These projects were funded by the Western IPM Center's 2018 grants. Project directors are listed first.
For more details about a project, or to find one not listed here, use the search function on the IPM Projects Interagency Database
Outreach and Implementation
The Identification and Control of Invasive Plants in Arizona
Elise Gornish and Larry Howery, University of Arizona
As a result of the invasion and subsequent negative impacts of non-native plant species across Arizona, many groups have developed noxious plant lists, including state agencies and non-profit organizations. Despite the abundance of these invasive species lists, missing from all of these resources is an equivalent or associated resource guide for managing high-priority weeds based on the results of field trials and published as agency reports or peer-reviewed studies. A comprehensive management guide that enumerates promising IPM strategies to control high-priority weeds is needed to address the demand of Arizona’s diverse stakeholder group. We propose to update an existing guide of invasive plants in Arizona, which has not been significantly updated since 2009. Like all outreach products listing invasive plant names and characteristics in Arizona, the existing guide does not currently provide IPM information for any species.
To update the guide, we plan to (1) ensure that the current listing is up-to-date and includes emerging invasives, (2) identify and organize all of the peer-reviewed and grey literature that describes weed-control experiments on the species highlighted in our guide and, (3) summarize this data in the guide to provide management recommendations. Although targeted for individuals who live and work in Arizona, the guide will also be useful for Western stakeholders in general because many of the plant species that prove to be particularly invasive in Arizona ecosystems are problematic elsewhere. We will deliver guide to agency offices and make it available on multiple websites online.
Low-Cost IPM for Medusahead and a Cost-Benefit Framework to Support Adoption
Jeremy James and Josh Davey, University of California, Division of Agriculture and Natural Resources; Matt Rinella, USDA-ARS Montana
Rangelands represent the largest agroecosystem in the West, serving a critical role in the U.S. livestock industry and providing society a suite of essential ecosystem services. Medusahead, one of most serious rangeland plant pests, has progressively spread across a six state area, drastically reducing forage production and biodiversity while greatly increasing the frequency of catastrophic fires. Over the last five years our project team has focused on developing a novel low-cost IPM strategy for medusahead and quantifying economic relationships between pest abundance and livestock production. The goal of this proposal is to build off of these advances and develop an outreach program that catalyzes adoption of IPM programs for medusahead.
To address this goal we will partner with a team of potential early-adopters and (1) establish management-scale demonstrations of our low-cost tools involving timed grazing and a novel application of a growth regulating herbicide to sterilize medusahead seed (2) develop an online calculator that allows producers to enter ranch-specific information to estimate medusahead impacts on revenues and identify when adoption of our low-cost IPM tools will allow ranchers to break even or increase profits and (3) have our early-adopter team evaluate our demonstration results and cost-benefit framework supported by the online calculator to identify regional opportunities to initiate adoption. High treatment costs and uncertainty around treatment benefits has prevented IPM from being adopted on rangeland at any measurable scale. This project overcomes these barriers providing a major opportunity to recover essential ecological an economic function of rangeland across the West.
Enhancing IPM by Integration of Chemical and Biological Controls through Assessment of Selectivity of Chemistries and Function of Biocontrol
Isadora Bordini, Peter Ellsworth and Al Fournier, University of Arizona; Steven Naranjo, USDA-ARS Arizona
In this project initiation project, we will develop better information about effects of currently registered and experimental whitefly, Bemisia tabaci, and Lygus bug insecticides on natural enemies, and investigate the effect of plot size in this type of study. We will conduct a non-target organism trial at Maricopa Agricultural Center, and we will examine selectivity of candidate insecticides (obj. 1) and effects of plot size on population dynamics and predation rates of whitefly natural enemies in cotton (obj. 2). We will conduct outreach to growers, pest managers and the scientific community. We will sample pests and natural enemies using established methods, and examine predation rates.
Data from this project will inform grower insecticide selection to minimize disruption of natural enemies, preserve biocontrol, and maintain chemical options for resistance management. Also, the information provided on plot size will help in determining the validity of conclusions from field trials of this type, and may improve interpretation of ecological data for mobile insects by IPM scientists. This project addresses stakeholder needs identified by the scientific community and growers, addressing Western IPM PMSP priorities of maintaining a variety of chemical controls, including selective insecticides, to preserve effective biological control and for resistance management for key pests. We will directly engage tribal pest managers from Gila River Indian Community and Ak Chin Indian Community. This project will advance IPM by directly promoting integration of chemical and biological control as well as the conservation of natural enemies, which are priorities expressed by the scientific and practitioner community.
Testing Community Functional Composition of Vegetation Buffers to Improve Post-Fire Invasion Resistance of Coastal Sage Scrub
Loralee Larios, Travis Bean and Noah Teller, University of California, Riverside; Elise Gornish, University of Arizona
Disturbances to ecosystems often provide opportunities for invasive species to establish and spread. The Canyon fires of 2017 burned over 11,800 acres in Chino Hills State Park, including threatened Coastal Sage Scrub (CSS) habitat that is home to numerous endemic species. Mediterranean annual grasses are present and spreading in patches nearby, and due to their prolific forage production their presence on the landscape threatens to further accelerate and intensify wildfires in the future and competitively exclude native vegetation. Reestablishing native vegetation may provide invasion resistance and prevent type conversion of CSS to annual grassland.
We propose to study how functional composition of species mixes used for seeding in bulldozer lines may constrain invasion, allowing interior portions of CSS habitat to regenerate sufficiently to reestablish natural invasion resistance. A greenhouse experiment will characterize traits of 20 native and five invasive species across multiple individuals and life stages. Traits include specific leaf area, specific root area, relative growth rate, seed mass, and phenology. We will create two distinct seed mixes, one with low functional diversity and traits as similar as possible to invaders, and the other with maximum functional diversity. We will measure relative abundance of plant species in bulldozer lines and colonizing nearby. We hypothesize that the low-dispersion community will more effectively suppress invasive species in the first year due to similar resource needs and reproductive strategies, but that the high-dispersion community will be more effective in the second year due to increased two-year survival of native species.
Utilizing Unmanned Aerial Vehicle Technology to Assess Pest and Disease Pressure in Berry Crops
Jason Myer, Northwest Berry Foundation; David Bryla, USDA-ARS Oregon
Commercial UAV (Unmanned Aerial Vehicle) technology has opened many opportunities for growers. Employing high-resolution and multispectral cameras, it is now possible to see fields in unprecedented detail. This project aims to utilize UAV-derived field imagery to assess pests and diseases in berry crops. Working with Northwest berry growers, fields with a known presence of pests likely to be visible in aerial imagery will be mapped. These pests include blueberry shock virus (BlShV), Silver Leaf (Chondrostereum purpureum), Phytophthora and Armillaria (Armillaria mellea) in blueberries; in red raspberries- Phytophthora root rots, yellow rust (Phragmidium rubi-idaei), raspberry bushy dwarf virus (RBDV) and spider mites; in black raspberries-- Verticillium (Verticillium dahlia) and black raspberry necrosis virus (BRNV); in strawberries-- spider mites, strawberry crown moth, and root weevils; in blackberries--raspberry bushy dwarf virus (RBDV) and blackberry rust (Phragmidium violaceum). Flights will be timed when symptoms are most evident. Imagery will be taken in RGB, red-edge, near-infrared, and infrared spectrums. Ground observation data will be overlaid onto aerial imagery to determine what pests and diseases can be identified and quantified from the imagery. The results will be disseminated through industry newsletters, grower workshops, and field demonstrations. Results will also be used to develop future projects aimed at further refining and implementing UAV technologies into standard IPM programs for berry crops.
An Integrated Weed Management Approach for Controlling Kochia in Wheat Using Physical and Cultural Tactics
Steve Young, Earl Creech and Corey Ransom, Utah State University
Weeds affect production systems by reducing yields, impeding harvest operations, and increasing the soil weed seed bank. In conventional systems, herbicides are most commonly used to control weeds, yet efficacy is declining for some of the most challenging weeds, such as kochia. Therefore, finding alternative ways to enhance the competitive ability of crops is critical in limiting the growth of kochia and its detrimental effects on production systems.
In this one-year preliminary study, field experiments will be conducted using 1) cover crops and mulches to suppress kochia, 2) planting dates to avoid kochia emergence and 3) seeding rates to provide wheat with a competitive advantage. Grower farms and university land with moderate-to-heavy infestations of kochia will be used as sites. Non-destructive measurements (e.g., efficacy) will be taken during active crop growth and destructive samples (e.g., biomass) will be taken at the end of the season. Through this study, a combination of physical tactics that are matched with a set of cultural tactics will be identified specifically for controlling kochia in the wheat-growing regions of Utah and southern Idaho. As an outcome, growers will be surveyed at a late summer field day to determine the value of the approach and to develop follow-up studies. The goals of the project align well with the missions of the Western IPM Center, which is to foster the development and adoption of integrated pest management, the center’s “Invasive Species in the West" Signature Program, and the WERA-77 "Managing Invasive Weeds in Wheat” Working Group.
Novel Control of the Potato Zebra Chip Pathogen and its Psyllid Vector Using FANA Antisense Oligonucleotide Gene Silencing
William Cooper and Kylie Swisher, USDA-ARS Washington; Wayne Hunter, USDA-ARS Florida
Zebra chip disease causes yield losses to potato production in the Western United States. The pathogen that causes zebra chip, "Candidatus Liberibacter solanacearum", is transmitted to potato by the potato psyllid. There are no methods to directly control zebra chip, so growers rely on calendar-day based insecticide applications to reduce populations of the vector. The overall goal of our proposal is to demonstrate that FANA-based gene silencing therapy can provide a novel approach for managing the zebra chip pathogen and its psyllid vector. FANA gene silencing does not involve genetically modified organisms like other gene-silencing therapies, and is highly specific to target organisms.
Specific objectives are to use laboratory and greenhouse assays to determine if FANA products can 1) reduce pathogen titers and development of zebra chip symptoms in potato, 2) reduce pathogen titers in psyllids, and 3) decrease vector performance. Results will provide proof-of-concept for the use of FANA technology to control insect pests and pathogens of crops. Completion of this one-year project initiation study will lead to future trials examining the efficacy of treatments under field-management conditions, and to the development of this technology against related pathogens and psyllids occurring on other crops or other pests and pathogens of potato. Further development of FANA technology beyond this 1-year project could lead to development of novel tools to manage plant pests and pathogens, and substantially reduce or eliminate the use of calendar-based pesticide applications used to manage challenging pests and pathogens such as potato psyllid and zebra chip.
Informed Risks and Information-Driven Decision Making for Spider Mites
Ann George, Washington Hop Commission; Doug Walsh and Jennifer Sherman, Washington State University; David Gent, USDA-ARS Oregon
The twospotted spider mite, Tetranychus urticae Koch, is pest of numerous plants worldwide. Hop is a preferred host of spider mites, and spider mites are an annual problem in most commercial growing regions worldwide. Management of this pest is increasingly difficult due to widespread resistance to multiple miticides. A central component of a successful IPM system is the ability to make crop management decisions with relative certainty that the management actions will avoid crop damage and minimize economic risk. However, action thresholds for spider mites supported by empirical data do not exist.
Drawing from extensive historical data sets, we proposed to: 1. Identify risk factors for spider mite damage to hop cones and formalize risk factors into a decision aid to estimate the likelihood of crop damage. 2. Develop and deliver a stakeholder-driven outreach program that explains, integrates, and demonstrates new concepts for spider mite management to producers and their advisers. The association of key predator species and cost of management errors will be considered explicitly in a decision theoretic framework to make this information fully transparent to users and considered in setting treatment thresholds. This initiating project aligns perfectly with stakeholder priorities articulated in the 2015 Pest Management Strategic Plan for U.S. Hops, priority areas for the Western IPM Center, and the National Road Map for IPM. Successful completion of this project will provide the foundation for future work to finally develop and implement a decision aid for this important pest.