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Pests and pathogens place global burden on major food crops

On a global scale, pests and pathogens are significantly reducing yields of rice (shown), wheat, maize, soybeans and potatoes.

Farmers know they lose crops to pests and plant diseases, but scientists have found that on a global scale they are reducing crop yields for five major food crops by 10 percent to 40 percent, according to a report by a UC Agriculture and Natural Resources scientist and other members of the International Society for Plant Pathology. Wheat, rice, maize, soybean and potato yields are reduced by pathogens and animal pests, including insects, scientists found in a global survey of crop health experts.

At a global scale, pathogens and pests are causing wheat losses of 10 percent to 28 percent, rice losses of 25 percent to 41 percent, maize losses of 20 percent to 41 percent, potato losses of 8 percent to 21 percent, and soybean losses of 11 percent to 32 percent, according to the study, published in the journal Nature, Ecology & Evolution.

Sheath blight on rice
Viruses and viroids, bacteria, fungi and oomycetes, nematodes, arthropods, molluscs, vertebrates and parasitic plants are among the factors working against farmers.

Food loss

“We are losing a significant amount of food on a global scale to pests and diseases at a time when we must increase food production to feed a growing population,” said co-author Neil McRoberts, co-leader of UC ANR's Sustainable Food Systems Strategic Initiative and Agricultural Experiment Station researcher and professor in the Department of Plant Pathology at UC Davis.

While plant diseases and pests are widely considered an important cause of crop losses, and sometimes a threat to the food supply, precise figures on these crop losses are difficult to produce.

“One reason is because pathogens and pests have co-evolved with crops over millennia in the human-made agricultural systems,” write the authors on the study's website globalcrophealth.org.  “As a result, their effects in agriculture are very hard to disentangle from the complex web of interactions within cropping systems. Also, the sheer number and diversity of plant diseases and pests makes quantification of losses on an individual pathogen or pest basis, for each of the many cultivated crops, a daunting task.”

“We conducted a global survey of crop protection experts on the impacts of pests and plant diseases on the yields of five of the world's most important carbohydrate staple crops and are reporting the results,” McRoberts said. “This is a major achievement and a real step forward in being able to accurately assess the impact of pests and plant diseases on crop production.”

The researchers surveyed several thousand crop health experts on five major food crops – wheat, rice, maize, soybean and potato – in 67 countries.

“We chose these five crops since together they provide about 50 percent of the global human calorie intake,” the authors wrote on the website. The 67 countries grow 84 percent of the global production of wheat, rice, maize, soybean and potato.

Top pests and diseases

 

Late blight in a potato field.

The study identified 137 individual pathogens and pests that attack the crops, with very large variation in the amount of crop loss they caused. For wheat, leaf rust, Fusarium head blight/scab, tritici blotch, stripe rust, spot blotch, tan spot, aphids and powdery mildew caused losses higher than 1 percent globally. In rice, sheath blight, stem borers, blast, brown spot, bacterial blight, leaf folder and brown plant hopper did the most damage. In maize, Fusarium and Gibberella stalk rots, fall armyworm, northern leaf blight, Fusarium and Gibberella ear rots, anthracnose stalk rot and southern rust caused the most loss globally. In potatoes, late blight, brown rot, early blight and cyst nematode did the most harm. In soybeans, cyst nematode, white mold, soybean rust, Cercospora leaf blight, brown spot, charcoal rot and root knot nematodes caused global losses higher than 1 percent.

Food-security “hotspots”

Stripe rust in wheat
The study estimates to losses to individual plant diseases and pests for these crops globally, as well as in several global food-security “hotspots.” These hotspots are critical sources in the global food system: Northwest Europe, the plains of the U.S. Midwest and Southern Canada, Southern Brazil and Argentina, the Indo-Gangetic Plains of South Asia, the plains of China, Southeast Asia, and sub-Saharan Africa.

“Our results highlight differences in impacts among crop pathogens and pests and among food security hotspots,” McRoberts said. “But we also show that the highest losses appear associated with food-deficit regions with fast-growing populations, and frequently with emerging or re-emerging pests and diseases.”

“For chronic pathogens and pests, we need to redouble our efforts to deliver more efficient and sustainable management tools, such as resistant varieties,” McRoberts said. For emerging or re-emerging pathogens and pests, urgent action is needed to contain them and generate longer term solutions.”

The website globalcrophealth.org features maps showing how many people responded to the survey across different regions of the world. 

In addition to McRoberts, the research team included lead author Serge Savary, chair of the ISPP Committee on Crop Loss, epidemiologists Paul Esker at Pennsylvania State University and Sarah Pethybridge at Cornell University, Laetitia Willocquet at the French National Institute for Agricultural Research in Toulouse, France, and Andy Nelson at the University of Twente in The Netherlands. 

 

Posted on Friday, February 8, 2019 at 11:11 AM
Focus Area Tags: Agriculture Food

Antoine Brieux to Share PPTM Research on Fruit Fly

Postdoctoral fellow Antoine Brieux of the Joanna Chiu lab, UC Davis Department of Entomology and Nematology, will present a seminar at 4:10 p.m., Wednesday,  Feb. 13 in Briggs Hall on

Postdoctoral scientist Antoine Brieux of the Joanna Chiu lab, UC Davis Department of Entomology and Nematology, is gearing up for a seminar next week on his research on the fruit fly, Drosophila melanogaster, involving photoperiodic time measurement...

Postdoctoral fellow Antoine Brieux of the Joanna Chiu lab, UC Davis Department of Entomology and Nematology, will present a seminar at 4:10 p.m., Wednesday,  Feb. 13 in Briggs Hall on
Postdoctoral fellow Antoine Brieux of the Joanna Chiu lab, UC Davis Department of Entomology and Nematology, will present a seminar at 4:10 p.m., Wednesday, Feb. 13 in Briggs Hall on "Understanding the Molecular Mechanisms Underlying Photoperiodic Time Measurement in Drosophila melanogaster."

Postdoctoral fellow Antoine Brieux of the Joanna Chiu lab, UC Davis Department of Entomology and Nematology, will present a seminar at 4:10 p.m., Wednesday, Feb. 13 in Briggs Hall on "Understanding the Molecular Mechanisms Underlying Photoperiodic Time Measurement in Drosophila melanogaster."

California's four seasons are fire, flood, mud and drought

Farmers and ranchers are typically the first to feel droughts, a condition that seems to be impacting California on an increasing basis, reported Dustin Klemann on KSBY News on California's Central Coast.

Klemann joined a UC Cooperative Extension drought meeting in Solvang titled “Weather, Grass, and Drought: Planning for Uncertainty.” Ironically, the meeting came at a time when California has been blessed by a series of wet and snowy storms.

“Leave it to a drought workshop to bring the rain,” said UCCE livestock and natural resources advisor Matthew Shapero.

Despite the rain, the National Drought Monitor still considers the Central Coast area to be in "moderate drought."

Shapero told about a local rancher who recently called him to question the status. 

“He said ‘I really don't think the drought monitor accurately reflects what I am seeing on the ground.'”

California's drought status is challenging to pin down because of vast precipitation variability. For example, Paso Robles received 2.78 inches of rain all of 2013. In 1941, the town recorded almost 30 inches of precipitation.

UCCE natural resources and watershed advisor Royce Larsen also spoke at he meeting.

“We Californians are constantly accused of not having seasons. We do,” Larsen said. “We have fire, flood, mud, and drought. That's what we live with. And it's getting more and more so every year.”

California's four seasons are fire, flood, mud and drought.
Posted on Thursday, February 7, 2019 at 2:22 PM
Focus Area Tags: Agriculture Environment

4-H member is a winner from curly haired cavies to chocoflan

Celeste Harrison with her prize-winning chocoflan dessert. (Photo by Kathy Keatley Garvey)
From cavies to chili to chocoflan...

Thirteen-year-old Celeste Harrison, a fourth-year member of the Sherwood Forest 4-H Club, Vallejo, shares her expertise about chili and cavies (guinea pigs), but she's also a pro in the kitchen and at making a dessert called “Chocoflan.”

It's part cake, part flan.

The chocolate dessert recipe originates “from my Great-Aunt Esther and it's what we serve at all our family gatherings,” she said.

It's a winning one, at that. And just in time for Valentine's Day.

Celeste baked the dessert for the recent Solano County 4-H Project Skills Day — where 4-H'ers share what they're learned in their projects — and her presentation and recipe earned a showmanship award, one of seven awarded.

Last year she won a showmanship pin for her project, “Curls Just Want to Have Fun: How to Care for Your Curly Haired Guinea Pig.”

Celeste, a seventh-grader is active in 4-H. She serves as the treasurer of her 4-H club and last year served as a Science, Engineering and Technology (SET) officer in the Solano County 4-H Program. This year she's enrolled in five projects: cavies, poultry, dogs, record keeping and rabbits.

Always eager to learn, Celeste decided to “take dogs, rabbits and poultry so I can learn showmanship,” she said, noting that she competed in the Round Robin Small Animal Showmanship at two county fairs last year but was inexperienced at showing animals other than cavies. So this year's she's set her sights on learning more about them. Her goal: to place first in Round Robin.

No stranger to the kitchen, Celeste served as a member of the Sherwood Forest 4-H Club's Chili Cook-Off team for the last two years in the Solano County 4-H Project Skills Day.

This year, however, she turned from chili to chocoflan. The evaluators loved it! So did the 4-H'ers and their families who sampled it.

Here's the recipe:

Chocoflan Recipe

A bundt pan, deep roasting pan, blender, large bowl and a hand mixer are needed for this recipe.

Ingredients for flan:
A 14-ounce can of sweetened condensed milk
A 7.6-ounce can of Media Crema (light cream)
2 teaspoons vanilla extract
8 ounces of cream cheese
5 eggs

Ingredients for chocolate cake:
2 cups white sugar
1-3/4 cups all-purpose flour
3/4 cup unsweetened cocoa powder
1-1/2 teaspoons baking powder
1-1/2 teaspoons baking soda
1 teaspoon of salt
2 eggs
1 cup milk
1/2 cup vegetable oil
3/4 cup sour cream
2 teaspoons vanilla extract
1/2 cup hot water

Directions:
Put an oven rack in the middle of the oven and preheat to 350 degrees. Coat a bundt pan with cooking oil spray.

Sift flour, salt, baking powder and baking soda in a large bowl. In a separate bowl, combine eggs, milk, vegetable oil, vanilla and cocoa mixture and beat with a hand mixer for two minutes. Add the wet mixture in increments of one cup into flour mixture until thoroughly combined. Stir cocoa powder into hot water until melted and then stir into cake mix and set aside.

In a blender, add in all flan ingredients and blend on high until smooth. Pour cake batter into a bundt pan (make sure surface is level). Pour flan mixture into the cake batter but do not mix (it will sink to the bottom of the bundt pan while in the oven).

Put chocoflan into a large roasting pan and fill the pan with about 2 inches of warm water. Spray a piece of aluminum foil with cooking spray and set it on top of the bundt pan (but do not fold it over the bundt pan.) Bake for one hour and 45 minutes. Remove cake from oven and let cool before inverting it onto a serving platter. Enjoy.

Solano County 4-H Program
The Solano County 4-H Youth Development Program, part of the UC Cooperative Extension Program, follows the motto, “Making the Best Better.” 4-H, which stands for head, heart, health and hands, is open to youths ages 5 to 19.  In age-appropriate projects, they learn skills through hands-on learning in projects ranging from arts and crafts, computers and leadership to dog care, poultry, rabbits and woodworking. They develop skills they would otherwise not attain at home or in public or private schools. For more information about Solano County 4-H, contact 4-H program representative Valerie Williams at vawilliams@ucanr.edu.

 

Celeste Harrison's chocoflan dessert was a big hit at the Solano County 4-H Project Skills Day. She won a showmanship award. (Photo by Kathy Keatley Garvey)

Celeste Harrison served as a member of the Sherwood Forest 4-H Club’s Chili Team for two years. Members of the 2018 team that prepared Ruby Redstone Chili were (from left) Darren Stephens, Celeste Harrison, Julietta Wynholds and Hanna Stephens. (Photo by Kathy Keatley Garvey)
From cavies to chocoflan: At the 2018 Solano County 4-H Project Skills Day, Celeste Harrison won a showmanship award for her cavies (guinea pig) project: "Curls Just Want to Have Fun: How to Care for Your Curly Haired Guinea Pig.” Here she explains her project to evaluator Sharon Taylor of Dixon. This year she focused on chocoflan and won another showmanship pin. (Photo by Kathy Keatley Garvey)

Posted on Thursday, February 7, 2019 at 2:11 PM
Focus Area Tags: 4-H Food

New project to build climate resilience through improved land management

ANR is partnering with UC Merced and UC Irvine scientists to develop new tools and methods for better land management.

A $4.6 million grant to UC Merced and UC Irvine will help UC Agriculture and Natural Resources researchers develop new tools and methods for California land owners to better manage the state's forests, shrub lands and grasslands.

California's Strategic Growth Council agreed to fund the Innovation Center for Advancing Ecosystem Climate Solutions, a three-year program co-led by UC Merced Professor Roger Bales and UC Irvine Professor Michael Goulden. The money comes through California Climate Investments, a statewide initiative that puts billions of cap-and-trade dollars to work

The goals include reducing wildfire risk, improving long-term carbon sequestration and bolstering resilience in the face of climate change, with an emphasis on California's rural regions and low-income communities.

“Our part of the project is to work with stakeholders and identify areas where we can focus management practices to promote healthy forests, minimize wildfires, improve water security and increase carbon sequestration,” said Toby O'Geen, UC Cooperative Extension soil resource specialist at UC Davis.

“Right now, many of California's forests, shrub lands and grasslands are carbon sources, and we need to change them into carbon sinks,” said Bales, director of the Sierra Nevada Research Institute and distinguished professor of engineering. “Our research will address information bottlenecks to guide decision making, build local capacity for science-based land management and develop methods for translating benefits of land restoration into financing for land restoration.”

California's recent drought, tree die-offs, wildfires and rising temperatures all point to the necessity of improved forest stewardship, Goulden said.

“Officials in the state government and agencies recognize this need, but uncertainty over how to proceed has sometimes slowed progress,” he said.

Most of the work will be conducted by scientists at Merced and Irvine, but collaborators from UC Berkeley, UC Davis, Stanford University, San Diego State University and the University of California Division of Agricultural and Natural Resources, as well as state agencies, will play important roles.

“This research will enable UC Cooperative Extension advisors to provide better advice to land managers to reduce the severity of wildfires,” said Glenda Humiston, UC vice president for agriculture and natural resources. “Severe wildfires are not only releasing greenhouse gases, but polluting the air of many communities, aggravating the health of people in less-affluent, inland areas such as Tulare, Yuba and Mariposa counties.”

At UC Merced, an interdisciplinary group of researchers from two departments — Civil & Environmental Engineering and Management of Complex Systems — will collaborate with UC Cooperative Extension and engage with local stakeholders. The group will study and identify the most-effective land-management practices, in terms of water conservation, forest health, fire resistance and carbon capture.

“We will develop the spatial data and analysis tools to plan landscape restoration, develop local capacity for better managing the state's wildlands in a warming climate, and enumerate the greenhouse gas and other benefits from investments in land management,” Bales said.

Goulden, professor of Earth systems science, said UC Irvine researchers will use a big-data approach to analyze observations collected by satellites since the 1980s to measure the efficacy of thousands of past and ongoing forest treatments, while UC Merced takes a different approach.

“We will work with groups in rural communities to systematically evaluate how well, or poorly, our products can support decision making,” Bales said, “and then develop both implementation pathways and policy recommendations to better and more-quickly implement landscape-restoration and carbon-capture projects across the state.”

Because there are critical gaps in the understanding of carbon cycles, uptake by forests and negative feedback from climate change, this project initiative has been established to develop new knowledge through measurements and modeling. Researchers will synthesize the resulting data to produce actionable information for stakeholders.

Bales and Goulden agreed the Innovation Center will target low-risk, high-yield opportunities to reduce California's greenhouse-gas contributions.

Just a small improvement in management efficiency will have meaningful benefits — on the order of several million metric tons of CO2 per year, Goulden said.

The program will also benefit low-income communities in the state by reducing wildfire risk, which disproportionately impacts poorer areas in California by maintaining water quality through better vegetation management; by fostering tourism in disadvantaged locales; and by preparing students in these areas for careers in sustainability and climate resilience.

Posted on Thursday, February 7, 2019 at 11:57 AM
Focus Area Tags: Environment Natural Resources

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