Posts Tagged: climate

NIFA funds $3.8 million project to find climate-resilient pistachio trees

Growers invited to participate in study by sharing their experiences

A multi-state team led by Patrick J. Brown has been awarded nearly $3.8 million over the next four years for a project to improve pistachio production as the industry faces warmer winters and scarcer water.

“We are at this unique point in history where we can do this,” said Brown, an associate professor in the UC Davis Department of Plant Sciences.

The project aims to ensure the industry can thrive in coming decades despite the challenges faced. Growers are invited to participate in the study, sharing what they already are trying in their own fields or supporting any aspect of the project. To discuss the possibilities, contact Brown at pjbrown@ucdavis.edu or (530) 752-4288.

The project includes research to ensure pollination, experiments to calculate irrigation needs amid water shortages, creating tools to improve public breeding programs, developing more efficient harvesting equipment, and economic analyses to ensure future pistachio cultivation is economically rewarding. Researchers hope to offer a guide for growers deciding whether to plant new orchards or remove existing ones.

“The success of California's pistachio industry, which is the top producer of the nuts in the world, has always relied on a strong collaboration between UC researchers and pistachio growers,” said project participant Florent Trouillas, a UC Cooperative Extension specialist in the UC Davis Department of Plant Pathology. “Research efforts must continue to address enduring and new challenges, improve sustainability and ensure the profitability of pistachio farming.”

The tasty, green nuts have blossomed into a $5.2-billion industry in California, thanks to their greater tolerance of dry lands and salty soils. The project aims to further improve their climate resilience by finding a rootstock that can thrive despite growing water scarcity and declining water quality projected over the next half-century. With millions of genetically distinct pistachio trees growing in the state, "we already have out there what may be the industry's next great rootstock," Brown said. "It's probably in some grower's field already. We just have to find it."

Researchers seek to pair that new rootstock with high-yielding scions – the producing part of the tree grafted onto the rootstock – to develop new combinations that can thrive in the different conditions across the state.

Trouble with “boy meets girl”

Pistachios, like many other tree crops, have male and female trees, and they require hundreds of hours of wintertime temperatures below 45 degrees Fahrenheit for the trees to flower in the spring. Wind blows the pollen from male flowers to female flowers, creating nuts.

Complicating the timing: Boy flowers and girl flowers generally require different amounts of winter cold to bloom. After a sufficiently cold winter, boys and girls flower together. But if the winter is warm, most of them will flower at different times, reducing pollination.

That happened in the winter of 2014-15, which saw unusually warm winter temperatures. The following fall, farmers harvested only half their expected crop, losing more than $1 billion, Brown said. Climate change is expected to provoke progressively warmer winters in the future, on average.

An additional complication: The boy scions come from a single variety, or cultivar, and the girl scions come from another single cultivar. "In California part of the problem is that we have been relying on a single male and single female cultivar," Brown explained.

A key part of this project will be to test new scions that can pollinate efficiently despite warmer winters. “We now have additional male and female scions released in the last 10 to 15 years, but we need more information on their chill requirements,” Brown said.

Growing importance of pistachio sector

With nearly 520,000 acres planted in California in 2021, pistachios are the fastest-growing tree nut crop in the state. Growers have doubled their plantings over the past decade, due to pistachios' drought tolerance and higher gross returns compared to other nuts, experts report. California dominates the industry, growing 99 percent of the nation's crop and nearly 60 percent of the world's crop, employing people in 47,000 full-time-equivalent jobs and creating $5.2-billion of total economic impact in 2020, according to American Pistachio Growers.

Brown's team is part of a wider effort at UC Davis to support the sector's growth and adaptation to climate change. Other department members participating in the project include co-directors Louise Ferguson, a UC Cooperative Extension pomologist, and Richard W. Michelmore, a distinguished professor and director of the UC Davis Genome Center. Also participating are Giulia Marino, a UC Cooperative Extension specialist; and Grey Monroe, an assistant professor.

Other UC Davis participants include Trouillas and Brittney Goodrich, a UC Cooperative Extension specialist in the Department of Agricultural and Resource Economics. The project also includes researchers from UC Merced, New Mexico State University and Purdue University.

The four-year project was among nearly $70 million in Specialty Crop Research Initiative grants awarded this fall by the National Institute of Food and Agriculture. The Department of Plant Sciences landed three of the 25 grants.

Read the NIFA grant summary.

New interactive web tools help growers cope with climate change

UCCE, USDA California Climate Hub launch CalAgroClimate decision-support tool

Climate and weather variability pose increasing risks to farmers. As world leaders gather in Egypt at COP27 to address the climate crisis, University of California Cooperative Extension and the USDA California Climate Hub are launching new web-based tools to provide farmers with locally relevant and crop-specific information to make production decisions that reduce risk.

“Integrating historical weather data and forecast information with meaningful agricultural decision support information holds the potential to reduce a crop's vulnerability to such risks,” said Tapan Pathak, UC Cooperative Extension climate adaptation specialist at UC Merced.

“To provide easy access to high-resolution data in the form of agroclimate tools and information, and to enhance agricultural resilience to climate and weather-related risks, we are launching CalAgroClimate,” Pathak said.

Pathak is collaborating on building the decision support tool with partners from the U.S. Department of Agriculture, California Climate Hub, UC Cooperative Extension and UC Agriculture and Natural Resources' Informatics and Geographic Information Systems or IGIS.

“CalAgroClimate has been designed to support climate-enabled decision making for those working in the California specialty crop industry,” said Steven Ostoja, Director USDA California Climate Hub. “The USDA California Climate Hub is a proud collaborator on this important initiative to ensure the state's agricultural industry can continue to thrive in a future of climate change.” 

Shane Feirer and Robert Johnson of UC ANR IGIS designed the interactive tools on the website and Lauren Parker of the USDA California Climate Hub contributed to content organization.An advisory panel composed of colleagues from UCCE and the Natural Resources Conservation Service ensure CalAgroClimate tools are relevant to stakeholder needs.

“CalAgroClimate is an amazing new tool that puts comprehensive past and forecast weather data at any grower's disposal,” said Mark Battany, UC Cooperative Extension water management and biometeorology advisor for San Luis Obispo and Santa Barbara counties. 

“California's high-value crops are subject to a myriad of weather-related risk factors; this tool will allow growers to better address both near-term and long-term risks, and in the end grow more profitably, said Battany, who is a member of the CalAgroClimate advisory panel.

Growers and crop consultants can use CalAgroClimate's crop and location-specific tools and resources to help make on-farm decisions, such as preparing for frost or untimely rain and taking advantage of expected favorable conditions. 

CalAgroClimate currently includes heat advisory, frost advisory, crop phenology and pest advisory tools.

Heat advisory tool: Extreme heat poses a danger for people, animals and crops. With this tool, users can select location and temperature threshold (e.g. 90 F, 95 F 100 F) based on their crop-specific heat tolerance level and the tool will provide a customized map of heat risk for next seven days for that location, including the number of consecutive days with temperature above that threshold. Users can also assess overall heat risks across the state for a selected temperature threshold as well. Having an early warning about hot temperatures, growers can take steps to reduce risks associated with extreme heat such as providing shade, changing farm workers' schedules and applying additional irrigation.

Frost advisory tool: Frost risk is a very serious issue for many specialty crops across California. Similar to the heat advisory tool, this tool provides a customized map of frost advisory for next seven days for a user's location, and forecast of consecutive days with temperature falling below the selected temperature thresholds (e.g. 35 F, 32 F, 28 F). Similar to the heat advisory, early warning about cold temperatures can provide growers some time to protect their crops from frost damage. 

Crop phenology tool: The scientists have developed a-crop specific and location-specific crop phenology tool to help users keep track of growing degree days accumulations and estimate critical growth stages. CalAgroClimate uses a high-resolution PRISM dataset to provide near real-time crop phenology information to users. This tool will inform growers about how their crop development compares to previous years, which can be helpful in planning activities specific to critical growth stages.

Pest advisory tool: Similar to crops, development of certain pests and diseases is controlled by temperature and heat unit accumulations. With the pest advisory tool, growers can keep track of estimated pest generations during the growing season to make pest management decisions.

“We are launching the website with this initial set of tools while working on adding more crop-specific information and several new tools in the near future, ” Pathak said. “We look forward to getting feedback from growers who use CalAgroClimate to make it even more useful.”

 

New strategies to save the world’s most indispensable grain

Genetic insights help rice survive drought and flood

Plants — they're just like us, with unique techniques for handling stress. To save one of the most important crops on Earth from extreme climate swings, scientists are mapping out plants' own stress-busting strategies.

A UC Riverside-led team has learned what happens to the roots of rice plants when they're confronted with two types of stressful scenarios: too much water, or too little. These observations form the basis of new protective strategies.

“This one crop is the major source of calories for upwards of 45 percent of humanity, but its harvests are in danger,” said Julia Bailey-Serres, UCR geneticist and study lead. “In the U.S., floods rival droughts in terms of damage to farmers' crops each year.”

While it is possible for rice to flourish in flooded soils, the plants yield less food or even die if the water is too deep for too long. This work simulated prolonged floods of five days or longer, in which plants were completely submerged. It also simulated drought conditions.

In particular, the researchers examined the roots' response to both types of conditions, because roots are the unseen first responders to flood and drought-related stress.

Their work is described in a new paper published in the journal Developmental Cell.

One key finding is about a cork-like substance, suberin, that's produced by rice roots in response to stress. It helps protect from floods as well as from drought.

“Suberin is a lipid molecule that helps any water drawn up by the roots make it to the shoots, and helps oxygen from shoots to reach roots,” Bailey-Serres said. “If we reinforce the plant's ability to create suberin, rice has better chances for survival in all kinds of weather.”

The researchers were able to identify a network of genes that control suberin production and can use this information for gene editing or selective breeding.

“Understanding suberin is particularly exciting because it is not susceptible to breakdown by soil microbes, so carbon that the plant puts into suberin molecules in the roots is trapped in the ground,” said Alex Borowsky, UCR computational biologist and study co-author.

“This means that increasing suberin could help combat climate change by removing and storing carbon from the atmosphere.”

The researchers also identified the genes controlling some of rice's other stress behaviors.

“One of our interesting findings is that when rice plants are submerged in water, the root cell growth cycle goes on pause, then switches back on shortly after the shoots have access to air,” Bailey-Serres said.

In the future, the research team plans to test how modifying these stress responses can make the plant more resilient to both wet and dry conditions.

“Now that we understand these responses, we have a roadmap to make targeted changes to the rice genome that will result in a more stress-tolerant plant,” Bailey-Serres said.

Though heavy rains and droughts are both increasing as threats, Bailey-Serres has hope that new genetic technology can increase its resilience before it's too late.

“With genome editing, the fact that we can make a tiny but targeted change and protect a plant from disease is amazing. Though our crops are threatened, new technologies give us reasons to hope,” Bailey-Serres said.

UC Davis to lead $15 million research into climate-change resistant wheat

The project will also train plant breeders for the future

Wheat products account for roughly 20% of what people eat every day around the globe. As climate changes, wheat crops must adapt to new weather patterns to keep up with demand.

The University of California, Davis, is leading a five-year, $15 million research project to accelerate wheat breeding to meet those new climate realities, as well as to train a new generation of plant breeders.

“Everything is less stable,” said Jorge Dubcovsky, a plant sciences distinguished professor who is leading the grant research. “Everything is changing so you need to be fast. You need to be able to adapt fast.”

The grant from the U.S. Department of Agriculture's National Institute of Food and Agriculture will create a coordinated consortium of 41 wheat breeders and researchers from 22 institutions in 20 states. Researchers from Mexico and the United Kingdom are also participating.

Breeding needs to speed up

“Breeding crops for the future will require new traits, breeding platforms built for quick transfer of traits to elite cultivars, coordination of breeding efforts in public and private domains, and training for current and future plant breeders and researchers,” NIFA said in an announcement about this grant and others related to breeding.

The program involves on-the-ground research, identifying molecular markers and data analysis from multiple institutions to determine genes that will help wheat crops mitigate the effects of climate change. Plant breeding will follow to prove out those findings.

Wheat is unlike other crops in that 60% of the plant varieties — generating about $4 billion in annual production — are developed by public breeding programs rather than private corporations. In many states, wheat growers tax themselves to support basic breeding efforts at public institutions like UC Davis.

Increased coordinated research

The NIFA grant money will lead to more coordinated, sophisticated research. “This grant allows us to do breeding at a level that a good, modern company would do,” Dubcovsky said. “This grant is essential to maintain modern and effective public breeding programs in the U.S.”

The consortium will bring together data and research from across institutions, allowing for more expansive analysis while reducing redundancies. “We can take advantage of the data from everybody,” he said. “By doing that we don't need to duplicate efforts.”

A team in Texas will analyze plant images taken from drones at each institution to extract information about plant growth, water use, nitrogen levels and other data. “Using technology, we can see beyond our human capabilities,” Dubcovsky said. “You can extract a huge amount of information from every plant variety.”

The data from those images will allow researchers to document the plants throughout the life cycle and determine which plants fare better under certain conditions. Genotyping will help researchers obtain information about the plant genome. The combination of these two types of data could speed up breeding cycles, helping wheat crops adapt to a changing environment.

“If we can breed fast, we can adapt to change,” Dubcovsky said. “We are trying to make sustainable improvements in time.”

Training the next generation

The project will also train a cohort of 20 plant Ph.D. students in active breeding programs where they will participate in fieldwork, collect data from drones and DNA samples, and learn to integrate that information to accelerate wheat breeding. The students will participate in online and face-to-face workshops, as well as educational events and national scientific conferences.

Colorado State University, Cornell University, Kansas State University, Michigan State University, Montana State University, Oklahoma State University, Purdue University, South Dakota State University, Texas A&M University, University of Idaho, University of Illinois, University of Minnesota, University of Nebraska, University of Wisconsin, Utah State University, Virginia Tech, Washington State University, and U.S. Department of Agriculture Agricultural Research Service branches in North Dakota, Washington, Kansas and North Carolina are also participating in the consortium.

Researchers pinpoint drought-resistant traits in grape rootstocks

Findings could help wine industry adapt to climate change

Scientists at UC Davis have identified new root traits that help grapevines resist drought. The findings, published in the journal Annals of Botany, could speed up the development of grape rootstocks that protect vines from dry conditions, helping the grape and wine industry adapt to climate change.

The research, led by Department of Viticulture and Enology Assistant Professor Megan Bartlett, comes as 80% of California is experiencing extreme drought.

Most grapevines are not rooted directly into the ground but are instead grafted onto a rootstock, which forms the underground part of the plant and supports growth above ground.

“Rootstocks are an important tool to manage water stress,” Bartlett said. “Our goal was to identify traits that make rootstocks drought tolerant, so that grape breeders can amplify these traits in new varieties.”

Root cell traits

The study focused on traits measuring drought responses in living root cells.

The research specifically identified capacitance – which measures how much roots shrink as they dehydrate – as an important trait for drought tolerance.

“The water that enters the roots has to cross through a band of living cells to reach the xylem – the network of pipes that carries water up to the leaves,” said Bartlett. Most research has focused on xylem traits, but the living cells are often the first to be damaged during drought.

Water stress can shrink, deform, or even kill the living cells, causing the roots to shrivel away from the soil and lose access to the remaining soil water. Vines are then unable to replace water lost to evaporation and are forced to close the stomata – the small pores on the leaves that take in carbon dioxide for photosynthesis – to prevent severe dehydration. But closing the stomata stops photosynthesis and starves the vine of the sugars it needs to grow and ripen fruit.

This study is the first to test whether traits measuring root shrinkage and cell collapse can capture differences in rootstock drought tolerance.

Cell traits and drought tolerance

The researchers grafted Chardonnay onto eight commercial rootstocks. Half of the vines experienced drought conditions and half were kept well-watered in a greenhouse experiment.

The study found the eight rootstocks were surprisingly diverse and varied widely in their traits. The rootstocks also appeared to acclimate to drought by changing their traits in that the droughted vines were less susceptible to shrinkage and cell collapse than the well-watered vines.

Among the traits, capacitance was especially important for drought tolerance. The rootstocks with a lower capacitance (less root shrinkage) were better able to maintain photosynthesis during drought than other rootstocks.

“This research gives us a new trait to target for breeding more drought tolerant rootstocks,” study co-author and Ph.D. student Gabriela Sinclair said.

The research was supported by the American Vineyard Foundation, UC Davis, and by donations to the department from the Rossi family. Researchers at the University of British Columbia and the USDA-ARS Crops Pathology and Genetics Research Unit also contributed to the study.

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