopalan; School of Electrical Engineering and Computer Science faculty members Ananth Kalyanaraman and Paola Pesantez-Cabrera; and Sonia Hall, researcher at WSU’s Center for Sustaining Agriculture and Natural Resources.

    Other institutions involved in this project include Cornell University; the University of Maine; Michigan State University; Penn State University; Oregon State University; and the USDA Agricultural Research Service.

  • Researcher Enhances Tree-Pruning Robot

    Martin Churuvija partnered with Australian researchers this summer to integrate artificial intelligence (AI) into his prototype tree-pruning robot. The Washington State University (WSU) biological systems engineering PhD student had the opportunity to work with scientists at the University of Technology Sydney (UTS) thanks to a partnership between WSU and the Australian university focused on robotics.

    He spent two months in Sydney this summer working with UTS experts to figure out how to get his robot’s operating system to recognize and accommodate deformations in apple trees, which can affect how the trees are pruned.

    Under the advisement of UTS Professor Alen Alempijevic, Churuvija updated the operating system of his robot to the latest software, enabling it to work with a newer camera system. Churuvija said the algorithms developed by UTS help his robot accommodate for minor tree movements while it scans.

    Alempijevic said Churuvija had great technical abilities and was pleased to see the research start to make inroads into agriculture automation.

    “Working together with Martin, and WSU, allows us to develop systems more rapidly,” Alempijevic said. “Being in opposite hemispheres — UTS in Australia, WSU in the USA — has the advantage of more deployment opportunities which are critical to increasing the robustness of systems.”

    Churuvija’s original system assumed a static tree structure — which worked in a controlled lab environment at the Irrigated Agriculture Research Extension Center in Prosser. Occasionally though, scans in the orchard would show odd, 3D pictures of a tree branch in a cone shape due to the wind disturbing a scan. Adding AI elements helps the robot piece together missing information and brings it closer to real-world development.

    “Using robots in orchard environments is extremely challenging,” Churuvija said. “Unlike indoor settings, outdoor conditions bring a range of obstacles. For example, our vision system — which uses cameras to perceive the world in 3D like humans — must recognize tree structures despite inconsistent lighting and wind.”

    Churuvija’s work is still in the research stage, but his ultimate goal is to help develop robots that can pick fruit as well as prune plants. He is currently focused on finalizing the development of the pruning robot and plans to run trials this winter.

    Churuvija’s trip to Australia wasn’t solely centered on lab time. He got to visit several Sydney landmarks such as the opera house and the zoo. Even though it’s on the other side of the globe from his lab in Prosser, Sydney felt comfortable, and it reminded Churuvija of his home city of Buenos Aires, Argentina.

    “Luckily the weather is similar to the weather from the place where I have lived the most,” he said. “It’s a big city so I got to interact with people from all over the place and visit the iconic places.” — By Tom Holm, Washington State University

  • Filling in the Blanks About Rose Stem Girdler in Caneberries

    Berry farmers are all too familiar with the rose stem girdler (RSG), an invasive insect from Eurasia that came to North America over a hundred years ago. They know that the copper-colored beetle has migrated to the Pacific Northwest. They know it attacks caneberries — blackberries and raspberries — sometimes ravaging up to 90% of a crop and forcing farmers to replant fields.

    What they may not know is when or where it will strike or how to contain it.

    Now, however, researchers at Washington State University (WSU) may be on the verge of providing a breakthrough by developing a coordinated approach to control RSG; an approach known as integrated pest management. The project was funded by the Northwest Center for Small Fruit Research, , an  Agricultural Research Service-led consortium, to gather information about RSG and then develop tools that growers could employ against it.

    According to Justin O’Dea, a WSU regional agriculture specialist, one such tool is a pest emergence model that will help farmers precisely time their insecticide sprays to be most effective. The model helps predict when RSG, which overwinter as larvae inside the stems of berry plants, emerge into the outside world as adult beetles.

    A major concern with controlling RSG is the insect’s innate unpredictability, O’Dea said.

    “Damage from this pest is commonly intermittent and variable, which blindsides berry growers when infestations flare,” he said. “This can lead to growers making ineffective, pre-emptive sprays to try and make sure they are not blindsided again.”

    The recent discovery of a natural predator of RSG — a parasitoid wasp known as Baryscapus rugglesi – is also now in the integrated pest management toolkit, although its efficacy is not yet fully known. Parasitic wasps lay their eggs inside other insect species, killing the host insect in the process. As a result, these wasps are used extensively, worldwide, to control pest insect populations in agriculture.

    An adult rose stem girdler beetle feeds on a blackberry leaf. (Photo by Justin O’Dea, Washington State University)

    “We know now that we have a parasitoid of RSG [in the Pacific Northwest] and have observed periods where RSG appears to decline inexplicably,” O’Dea said. “This phenomena of RSG pest pressure decline may be at least partly due to parasitism. If so, perhaps parasitoids will eventually lead to RSG becoming less of an important threat to caneberries in the Pacific Northwest, but only time and further research will be able to confirm that.”

    In the meantime, or at least until late spring when the emergence model predicts RSG adulthood, O’Dea said there is something that farmers can do to help prevent infestation: prune. This step is important because, after hatching, RSG larvae burrow into the canes where they feed on water, nutrients, and sugars moving through the plant’s vascular system. The larvae will eventually bore into the middle (the pith) of the cane.

    Thoroughly pruning out all canes that show symptoms of RSG damage (cane swelling, wilting, or breakage) can be done at any point before the pest emerges. The damaged canes should be removed from the field and burned.

    “This strategy [is] part of an effective integrated pest management program,” O’Dea said. “Research in Utah found this method to be about 80% effective. When combined with insecticides, RSG control could be as high as 98%.”

    Successful development of an integrated pest management program for RSG means that growers will have a better chance at minimizing the need for insecticide applications, O’Dea said. That equates to reduced time, energy, and money spent on ineffective and unnecessary insecticide applications, as well as reduced risk to pollinators and other inadvertent impacts to the environment.

    “Based on historical records of how RSG has played out in other regions of the country and our own observations, I’m cautiously hopeful that it will become a limited threat in the long run,” O’Dea said. — By Scott Elliott and Jan Suszkiw, USDA-ARS Office of Communications

  • Grant Aims for Smarter Apple Harvesting

    Researchers have been awarded a $1.2 million National Science Foundation grant to improve the efficiency of automated apple harvesting robotics. Led by Ming Luo, Flaherty assistant professor in the School of Mechanical and Materials Engineering at Washington State University (WSU), the interdisciplinary team of researchers will develop a cyber-physical system that aims to integrate human intelligence and machine learning, enhance decision-making and actuation, and improve picking efficiency. The team includes Yan Yan from computer science, Manoj Karkee from biological systems engineering, Matthew Whiting from horticulture and landscape architecture, and graduate students Ryan Dorosh and Christopher Ninatanta.

    Agricultural robotic technologies currently are inefficient for orchard operations because of the unpredictable environment there as compared to industrial settings, said Luo.

    As part of the 3-year project, the researchers will create a network for human-robot interaction. The network will enable robots to function effectively in farm fields, allowing users to remotely monitor and guide the robots in addressing challenging tasks through teleoperation. Additionally, the robots will learn from the user’s input to enhance their harvesting efficiency.

    The researchers are developing a simple, low-cost robot system with a soft body and a fabric arm. The design is intended to delicately harvest apples without causing damage to the trees, while also allowing the robot to respond quickly.

    “Safety is a concern because the robot might accidentally collide with the tree,” said Luo. “Rigid robots require time to calculate the optimal path for apple picking with minimal damage, which is time-consuming. Therefore, we designed a soft robot that ensures safety in human-robot interactions and is also gentler on the trees. This reduces the computation time required for obstacle avoidance.”

    The robot will eventually automatically help with other operations, like flower thinning, pollination, and pruning as well. — By Tina Hilding, Washington State University

  • New Apple Variety Blends Honeycrisp, Cripps Pink

    Washington State University’s newest apple variety, WA 64, is a sweet, tart, firmly crisp hybrid of Honeycrisp and Cripps Pink, a variety that includes the well-known Pink Lady®.

    Officially released for commercial licensing this summer, WA 64 is expected to reach stores in 2029. WSU will select a partner in the coming weeks to make trees available to growers, and the college will choose a brand name for the new apple in 2024.

    “With WA 64, we’re hoping to fill a useful space in the apple market,” said Jeremy Tamsen, director of innovation and commercialization for WSU’s College of Agricultural, Human, and Natural Resource Sciences.

    Jeremy Tamsen

    Crossed in 1998, WA 64 was chosen for its outstanding eating and storing qualities. Featuring a pink blush over a yellow background, it is slightly less hard but crisper and juicier than its Cripps Pink parent.

    “In its bite, it’s more akin to Cripps Pink than Honeycrisp,” said Kate Evans, professor and WSU apple breeder. “In consumer taste-tests, people have preferred its texture to Cripps. It’s crisper than Cripps Pink.”

    WA 64 maintains that crisp texture after months in cold storage. Like WSU’s successful WA 38 variety, also known as Cosmic Crisp®, it’s self-thinning, meaning growers don’t have to invest as much labor in thinning fruit. It also has high packout, ensuring that apples aren’t tossed for bruising or punctures before they reach the grocery store. WA 64 is harvested at about the same time as Golden Delicious, giving growers of that apple a fresh alternative.

    Kate Evans

    “The main focus of our breeding program is to provide new and improved apples that appeal to consumers and work for the Washington apple industry,” Evans said.

    The timing of harvesting should also appeal to growers, Tamsen said.

    “It makes sense for the industry to have an apple that falls within the Golden Delicious harvest window, with qualities that consumers want right now,” he said. “We think apple buyers will love it.”

    WA 64’s number comes from the fact that it’s the WSU breeding program’s 64th apple to move into the second phase of a three-phase process of selection.

    In the first phase, a single new hybrid is evaluated for fruit quality alongside as many as 15,000 other unique individuals. By the second phase, that large group has been winnowed down to about 50 different individuals, compared in groups of five trees. By the third phase, only a handful of finalists are left, compared in groups of 50 trees.

    “With more and more trees, we get more fruit to fully evaluate,” Evans said.

    Each phase takes several years to complete, so it can take decades for a new hybrid to emerge as a release candidate. The decision on how to move forward is made by a committee of growers and scientists, who weigh whether a new apple can find a useful place in the Washington fruit industry.

    Each WA 64 tree is a clone, reproduced through cuttings, with fruit-bearing budwood, or scions, grafted onto different rootstocks. Each scion is genetically identical to the original mother tree seedling.

    With specialty crop funding from the Washington State Department of Agriculture, WSU scientists have been studying how WA 64 performs on different rootstocks and orchard systems. Plantings were made in 2022 at WSU’s Roza Orchard at Prosser and the Sunrise Research Orchard near Wenatchee. Some Washington nurseries have already begun growing WA 64 budwood to support future expansion.

    “We’re starting with a small amount of budwood,” Tamsen said. “Part of what we’re looking for in a licensee is someone who can scale that up at nurseries so that commercial growers can buy trees. That supply doesn’t exist today, and it can take years to scale it up.”

    WA 64 is the fourth WSU apple to be officially released. WA 38, branded as Cosmic Crisp®, was released in 2013, reaching consumers in 2019. WA 2, a cross of Splendour and Gala, branded as Sunrise Magic®, was released in 2010. WA 5, a cross of Splendour and a variety called Co‑op 15, was released in 2009.

    WA 64’s debut likely won’t be in the same scale as Cosmic Crisp®, which was one of the largest and fastest commercial plant releases ever. Last fall, Cosmic Crisp® joined the ranks of the top ten best-selling U.S. apple varieties by sales and volume.

    Sliced WA 64 apples show the newly released variety’s yellow-pink skin and white interior.

    Tamsen expects fresh, creative ideas to flow from the new apple’s naming process, which could involve WSU community input as well as focus-group sessions. “Apples aren’t one-size-fits-all,” Evans said. “Different consumers have different preferences. Isn’t it wonderful that we can release WSU varieties that meet more of those different preferences?” — By Seth Truscott, College of Agricultural, Human & Natural Resource Sciences, Washington State University

  • Bringing Japanese Melon Varieties to the US

    The experimental fields of the Mount Vernon Northwestern Research & Extension Center are adorned this summer with Japanese melons that could one day fill the displays of grocery stores across the western United States.

    Eight varieties of Higo Green melon — a variation traditionally unique to Japan — are being evaluated at the Washington State University facility for their ability to grow in the Northwest as well as for their sweetness and texture compared to the market-standard variety of cantaloupe. This year’s melon trials follow up on experiments done last summer in which eight melon varieties were compared by size, texture, color and taste.

    After its flagship Higo Green melons came out on top in the eyes of tasters last summer, the Matsui Seed Co. Ltd. opted to further understand how long it would take for fruit of the new varieties to reach maturity in the northwest region of the U.S. and how they compare to other melons commonly found in grocery stores along the West Coast.

    The Matsui Seed Co. didn’t just stumble upon WSU as a partner for these trials. Its president, Kunihiko Matsui, is a WSU graduate who was passionate about working with his alma mater to help introduce new varieties to the U.S.

    “I really appreciate my time at Washington State University, as well as the experiences I had in Washington State and the United States,” Matsui said. “Without those experiences, I wouldn’t be here today.”

    From banker to melon breeder

    Matsui was born into a family with nine generations of agriculture experience in Japan’s Nara Prefecture. His grandfather, Kiichi Matsui, started the Matsui Seed Co. in 1952, driven by a passion for helping his country rebuild after World War II.

    While growing up, Matsui was often asked to review different varieties of melon being grown by his family, an experience that continues to pay dividends now as the president of the company, he said. It’s now Matsui’s children delivering their assessments of his company’s newest melon varieties.

    Prior to coming to the Palouse, Matsui graduated from Japan’s Chuo University with a degree in business. But after four years working at a major bank, he knew he wanted to do something different with his life.

    “When I was at the bank, some of my customers were fresh food delivery companies who distributed, watermelons and melons created by my father,” Matsui said. “I realized that this was my father’s product and our family’s business was producing the seeds for new varieties of melon. Just as my father transferred these new varieties through selling seeds to distributors, my father’s thoughts and philosophies were transferred to me, and I understand just what an amazing job this could be.”

    Matsui first traveled to Washington after joining an international program during his time as a university student, staying for one month with a host family in Snohomish County. Impressed by the weather and the people he encountered as well as WSU’s reputation as an agriculture school, Matsui left his job and traveled to the U.S.

    In the fall of 2002, Matsui enrolled at WSU’s Intensive American Language Center. He opted to study crop sciences and graduated with his bachelor’s degree in 2005. Steve Ullrich, an emeritus Crop and Soil Sciences faculty member, was instrumental in Matsui’s studies and path forward after graduation.

    “Just before I left the U.S., he told me that I should study from my father because even though I have the basic breeding knowledge, there is more to learn from my father,” Matsui said.

    The path back to Washington

    Upon returning to Japan, Matsui began working closely with his father as part of the seed company. The next several years were spent gaining insight on the complex and lengthy breeding process for different melon varieties. In Japan, melons are grown twice a year. Initially, Matsui said his knowledge of breeding better melons was lacking, and amounted to little more than growing and harvesting melons before cutting them up and tasting them.

    Eventually, Matsui’s father introduced him to a product development expert, who gave him clues on the key components to breeding better melons. Once he understood the balance of genetic and environmental factors, his eyes were opened to the possibilities.

    While in the United States, Matsui would often visit local farmer’s markets across the Palouse. The local farmer’s penchant for growing different kinds of crops not as commonly available in big grocery stores demonstrated that there was a wiliness among growers to try new things. Additionally, Matsui came to believe that American consumers are quite eager to try new things if they are available to them.

    These factors brought Matsui to pursue a path to bringing Japanese melon varieties to the United States. When it came to finding a partner to find out which types of melons grew best, he turned to his alma mater.

    “Washington is very close to the climate of northern japan, a similar climate,” Matsui said. “I know that there are places that are warmer and therefore better to grow, but I didn’t have connections in those places like I did in Washington and I wanted to use the connections I had to WSU.”

    Carol Miles, director of the WSU Mount Vernon Northwestern Washington Research and Extension Center (WSU NWREC), recalls telling Matsui about the challenges posed by doing melon trials at the Mount Vernon site.

    “The soil is quite a bit heavier here than eastern Washington, spring rains can cause planting delays, and soil and air temperatures are cooler, leading to melons taking much longer to reach maturity,” Miles said.

    Despite these challenges, Matsui wanted to press ahead, impressing Miles with his affinity toward the university.

    Srijana Shrestha is a Ph.D. gradate research assistant with Miles at WSU NWREC and leads the trials involving Matsui melons. On approximately a tenth of an acre, melon trials are conducted during the summer months, with last year being the first to include seeds provided by Matsui’s company.

    While Matsui’s melons took roughly 20% longer to reach maturity than Athena cantaloupe, a market standard, when they did, the resulting fruit were the highest rated by taste testers for their firmness and sweetness. To generate greater reliability in the results and drill down further into which type of melon is best for the western U.S., Shrestha is repeating the trials again this year with eight varieties of Higo Green melons, testing them against a new market standard variety, Infinite Gold.

    “Matsui  wants to test their best varieties for the U.S. because the plants perform very differently in Japan, and so it’s a matter of understanding how they grow here and how are they compare to varieties standard to American consumers,” Shrestha said.

    Once Americans taste the unique melon varieties of Japan, Matsui is confident they’ll come back for more.

    “Even though our varieties aren’t common commercially in the U.S., I believe the taste will be accepted in the U.S.,” Matsui said, “The taste will break through the market.” — By RJ Wolcott, Washington State University

  • WSU Soil Researchers Seed long-term Projects

    Washington State University — Professor and Washington State University Extension Agent Chris Benedict is partnering with colleagues at the Center for Sustaining Agriculture and Natural Resources (CSANR) to lead the state forward on soil research, outreach, and best practices.

    Their work improving soil health and productivity helps guide the efforts of agricultural industries, environmental constituents, and non-governmental organizations (NGOs) to protect Washington’s environment while boosting the state’s food supply and economy.

    “Improving soil health is universally accepted,” Benedict said. “There are few issues where so many stakeholders come together and readily agree.”

    In 2018, the Washington State Legislature provided funding to develop long-term agroecological research and Extension (LTARE) sites across Washington state, with the first located at WSU’s Northwestern Washington Research & Extension Center at Mount Vernon.

    WSU, the Washington State Department of Agriculture, and the Washington State Conservation Commission are working closely together to spearhead this tri-agency WaSHI effort.

    Currently, the USDA runs 18 long-term agroecological research sites throughout the U.S. With the addition of six new Washington sites (including Mount Vernon), all managed by WSU, the state is now poised to account for a quarter of all sites nationwide.

    “These sites will drive our knowledge,” Benedict said. “The experimental treatments are based on feedback from various industries. Most agricultural research usually spans 3 to 5 years, but we expect this research to provide the first insights in 5 to 10 at the earliest, depending on the production system and treatments involved.”

    Moreover, these LTARE sites focus on several of the state’s most productive agricultural systems and commodities, including dryland agriculture in eastern Washington, irrigated production in the Columbia Basin, wine grapes, tree fruit, western Washington diversified farming, and northwestern Washington potato.

    Research at the LTARE sites will be guided by the already developed Washington Soil Health Initiative Roadmap.

    “The roadmap identifies where we are currently in our knowledge of soil health and the main problems, then lays out our future goals, objectives, and milestones,” Benedict said.

    That’s important because it’s a first in Washington.

    “Imagine you’d never been to the doctor and suddenly you get your first bill of health — we will essentially be creating the first ever ‘bill of health’ for Washington soils,” Benedict said.

  • Invasive Stink Bug Habitat Could Expand with Climate Change

    A foul-smelling, voracious, wide-spread pest of fresh fruits and tree nuts could become even more ubiquitous with climate change.

    A recent modelling study found that changing weather could increase suitable habitat for the brown marmorated stink bug in the United States by 70%. The study, published in Pest Management Science, draws on data from a three-year stink bug monitoring effort in 17 states as well as several potential climate scenarios. However, whether the insects will thrive in new places depends on the conditions of each area and potential mitigation measures.

    “Every system will change with climate change, so the fact that you can grow garbanzo beans, lentils or wheat without these pests now, doesn’t mean that you will not have them in a few years,” said study lead author Javier Gutierrez Illan, a Washington State University entomologist. “There are mitigating things that we can do, but it is wise to prepare for change.”

    The study found that overall, there is likely to be a northward shift in stink bug-friendly conditions. Regions that may be particularly affected include the Mid-Atlantic, areas surrounding the Great Lakes, and the valleys of the West Coast, such as the Sacramento Valley in California and the Treasure Valley in Idaho.

    The brown marmorated stink bug is a generalist herbivore — it is known to feast on nearly 170 different plants including crops and ornamental plants. Originating in Asia, this type of stink bug first appeared in the U.S. about 20 years ago and has since spread coast to coast. It’s been detected in 46 states and considered a pest in 15 of them.

    Brown marmorated stink bug on a blackberry plant. Photo by Gheorhge on iStock

    Homeowners may recognize brown marmorated stink bugs because they like to overwinter indoors. In fact, the study found that proximity to populated areas appeared to help the insects get established in new places, but once there, they did not need to be near people to proliferate. Other factors like availability of water mattered more for their abundance.

    People are likely inadvertently transporting stink bugs in vehicles or farm equipment to areas that would otherwise be hard for them to reach by flying alone, said Gutierrez Illan.

    Stink bugs dislike cold winters, but the rising temperatures brought by climate change are not necessarily a good thing if the land becomes too dry. They need water, so the researchers said that changing patterns of precipitation will likely influence where the stink bugs will thrive.

    In some states including Washington, officials and researchers are employing a parasitoid insect, called the samurai wasp, to control stink bugs. The wasps lay their own eggs inside stink bug eggs. This not only destroys the affected eggs, but when the wasp larvae hatch, they eat other developing stink bugs. Measures like these might help prevent or minimize stink bug spread into new areas, Gutierrez Illan said.

    For Washington growers, the researcher recommended using WSU’s DAS, or Decision Aid System, a web-based tool which provides information to help prepare for changes to their agricultural systems, including the possible appearance of these pests.

    Gutierrez Illan also advised growers to familiarize themselves with the brown marmorated stink bug through sites like stopbsmb.org, even if they have never had the pest in their fields.

    “Most growers learn from their parents or from the previous generation, but the information that they had is probably no longer as useful because the climate is changing, so they need these types of tools,” Gutierrez Illan said.  — By Sara Zaske, Washington State University

  • New Grant Aims to Reduce Plastic Taken From Fields to Landfills

    Washington State University is leading a new project that aims to advance soil-biodegradable mulches and develop innovative methods for recycling the plastic. The projects is funded by a $8 million, four-year Specialty Crop Research Initiative grant from the USDA National Institute of Food and Agriculture.

    Growers of crops like strawberries, raspberries, pumpkins, tomatoes, and melons depend on plastic mulch to enhance productivity. But that mulch is rarely recycled, and the soil-biodegradable version isn’t allowed in domestic organic production.

    Consequently, every year an estimated 2.5 million tons of plastic mulch is dumped into landfills, tilled into the soil, or burned, leading to global terrestrial and aquatic pollution. And that number is rising as more growers worldwide adopt plastic mulch without viable, sustainable end-of-life options for waste management.

    The new WSU-led program will focus on strawberries as a model crop because it’s a popular fruit grown throughout the country in different weather situations and soil systems. Scientists, extension specialists, and growers in California, Florida, Nebraska, and Washington will all participate. Companies such as Driscoll’s and Natureripe are also collaborating on the project.

    Plastic mulch is long black plastic strips laid down in fields to suppress weed growth, optimize soil temperatures, reduce water loss, and produce higher yields of clean fruits and vegetables free of soil debris. Its usage leads to significantly reduced herbicide application, fewer crops lost to rot from soil contact, a jump start on the growing season, yield enhancements, and improved profitability.

    “Growers are really dependent on plastic mulch,” said Lisa DeVetter, a Department of Horticulture associate professor based at WSU’s Northwestern Washington Research and Extension Center in Mount Vernon. “Every year, tens of thousands of acres of mulch are put on soil across the country, but the plastic mostly winds up in landfills and takes hundreds of years to degrade.”

    DeVetter, the lead project investigator, has collaborated on plastic mulch solutions for several years, frequently focusing on improving knowledge of soil-biodegradable mulch.

    Lisa DeVetter

    Soil-biodegradable mulch currently can’t be used in organic fields because it contains non-bio-based and synthetic materials forbidden in U.S. certified organic production. Growers are also concerned about its ability to fully biodegrade in soils and the potential long-term economic implications of degraded soil.

    Mulch recycling is a limited option because it’s coated with dirt and plant debris after being removed from the fields.

    “As much as 50 to 80% by weight of the removed mulch is contaminated with debris,” DeVetter said. “Most recycling facilities require less than 5% contamination.”

    The research team will look at methods for removing debris from the plastic and new technologies for recycling debris-laden plastic. They’ll also study ways to build the infrastructure necessary to handle potentially huge volumes of mulch, and how to incentivize more sustainable waste management behavior.

    This is the first time a research project will combine recycling and soil-biodegradable efforts to help reduce the tonnage sent to landfills and the resulting environmental impact; they’ve always been separate studies.

    “We’re leveraging our experience and network of collaborators — researchers, people in the industry, as well as allied nonprofit organizations — to come up with viable solutions to make an impact,” DeVetter said. — By Scott Weybright, College of Agricultural, Human, and Natural Resource Sciences, Washington State University

  • How to Improve Soil Health in Potato Cropping Systems

    Minimizing soil disturbance is one of the key tenets promoted to build soil health in agricultural systems. Many farmers across the county have adopted reduced and no-till systems to build soil carbon, a central component to healthy soils. But what if you grow a crop where the part you sell is underground – like potatoes? What are some options to build soil health in those systems?

    In the US, overall, the potato industry was a $4 billion industry in 2020. Americans will eat their potatoes fresh, frozen, fried, chipped, canned, dehydrated. Potato products are also used as food ingredients, like potato starch.

    Potatoes are a valuable crop in Washington state. We are the second leading producer of potatoes in the United States (after neighboring Idaho.) Central Washington grows Russet potatoes primarily for French fries and other processed potato products. Northwestern Washington is known for colorful, fresh-market potatoes.

    The potato industry in Washington recognizes the importance of healthy soils for long-term, sustainable production of the crop. One issue with growing potatoes: they are a tuber crop, growing belowground. Thus, planting and harvesting them disturbs the soil more than a crop like wheat or barley, which are harvested aboveground. Growers and researchers are working on strategies to promote soil health in this typically high disturbance system.

    Through Washington’s new Soil Health Initiative, my team and collaborators recently set up a long-term rotational experiment to explore some of these strategies in potato-based systems. The strategies represent the typical rotations and soils of the area. The trial is designed with methods that use changing levels of:

    • soil disturbance (i.e., tillage),
    • organic matter inputs,
    • internal (cover crops and residues) and,
    • external (compost).

    This allows us to study multiple soil health principles and how they interact with one another.

    Potatoes in northwestern Washington are typically grown in a particular field every 3-5 years. Soil improvement strategies are really focused on what happens before and after the potato crop.

    One practice many growers are experimenting with is cover cropping. Cover crops are grown between cash crops to provide agroecosystem benefits related to 3 of the 4 main soil health principles: cover the soil, increase diversity, and maximize continuous living roots, which help feed microorganisms in the soil.

    Farmers in the area are using two methods. One is winter cover crops, planted in fall and terminated in spring. The other is multi-year cover crops that are mowed and continuously provide organic carbon inputs to the soil.

    Our cold, wet fall and spring seasons can be a challenge to establishing winter cover crops. This is due to harvesting potatoes through October. But having cover crops between all other rotational crops may still benefit the soil.

    The multi-year cover crop likely provides more soil benefits, but farmers are then missing out on several years of growing a cash crop. Our experiment looks at both cover crop strategies and their effects on soil properties, crop yields, ecosystem benefits, and farm economics.

    We are also studying potato-growing systems that reduce soil disturbance. We’re looking at whether it’s both feasible and beneficial to rotate in wheat or barley planted with no-till seeders. Minimizing soil disturbance between potato crops could improve soil health and future potato yields.

    Ultimately, we need to take a systems approach to improving soil health with potatoes and with any crop. It is not just about one crop. It’s about how the whole cropping system is managed over time. By finding those intervention points to introduce a soil-building practice, we can steadily improve soil health even with underground crops. — By Deirdre Griffin-LaHue, Washington State University