Pests and Diseases Cause Worldwide Damage to Crops

Pests and Pathogens Place Global Burden on Major Food Crops

By Pam Kan-Rice, UC Agriculture & Natural Resources

Scientists survey crop health experts in 67 countries and find large crop losses caused by pests and diseases

Farmers know they lose crops to pests and plant diseases, but scientists have found that on a global scale, pathogens and pests 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.

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

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”

The study estimates the 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. 

UC Agriculture and Natural Resources researchers and educators draw on local expertise to conduct agricultural, environmental, economic, youth development and nutrition research that helps California thrive. Learn more at ucanr.edu.

Boost Biomes Working on Disease Resistance

Researching the New Frontier

By Jessica Theisman, Associate Editor

California Ag Today recently spoke with Robert McBride of Boost Biomes. McBride explained his vision for the company.

“It’s the new frontier; It has not been researched that much,” he said.

He told us that the company is working on getting the correct microbes into the soil to enhance plants’ productivity.

“I would say the key thing that we think about in terms of getting the right microbes into the soil is that microbes are kind of like a plant’s second genome,” McBride said.

Genomes have the ability to impact the plant’s phenotype, along with the way the plants grow in different temperatures and soil salinity levels.

“They can change the flavor of the fruits and it is all controlled by the microbes in the rhizosphere,” McBride explained.

Boost Biomes is interested in controlling pest resistance. The microbiome shifts to a state that is protective.

“What we would like to do is take soils that are not protective and encourage that shift to happen more quickly,” McBride said.

Boost Biomes takes advantage of the natural microbes in the soil and rhizosphere that protect the plants.

“We are trying to identify the right network to put into the soil to get into the rhizosphere to make the plants resistant against diseases,” McBride explained.

A Brief History on the Pest Control Adviser and Certified Crop Adviser Programs

Longtime Crop Adviser Helped Increase Job Market for CCA Industry

By Brian German, Associate Broadcaster

 

The Certified Crop Adviser Program (CCA) was introduced in 1992 as a means to address the increased concerns regarding agriculture’s contributions to a variety of environmental issues.  By 1994, the CCA program was fully established with the support of the California Department of Food and Agriculture, along with the American Society of Agronomy and the California agricultural industry. The program was designed to raise the awareness and professional standards of individuals who make recommendations on agricultural fertilizers, pesticides and related products. 

Allan Romander has a long history with the CCA program, having joined the CCA Board in 2004. “I am currently with the Certified Crop Adviser Program in California, and Arizona I might add. I am a consultant with the organization. I just concluded my term as ICCA Chair and past Chair,” Romander said.

Allan Romander, member, California Certified Crop Adviser Board
Allan Romander, member, California Certified Crop Adviser Board

A Pest Control Adviser (PCA) since 1979, Romander joined the California CCA Board in 2004 and was instrumental in helping to develop a marketing program that nearly doubled the number of CCAs in California in a little less than six years. 

California is one of just a few states that require people who advise farmers on pest control management to be licensed as a Pest Control Adviser.  Amidst rising public concerns regarding pesticide use on California farms, the PCA program was launched in 1973 to ensure that those who make pesticide recommendations are both qualified and knowledgeable. “But that only certified them in the area of pest management,” Romander said. “It never said anything about their competency in the area of crop management or soil or water management.”

certified crop adviser logo“There has long been a gap between growers and consultants. Consultants historically have just held a Pest Control Adviser’s license,” Romander said. Over time, farmers began to ask their PCAs for guidance on multiple subjects outside of pest control, such as fertilizers and irrigation. 

“That’s where the Certified Crop Adviser Program comes in and picks up where the PCA program leaves off.  It covers those categories and certifies to a grower that [the adviser] has competency in those other areas,” Romander said.

Currently, there are close to 4,000 EPA-licensed Pest Control Advisers in California.  Romander noted, “Eighty-five percent of the Certified Crop Advisers in California are also Pest Control Advisers. So it’s a well-established program and well-respected throughout not only the United States, but North America and the rest of the world.”

USDA NRCS Works To Increase Diversity

NRCS Conducts Outreach for Diversity

 

By Emily McKay Johnson, Associate Editor

 

The United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) works with local growers across America to conserve the nation’s soil, water, air and other natural resources. Elisabeth “Elise” Miller, is an area engineer for the entire Southern California region. “I also serve my agency as the NRCS-California LGBT Special Emphasis Program Manager, a collateral duty that I perform on several levels to increase diversity,” said Miller.

 

“First, I work to educate employees within my agency, to make them better informed and more in tune to language,” Miller explained. “Then, I work to get a more diversified workforce within the USDA,” she added, to make the organization stronger and better.

 

Unlock the secrets in the soil diversity

“My efforts might include going to a university,” she elaborated, “trying to tie in with their resource center and encouraging more people who identify as LGBT to apply for federal jobs. Our colleges, the University of California (UC) and the California State (Cal State) University system, have a lot of really good, positive and powerful resource centers that I’m hoping will continue to help us with our outreach and pull more people in who want to work for us.”

 

“Certainly we do have human resources,” commented Miller. “And we do a lot of outreach. With California being so large and so diverse,” Miller said, “it is hard to reach out to everybody. We have to start with the big UC schools first. We also try to reach out to universities such as Fresno State, Cal Poly, San Luis Obispo or Pomona or UC Davis, or Humboldt State. Those would be schools that certainly we want to outreach to and try to bring more of those graduating students in under our fold.”

 

“My agency is a very technical agency,” said Miller. “We work on conservation-type issues—resource issues that farmers, ranchers or private landowners might deal with—requiring an agronomist, biologist or soil scientist. I often go out with a multi-disciplinary team and meet with a farmer, rancher, or just a landowner.”

 

“Every farmer I meet has some kind of issue,” Miller commented, “whether it’s pest management, whether it’s dealing with manure management or an erosion issue that’s going on. If they have a hillside orchard, they have to deal with that.”

 

“And obviously they focus a lot on drought management and water conservation,” Miller explained, “A lot of these farmers of course are forced to use groundwater, which is depleting the groundwater sources and may be causing irreparable damage.

 

We work cooperatively to try to help them resolve their land issues. That’s what I like about my agency—that we’re invited there. We’re not there to push a regulation. We’re there to help them to better manage. They always maintain control of their decision making. We try to give them options available and we have cost share programs to assist them, if something is identified. We work towards developing conservation plans on the property.”

 

The agency is also responsible for the soil survey work. “We map the soils five feet deep,” said Miller, “to gather information, resource information, which has worked fantastically well for a farmer to know what kind of soil he’s dealing with. It may make a difference on how a farmer irrigates. It may be why he’s having a problem with a crop or many other areas that could be helpful to them.”

 

“We are in the community. We’re very much aware; we know who the farmers are, we know what the issues are and we work with farmers to try to address their land problems. We don’t just pop in and then pop out,” Miller said.


The United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRSC) works with local growers across America to conserve the nation’s soil, water, air and other natural resources with voluntary programs and science-based solutions that benefit both the landowner and the environment. 

New IPM Work on Brown Stink Bug

New IPM Approach to Brown Stink Bug In Desert Cotton

By Patrick Cavanaugh, Farm News Director

This year, the UC Division of Agriculture and Natural Resources, Cooperative Extension, Riverside County began an Integrated Pest Management (IPM) program to control Euschistus servus, or brown stink bug, a problem in Southern California’s cotton production areas.

Vonny Barlow
Vonny Barlow, a UC Cooperative Extension farm advisor in Riverside County

Vonny Barlow, a UC Cooperative Extension farm advisor in Riverside County began evaluating brown stink bug in cotton last year, and he received additional funding this year from a National Institute of Food and Agriculture (NIFA) grant administered through North Carolina State University, to continue his research this year. Barlow just hired two interns to work with brown stink bug in the Palo Verde Valley in Southern California.

The pest was known to exist in Arizona for about eleven years, but was not a critical issue until about three years ago, when it moved into California. California cotton growers had to spend a lot of money to spray to manage the insect, and it just wasn’t economically feasible.

“In many areas in the south, the brown stink bug pierces into the cotton boll with its proboscis-like mouthpart—a stiff, short straw,” said Barlow. “Once the cotton boll is pierced, the brown stink bug tries to feed on the cotton seed. The problem is the puncture allows bacteria to enter and boll rot to set in. Boll rot is the issue because it lowers yield quality; without boll rot, the brown stink bug is much more of a manageable pest.”

Spraying is not the answer to control the bug, according to Barlow. “We are going to look at an area-wide pest management approach by just essentially surveying the pest control advisers (PCAs) and growers about cropping that is near or even some miles away from cotton,” he said. “Where is the brown stink bug showing up? When did it show up? Is it moving? When are you going to harvest? Is it moving into the cotton? That way, we can give the cotton growers a better idea of when they should start management practices for brown stink bug, instead of just routinely calendar-spraying every two weeks.”

“We hope to predict when brown stink bug will move into cotton. Farmers who just harvested wheat should expect it will come into your field within the week. Start scouting; it is another very good IPM tactic to reduce sprays and to better manage pests,” said Barlow.

Featured image: Brown Stink Bug (Source: Brown Stink Bug (Source: “Chemical Efficacy Trial using Select Insecticides against Brown stink bug, Euschistus servus on Commercially Planted Cotton” by Vonny Barlow, University of California, Agricultural and Natural Resources, Riverside County, April 2016 issue of “Postings from the Palo Verde” newsletter)

Bayer CropScience’s New West Sacramento Facility to Focus on Biopesticides

Biopesticides Are Valuable Part of Pest and Disease Control


By Colby Tibbett

Bill Stoneman is the executive director of the Biopesticide Industry Alliance, which is dedicated to fostering adoption of biopesticide technologies through increased awareness about their effectiveness and full range of benefits to a progressive pest management program.

“These are very important tools in terms of resistance management because they allow us to target alternative modes of action against pests. Biopesticide technologies are tools in the quiver, as well as the chemistries we are currently using and developing,” said Stoneman.

Biopesticides offer many other benefits, such as no maximum residue level (MRL) issues, reduced preharvest intervals and decreased reentry intervals.

Bill Stoneman, Biopesticide Industry Alliance Executive Director
Bill Stoneman, Biopesticide Industry Alliance Executive Director

“What you’re going to find, is that they will be used in rotation with the chemical pesticides or other cultural methods to prevent plant diseases and insects. I think you’re going to see more development in the seed treatment area. Again, seed is a good delivery mode to get things to the plant’s roots, and that’s where a lot of these materials are effective, from the plant-disease perspective,” said Stoneman.

With regard to insect control, Stoneman said, “We’re going to see new things coming into the marketplace. Some insect-specific viruses are going to be expanding in the U.S. soon, with applications on a variety of crops—but very insect specific—so in other woBill Stoneman Bayer Crop Science West Sacramentords, they kill only that insect, so there is no harm to pollinators or beneficials,” said Stoneman.

This will be more common in the future, according to Stoneman, “I think we will see as a trend going forward more reliance on the biologicals, pollinators, tailored pest control programs and IPM approaches to preventing any damage to those natural control forces in agriculture,” said Stoneman.

A big step for Biopesticides in California was the recent grand opening of the Bayer CropScience’s $80 million investment in their biologics and seed business in West Sacramento. It will focus on this new frontier of pest and disease control.

 

Adrian Percy, Bayer CropScience Global Research and Development (Source: www.bayercropscience.com)
Adrian Percy, Bayer CropScience Global Research and Development (Source: www.bayercropscience.com)

Adrian Percy, global head of research & development (R&D) with Bayer CropScience, explained Bayer’s decision for the West Sacramento location, “First and foremost, California is an amazing hub of agricultural innovation. We have UC Davis just down the road, which we have close ties to. In 2012, we purchased AgraQuest, which was based in Davis, so basically we’re moving them into this new facility which is much bigger and more state-of-the-art than what they were using previously,” said Percy.

“We’re really excited because here we will be researching brand-new applications based on bacterial-based products, fungicides, insecticides, etc. In addition, we will be developing new vegetable seed varieties,” said Percy.

Among the advantages of these new biologic tools for growers is avoidance of MRLs, a big boon for vegetable growers. “We see a lot of advantages for these types of products. And this is one of the fastest growing sectors both for us as a company, but also in general. What we are seeking to do now is bring next generation products to the marketplace which are even better than the ones we have today,” said Percy.

“These kinds of products, I think from a stewardship and management perspective, are very advantageous to the grower,” he added.