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.
“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.
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.
Two-spotted mites in strawberries continue to be one of the biggest problems every year.
“We see more of it coming from the nurseries, and this year is no exception,” explained David Peck, COO and Farmer of Manzanita Berry Farms in Santa Maria.
“What’s interesting to me is that in the years that we’ve been using persimilis predator mite, and that has been since the early ’80s, we don’t see the persimilis taking over two-spot populations as early in the season as we used to,” Peck continued. “Whether that’s weather-related, humidity-related, or if there’s a change in the genetics of the commercially available persimilis, I don’t know.”
Peck said growers need to be aware of another trouble mite, the Lewis mite. Lewis mites have been seen on strawberries and raspberries in the Ventura area for some time, but growers appear to be noticing increased infestations in the recent years. Some growers have also seen them in Santa Maria in recent years, but they have so far not been reported from the Watsonville area. Considering the recent trend, growers might keep them in mind while scouting for pests.
“They’re out there, some places greater than others. Persimilis don’t like to eat Lewis mite. They are susceptible to all the same miticides. However, if you are relying heavily, on biologicals, you got to know if you have Lewis mite,” Peck said.
“I add fallacis predatory mites early in the season as a preventative for Lewis mite. The fallacis will eat two-spot or Lewis mite equally well and have done a pretty good job of keeping that initial early-season population of both mite species under control,” he explained.
Peck said that if there are mites in the strawberry nurseries, and the nurseries do not want to spray miticides, he understands that due to the possible development of pesticide-resistant mites showing up with plants.
“That’s a valid reason not to spray miticides at the nursery level. But there’s good data that fallacis will exist in those Northern California strawberry nursery areas, and they’re actually less expensive to procure than persimilis, and they survive through a wider environmental range than persimilis. They can handle colder, dryer, and hotter,” Peck said.
Some of the best data on strawberries and raspberries come out of Oregon State. It shows numerical data on how to put out the predatory mites, including how few you can put out.
“Personally, I’d be willing to spend an extra 50 cents or a dollar a thousand if the nurseries would inoculate their fields with fallacis. You might get a few predators coming in with your plants,” he said.
There is additional research on fallacis versus another predatory mite known as andersoni. Data shows that andersoni may be stronger than fallacis, thus doing a better job at controlling two-spotted mites.
Peck said that he has used andersoni on a test basis.
“I did not have enough of the predator to thoroughly complete a test in our organic fields, but I’m thinking that I will use that species for early season mite control.”
George Soares, a partner in Kahn, Soares, and Conway, a law firm based in Sacramento, recently spoke about the issues surrounding cannabis. He is managing partner of the firm and represents several agricultural commodity and trade groups in Sacramento.
He spoke at the recent California Associations of Pest Control Advisors (CAPCA) annual meeting in Anaheim. He touched on the fact that the California Department of Pesticide Regulation (DPR) is not thinking of the public in their handling of crop protection materials on cannabis.
“The people of California have decided that cannabis can be consumed by the public,” Soares said. “The question is how to grow the cannabis under the regulation.
Currently, the chemicals and fertilizers used to grow the cannabis are all illegal.
“So far, the solution is that we make it legal by stretching the interpretation of the law,” he explained.
By law, pesticides have to be labeled for use, and eligible crops must be on the label.
“The pesticides being used are being interpreted in ways to make it legal to use on cannabis,” Soares said. “Think about the damage that is doing to the legal structure of what we all adhere to.”
“DPR would never let a pesticide be used off-label, but when it comes to cannabis, it looks like the government is willing to let it slide,” he said.
Some innovative pest and disease control products, such as heat application to kill insects, are making their way to the market, according to Caltec.
California Ag Today spoke with Rudy Monnich, president of Caltec Ag, about some of the new ways California farmers are fighting pests.
“We have a product which is the diatomaceous earth that controls vine mealybugs and ants and mites in orchards and vineyards,” Monnich said, adding, “There is nothing more damaging than vine mealybug. In fact, Monterey County is forming a committee to be zero tolerant just for that insect pressure.”
The product is silica dioxide and will scarify the body of insects, dehydrate them, and in result kill them off in three or four days, Monnich explained.
However, the product is not a chemical, but a mineral, which significantly diminishes resistance issues.
“You don’t have the resistant issues build up,” Monnich said. “It’s also controlling thrip and whitefly in tomatoes.”
Caltec introduced the product this past spring.
Heat application can also be used by growers to combat insect problems.
“We are working with the Agrothermal people who have a machine that 300-degree to 400-degree temperatures will annihilate soft-bodied insects in tomatoes and powdery mildew in grapes,” Monnich said.
The application of heat kills the spores before signs of damage appear on the plant, Monnich explained.
This method of pest control is increasing the quality of wine, Monnich concluded.
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.
Big problems are arising in the cannabis growing areas of California.
John Fournier runs Acadia Regulatory Consulting in New York State. He on an EPA list of registration consultants. And because his company is high on the alphabetical list, he gets calls from cannabis growers in California who are looking for help in dealing with pests and diseases on their crops. Because cannabis production is federally illegal and the registered crop protection material products fall under federal guidelines, there are essentially few materials that growers can use.
“The biggest pressures for cannabis growers are powdery mildew, fungus gnats, and mites. If a grower had a bad spider mite outbreak, they would want to protect a super valuable investment. The question is, what are they willing to do to protect that investment? And in a situation like that, maybe you’ll go buy a miticide off the shelf somewhere,” Fournier said.
“As long as it’s not restricted use, anyone can buy it and use it on your crop. In that situation, that’s going to be a product that’s not approved for cannabis use on the state approved lists, difficult to control legally. There are also fungus gnats, which are a problem with plants that are overwatered.”
A lot of growing happens underground, and growers will have a soil mixture that is overwatered, which is one of the most common problems in cannabis.
“When the soil is overwatered, algae will start growing in the soil, and fungus gnats will find the crop and start feeding on the algae,” Fournier explained. “And then they’ll start feeding on the fine root hairs of the crop itself so they can actually kill the crop, if the outbreak is bad enough. Fungus gnats can be controlled by either an insecticide to kill the gnats, or you can use a biocide to kill the algae. Again, the materials must be registered for cannabis.”
According to Les Wright, Fresno County Agricultural Commissioner, illegal cannabis farms have been raided and officials have found empty containers of rodenticides, nematicides, insecticides, and miticides, all illegal for use on cannabis. “We always find illegal crop protection materials and many of them had labels in Spanish, most likely from Mexican syndicates.
Again, there are no conventional materials registered.
Now here’s the part where it gets dangerous. According to Fournier, “In states where recreational cannabis has been legalized, I have spoken to people who have said they’ve discovered through some means or another … dangerous levels of pesticide residues on cannabis, where a grower had obviously used hundreds of times more than the labeled rate of an insecticide to save their crop, and obviously this could be dangerous to consumers.”
By Colby Tibbet, California Ag Today Reporter
At the 40th Annual Meeting of the California Association of Pest Control Advisors (CAPCA) in Anaheim this week, Jeff Rasmussen, a pest control advisor with Crop Production Services in Kern County was recognized as the CAPCA Member of the Year.
“I’m humbled, it’s an awesome feeling to be presented with an award by your peers, and they appreciate all the efforts that we as a team have accomplished,” said Rasmussen.
Rasmussen is among a small group of PCAs who spearheaded the important Spray Safe program, which was created in Kern County in 2006 by a group of Kern County farmers and PCAs. Spray Safe was designed to reduce spray drift, enhance worker safety, and protect public health through more effective communications among farmers about pending and ongoing pesticide applications.
Rasmussen and the others dedicated time to solve a problem, “and since then we have stuck together and resolved the problem of spray drift. Proactive involvement can make a difference.”
“It’s the ‘Three C’s’: collaborate, connect, and commit, that has been our focus point. It’s a matter of the industry stepping up and taking responsibility, and continuing to own and protect that space,” said Rasmussen.
Ultimately, according to the Spray Safe website, the goal of the program is to instill increased resolve among farmers to take every precaution necessary to ensure public safety – this is particularly so when it comes to protecting farm workers and field crews.
At the heart of Spray Safe is a checklist.
The photo shows Jess Rasmussen, left, and his family at the Disneyland Hotel in Anaheim, following his honor.
Homeowners Urged To Make Sure Gardeners Who Apply Pesticides Have License
The California Department of Pesticide Regulation (DPR) is urging all homeowners to check that their maintenance gardener (landscaper) has a state maintenance gardening (MG) pest control business license from DPR if they are occasionally applying pesticides on their lawns. Homeowners can do so on the DPR website’s License and Certificate Holder List Page.
“Homeowners may not realize that maintenance gardeners are applying chemistry to their lawns,” says DPR director Brian Leahy. “We want to try and ensure they are doing so in a responsible manner.”
The license ensures that the person applying pesticides has been properly trained to use them on lawns and garden areas. If used properly, pesticides should not cause harm to humans or pets. However, improper use may result in illnesses or environmental problems.
Pesticides used on lawns and gardens may be washed to street storm drains and into local rivers, streams and even sensitive wetlands miles away. This may impact aquatic life.
“Your lawn may only be a small piece of land, but collectively, California lawns amount to many acres,” said Leahy. “Homeowners can play a significant role to reduce the amount of pesticide pollution (runoff) from lawns that are entering our waters through storm drains.”
Under California law, anyone who applies pesticides, even if it is only incidental to other maintenance gardening tasks, must have this DPR maintenance gardening pest control business license and be registered with the local county agricultural commissioner’s office.
In California, there are about 100,800 landscapers employed in the public and private sector who are responsible for maintaining homes, parks, golf courses, schools and plantings around malls, offices, restaurants and other locations.
Learn more about how your landscapers can obtain a certificate/ license at http://www.cdpr.ca.gov/docs/license/maintgardeners.htm
Terry Stark, President and CEO of California Association of Pest Control Advisors (CAPCA,) told 140 attendees at the Biopesticide Industry Alliance semi-annual early April meeting in Sacramento, what his organization thinks about the softer pest and disease control products.
“CAPCA represents 3,000 members of the 4,000 licensed-PCAs in California.
We have expanded our educational outreach through CAPCA-ED. We run 40 seminars annually throughout the state to aid all license-holders to improve their categories,” Stark announced,” said Stark.
“The regulatory burden pushes us to be better and more advanced,” Stark said. “CAPCA has 16 chapters, and each chapter has a director seated on the state board. My Chairman of the board is Jeremy Briscoe a Certis USA national manager. So I believe CAPCA is very well integrated with the biopesticide industry. Jeremy is the first representative that is a non-retail, non-independent to serve as the chair of CAPCA. This is a big move in the mentality of what we do,” said Stark.
CAPCA has traditionally centered on the San Joaquin Valley – production agriculture – the heart and soul of diversified agriculture and the money. “However, in the last 10 years, the wine industry has taken a step higher than the our other crops. All of a sudden we have Napa, Sonoma, Paso Robles, and southward to Santa Maria and Ventura County.”
Stark explained that everything west of I-5 tended to be the “softer side” of PCAs and chemical use in California. “I say that with respect because the wine industry was looking for ways to use less conventional products, ways to brand both organically and sustainability and with lower tolerances for their products. That caught on solidly seven or eight years ago.” Stark continued, “My largest independent PCAs are between Mendocino and San Francisco.”
“Like my Ventura guys and gals, they use more biological controls by releasing a lot of beneficials,” said Stark. “And it’s hard to come in with a hard-core application and maintain your beneficial populations,” he said.
When Stark was asked to speak at the Biopesticide Alliance meeting, he was asked to talk about perceptions. “I reflected on what I saw as a manager when they hired me to come to CAPCA. You talk about perception of biopesticides, with all due respect to my membership, 30 percent think that it’s one way or the highway.
In the central part of the state, from Kern County and throughout the desert valleys, it’s still spray and run. It’s big business, big acres. But it has its place,” said Stark.
He spoke about California being a hodgepodge of the most invasive species in the world, with many new pests coming in seemingly every week.
“Our entire citrus industry is facing Asian Citrus Psyllid which vectors the deadly citrus greening disease; we just survived the Glassy-winged sharpshooters in the wine industry; and, we’ve got Shot-hole bores coming to avocados. This represents huge production areas,” he said.
CAPCA has recognized that there are new ideas in pest and disease control and has moved towards being able to incorporate other chemistries, pheromones, and other items into the tool chest.
CAPCA’s Aging Demographics
Stark shared some demographics of CAPCA. “In CAPCA meetings, I don’t see a lot of dark-haired people sitting in the room. I don’t see a lot of females sitting in the room.
Our gender is 10-15 percent females,” he said.
Seventy five percent of my membership has 16-plus years of experience as PCAs. CAPCA also manages 1,000 Certified Crop Advisor (CCAs) who focus on nutrient recommendations, and the same demographics carry over to them. Of that, 35 percent have 30-plus years of experience. Do you think many will work past 30 years?
CAPCA’s last membership survey was done in 2010. We are projecting a 20% loss of membership by 2015. And that continues outward in a five-year cycle.
Through the Department of Pest Regulations we are only testing maybe 12-15 percent maximum replacements with young PCAs coming into the cycle.
How do we survive? We are turning to electronics, iPhones, and iPads.
PCAs have to be licensed in California if you are using restricted-use materials, soliciting for sale, and/or acting as an expert thereof. That takes care of the whole sales group too.
So, in biopesticides, you’re outside of that umbrella in most ways. You have some products that you to play with, but overall, that gives a “softer approach” for the younger PCAs to look at.
Sixteen percent of PCAs work in field and row crops; 34 percent in trees & vines, the only ones getting water this year; vegetables at 12 percent; and turf and ornamentals –10 percent. Turf and ornamentals in California drop 50 percent in the last 5 years with the collapse of the housing and commercial real estate industries, plus golf courses, they have had a pullback. So our members have moved to retail and other areas.
If you are in PAC and you are in retail, you represent 30 percent of the industry. Eighteen percent are independents, and that means you truly do your own thing: if you have alfalfa, you have 20,000 acres you’re looking at; if you have citrus, you’ve got 3-5,000 acres; if you have vineyards, you’d better have 2-3000 acres to pay for it—if you want to make big money—and you’re working 7 days a week to do that. Seventeen percent are in-house; these are the Paramount’s and the Boswells of the industry. They hire CCAs and PCAs like full-time employee of the ranch.
The dynamics of I-5 is not moving into the Central Valley or into the southern counties. You have pockets of Los Angeles and Santa Barbara where you have nursery stocks, that‘s always been kind of open to the biopesticides industry and its products.
What I think has made the biopesticide industry successful, beyond all of your research, hard work and marketing, are the opportunities and the new wave of using your thumbs, and twitter, and communications, and Facebook, and social media in general. The outreach that you can do your business on the iPhone and still drive down the road, answering your clients’ questions has enabled the “boutique” industry in the last 5 years to come closer to the mainstream because customers don’t have to do any special work to find out about you. You are in their feed lines of information. These are important tools,” said Stark.
“California is a highly-regulated environment, so electronics has complemented other resources. I think the known fact that many products are less toxic is a huge benefactor,” he said.
“Take the Light Brown Apple Moth, which ended up being a environmental community PR campaign that kicked food and agriculture’s butt in California. And now every fruit tree in Santa Cruz is going to die from the apple moth. You can’t even move the firewood because it will contaminate the rest of the area,” Stark said.
The unknown elements of a pheromone to treat the moth were a big problem because the public did not understand, and the industry took it for granted. “The pheromone is about as soft and appropriate as you can get in the marketplace,” said Stark. “But we need to approach the public in a different way. And I think the biopesticide industry is doing a much better job,” he said.
“I’d be remiss with all of the large companies sitting in the room, the BASF’s, Syngenta’s, Bayer’s, the Valent’s—all have learned to adopt and bring into their tool chest additional products that can complement their conventional materials and usually make the grower more profit,” noted Stark.
“CAPCA doesn’t get into this much, but we have a lot regulatory obligation responsibility to protect the field worker. The toxicity and the life of the product go a long way in how you get back into the field,” he said.
“So, in the biopesticide world, you have a better opportunity of targeting the exact pest you need to target. It’s not a broad-spectrum-type deal. So that gives you the advantage. My PCAs see that– my 50 percent younger side in the house – sees that. And that’s a positive for this industry,” Stark said.
IPM is not a word that is understood until you get to California. CAPCA cannot do anything in his recommendation without being CEQA-oriented (California Environmental Quality Act) must look for alternative uses before any restrictive material can be made; otherwise he is in violation of his own recommendation. IPM, and biopesticide products fit that requirement to make that check mark when they do that.
“In addition, biologicals are lower priced than they ware 7-8 years ago. And that’s good because the grower doesn’t spend a dime more than they have to. If you think PCAs are out there pounding product or fertilizer on, and the farmer is not making any money, just three minutes later in the coffee shop, that guy is fired and another is hired,” Stark said.
“It is important to the sustainability in going forward, when you have a regulatory environment like we do in California. We have a built-in arena here and people are always listening to what can be done better and still make a profit. In my opinion, you are off to the races and biopesticides are mainstream now,” noted Stark.
If you can hit 15-20% of the marketplace, it’s been a great quarter-century run for you to get there and I think the CAPCA membership is looking forward to a long-lasting relationship.
He reminded attendees of the popular CAPCA Conference, Oct. 19-21, 2014 at the Disneyland Hotel in Anaheim. “I have 1,300 attendees and 150 exhibitors. What better place to be than with 800-900 license holders. It’s all relationships. Once you get the relationship, your social media, and your electronics, your product will sell itself,” Stark concluded.