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Posts Tagged: Pest Management/Diseases

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

Living with Wildlife – Outcomes and actions following the recent workshop at UC ANR Hopland REC

submitted by Hopland REC Director, Dr. Kim Rodrigues

Since arriving as the Director for HREC in 2013-2014, I have been committed to protecting all of the amazing resources here at the Hopland Research and Extension Center (HREC,) with a dedicated effort to saving wildlife and reducing losses of sheep.  As one of the last remaining sheep research facilities and one of the largest flocks in our immediate area, the sheep are prey to coyotes and other potential predators on the landscape. 

IMG 5223 (2)

With increasing numbers of wildlife across the region, state and nation, conflicts between humans and wildlife are increasing.  Our workshop at HREC on August 31, 2017 focused on living with wildlife while managing livestock, with an overarching goal to seek a shared understanding of non-lethal tools through research, implementation and education.

Over 80 participants from a diversity of backgrounds including researchers, ranchers, community members and non-profits attended. All participants experienced demonstrations of several non-lethal tools, including some exciting applications of scary devices, such as Halloween decorations, collars to protect sheep with strobe lights and canine avoidance noises built into them, fencing with an electric charge, lion proof pens and flagging attached to deter movement across the fencing and more.  Many participants wanted more hands-on field time with the ranchers using these tools and HREC is working to develop this for late spring/early summer of 2018.

We explored new and emerging research with Dr. Brashares and his team only to learn that it “depends.”  Everything is situational and place-based and this is a key lesson or outcome from the meeting.  The situational questions asked of each rancher on the panel may help inform the choice of tools and the mix of tools to reduce losses.

IMG 5219 (2)

We learned that there are practical barriers – such as time, money and labor, as well as scientific barriers to fully implementing non-lethal tools.  Yet, one common message was to mix and match tools and vary them frequently.  “Match” the tools to your specific situation(s) and mix them up over time and space frequently.   Many creative ideas came up to help share tools and other resources and the concept of a lending library with non-lethal tools available to ranchers emerged as a local action HREC will explore further with our community partners.

We understand the importance of strong working relationships and diverse partnerships and we will work with the participants who were able to attend and outreach to partners, such as local agricultural commissioner and staff, California Department of Fish and Wildlife and Wildlife Services to ensure we are all working together. 

We learned from and valued the diverse perspectives and there was a tremendous sense of respect for all people present that allowed a dynamic and safe learning environment.

Already, HREC is moving forward with new research to better track and document the work of our large guard dogs (LGDs) as a tool to prevent losses of livestock. The concept of putting GPS collars on our dogs and tracking their movements over a variety of pasture types and sizes and landscapes is already being discussed and outlined by HREC staff and research colleagues. It is recognized that LGDs can and do kill wildlife, so they are not truly a “non-lethal” tool yet they remain one of the most important tools livestock managers rely on to protect their animals.  Lethal controls are still used in combination with non-lethal tools – snares, calling, shooting – in most ranching situations but not all.  Yet all ranchers shared their goals to reduce losses of both livestock and wildlife and agreed that preventing losses is the best approach in all cases.

I welcome you to visit our HREC site and you can review the amazing graphic art that captured the essence of the workshop, as well as the rancher panel interviews, the presentations and more online.  Please join us for future events.

Together, we may find innovative tools and solutions and keep ranching viable in our communities to prevent further fragmentation and conversion to other uses, saving both livestock and wildlife.

Posted on Friday, September 8, 2017 at 11:09 AM

Top 10 pests in gardens and landscapes and how to control them

Download the free booklet at the bottom of the page!

1. Ants

Most people deal with ants around their home at some point. Because most ants live outdoors, focus efforts on keeping ants from entering buildings by caulking entryways. Follow good sanitation practices to make your home less attractive to ants. Spraying ants inside the home will not prevent more ants from entering. Use baits to control the ant colony. Pesticide baits work by attracting worker ants who then take the poison back to the nest where the entire colony, including queens, can be killed. In the landscape, ants protect honeydew-producing pest insects from predators, so use sticky barriers or insecticide baits to keep ants out of trees and shrubs.

 

2. Aphids

Aphids can curl leaves and produce sticky honeydew, but they rarely kill plants and you usually can wash them off with water. When aphid numbers get high, natural enemies such as lady beetles (lady bugs), lacewings, syrphid fly larvae, soldier beetles and others frequently feed on them, eliminating the need for pesticides. Protect these good bugs by avoiding the use of insecticides that can be toxic to a broad variety of insects. Ants protect aphids from these natural enemies, so keep ants away from your garden as well. When pesticides are necessary, use less toxic products such as insecticidal soaps and oils.

 

3. Asian citrus psyllid and Huanglongbing disease

The Asian citrus psyllid (ACP) and the deadly bacterial disease it spreads, Huanglongbing (HLB), threaten citrus trees in backyards and on farms. There is no cure or effective control method for HLB disease.  All types of citrus—including oranges, grapefruit, lemons, and mandarins—are affected as well as a few closely related ornamentals. ACP and HLB have already devastated the Florida citrus industry, and now that it is in the Western U.S. it is threatening the California citrus industry as well.

 

4. Gophers

Gophers are small burrowing rodents that feed on roots of many types of plants. A single gopher can ruin a garden in a short time, and gopher gnawing can damage irrigation lines and sprinkler systems. In lawns, their mounds are unsightly and interfere with mowing. Early detection is critical to prevent damage. Use both traps and underground fencing to manage gopher problems. Toxic baits are available but can pose threats to wildlife, pets, and children, especially in backyard situations.

 

5. Leaf-feeding caterpillars

Caterpillars, which are the larvae of butterflies and moths, damage plants by chewing on leaves, flowers, shoots, and fruit. Caterpillars in fruit or wood can be difficult to manage because they are hidden most of their life and can cause serious damage even when numbers are low. However, many plants, especially perennials, can tolerate substantial leaf damage, so a few leaf-feeding caterpillars often aren't a concern. Handpicking and beneficial predators and parasites often provide sufficient control. Look for feeding holes, excrement, webbed or rolled leaves, caterpillars, eggs, and good bugs.

 

6. Peach leaf curl

Peach leaf curl is a fungal disease that affects only peach and nectarine trees. Distorted, reddened foliage in the spring is a distinctive symptom. New leaves and shoots thicken and pucker and later may die and fall off. An infection that continues untreated for several years can lead to a tree's decline. To prevent peach leaf curl, treat peach and nectarine trees with a copper fungicide every year after leaves fall. After symptoms appear in the spring, any treatment will not be effective. When planting new trees, consider buying peach tree varieties that are resistant to the disease.

 

7. Rats

Rats eat and contaminate food, garden produce, and fruit, and transmit diseases to humans and pets. Manage rats by removing food and shelter, eliminating entryways into buildings, and trapping. Snap traps are the safest, most effective, and most economical way to trap rats. For Norway rats, place traps close to walls, behind objects, in dark corners, and in places where you have found rat droppings. For roof rats, place traps in off-the-ground locations such as ledges, shelves, branches, fences, pipes, or overhead beams. Ensure traps are out of reach of children and pets.

 

8. Scales

Scale insects suck plant juices and are pests of many trees and shrubs. Infestations can cause yellowing or premature dropping of leaves, sticky honeydew, and blackish sooty mold. Plant parts can distort or die back, depending on the species and abundance of scales. Most plants tolerate low to moderate numbers of scales. Provide plants with proper cultural care, especially irrigation. Encourage scale predators such as lady beetles or lacewings and look for parasite emergence holes in scale covers. Use sticky barriers or insecticide baits to selectively control scale-tending ants. Consider replacing problem-prone plants because most scales are highly specific to certain plants.

 

9. Snails and slugs

These slimy mollusks emerge from hiding at night and chew holes in leaves and flowers of many succulent garden plants and fruit. Management requires a vigilant and integrated approach that includes eliminating moisture and hiding spots, trapping, setting up barriers, and handpicking. Regularly remove snails from shelters you can't eliminate such as low ledges on fences, undersides of decks, and meter boxes. Place traps in your garden and dispose of trapped snails and slugs daily. Reduce moist surfaces by switching to drip irrigation or watering in the morning rather than later in the day. Consider snail-proof plants such as impatiens, geraniums, begonias, lantana, nasturtiums, and many plants with stiff leaves and highly scented foliage such as sage, rosemary, and lavender.

 

10. Weeds in landscapes

Prevent weed invasions in new beds with good site preparation. Keep weeds out with an integrated program that includes competitive plants, mulches, and hand removal. Be particularly vigilant about removing aggressive perennial weeds. You rarely should need herbicides in established landscape plantings. Mulches prevent weed seed germination by blocking sunlight. Remove small weeds by hand before they flower and set seed. Use shallow cultivation or hoeing to remove annual weeds from ornamental plantings. Only use herbicides for special-problem situations before establishing new plantings or for difficult-to-control perennial weeds.

 

To see all of the University of California's Statewide Integrated Pest Management Program's information on home, garden, and landscape pests, visit http://www.ipm.ucanr.edu/PMG/menu.homegarden.html

For other short pest “Quick Tips” like the ten above, see http://www.ipm.ucanr.edu/QT/

 To read even more in-depth, peer-reviewed information on many other common home and landscape pests in California, see the Pest Notes series at http://www.ipm.ucanr.edu/PMG/PESTNOTES/index.html

Download your free UC IPM Quick Tips Booklet of the Top Ten Pests in Gardens and Landscapes and How to Control Them with the link below! 

Posted on Friday, June 10, 2016 at 12:30 PM
  • Author: Tyler Ash

Information on managing invasive weeds and other pests available in new edition of Forest and Right-of-Way Pest Control

Brooms are shrubs introduced into North America from Europe in the mid-1800s. Common species include Scotch broom (Cytisus scoparius) and Portuguese broom (Cytisus striatus). Brooms initially were introduced as ornamentals, but then used extensively for erosion control along roadsides and in mined areas.

Now throughout California forests, roadsides, and wildlands they are weeds that increase the risk of wildfire and crowd out desirable vegetation. They form impenetrable thickets that invade other vegetation, shade out tree seedlings, and make reforestation difficult. They burn readily, increase the intensity of fire, and carry fire to the tree canopy. They are toxic to cattle and horses and unpalatable to most wildlife. Brooms produce abundant, long-lived seed and are able to fix atmospheric nitrogen, giving them competitive advantage over native plants.

Learn more about the management of weeds and other pests in Forest and Right-of-Way Pest Control second edition. Knowledge expectations and review questions to help professionals pass DPR's tough applicator certification examinations are one of many new features in this edition. Use this book as your guide to safe and effective pest management on public and private forests, tree plantations and nurseries, and along roads, railways, utility corridors, biking and hiking trails, and other rights-of-way. The book's 190 photos and illustrations, 56 tables and sidebars, and 11 main chapters aid in pest identification and problem diagnosis and provide users with pesticide and nonpesticide solutions.

Invasive species that create a dangerous wildfire hazard and crowd out desirable vegetation and wildlife are examples of why this book emphasizes vegetation management and pesticide handling, including correct equipment calibration and effective herbicide application. The second edition also provides broader coverage of insects, plant pathogens, vertebrate pests, and the various practices to manage them, recognizing that lands commonly have multiple uses and when and how pests are managed depends on many considerations with sometimes conflicting goals.

Experts with Cal-Fire, Caltrans, PG&E, USDA Forest Service, private industry, the University of California (UC) Berkeley and Davis campuses, UC County Cooperative Extension offices, and the California Department of Pesticide Regulation (DPR) contributed to Forest and Right-of-Way Pest Control, prepared by UC ANR's Statewide Integrated Pest Management Program.

Forest and Right-of-Way Pest Control is available for $35 online in the UC ANR Catalog. The table of contents and more information about the book are available on the UC IPM website. You can also preview and electronically search the contents on Google Books.

 

Posted on Monday, March 3, 2014 at 4:11 PM
  • Author: Steve Dreistadt
 
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