Source: VIRGINIA POLYTECHNIC INSTITUTE submitted to NRP
INTEGRATED PEST MANAGEMENT FOR CEREAL APHID AND BARLEY YELLOW DWARF CONTROL IN THE EASTERN AND SOUTHEASTERN US
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1032280
Grant No.
2024-68008-42760
Cumulative Award Amt.
$290,000.00
Proposal No.
2023-09589
Multistate No.
(N/A)
Project Start Date
Jul 1, 2024
Project End Date
Jun 30, 2027
Grant Year
2024
Program Code
[A1701]- Critical Agricultural Research and Extension: CARE
Recipient Organization
VIRGINIA POLYTECHNIC INSTITUTE
(N/A)
BLACKSBURG,VA 24061
Performing Department
(N/A)
Non Technical Summary
Barley yellow dwarf virus is transmitted by several species of cereal aphids and has been a threat to winter wheat in the southeastern USA in recent years. Integrated pest management (IPM) is the most effective approach to managing BYDV and aphids. However, the recommended strategies in the southeastern USA (i.e., planting date, seed treatment, and/or timing of foliar insecticide application) are based on information generated more than two decades ago, which no longer fit to our current climate patterns or best management practices. This proposal aims to provide research-based support for the effective management of BYDV and cereal aphids in winter wheat in the southeastern United States and develop much-needed, up-to-date educational material to prevent the unnecessary application of insecticides and promote the implementation of IPM. We will also provide estimates of expected revenue associated with implementing each practice and develop a calculator and educational material to assist producers with the decision-making process.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21615991070100%
Knowledge Area
216 - Integrated Pest Management Systems;

Subject Of Investigation
1599 - Grain crops, general/other;

Field Of Science
1070 - Ecology;
Goals / Objectives
The overarching goal of this project is to provide research-based support for the effective management of cereal aphids and BYDV in winter wheat (and other small grains) in the southeastern United States and to develop much-needed up-to-date educational material and workshops to prevent unnecessary application of insecticides and promote the implementation of IPM. There are four specific project objectives that are interconnected:i. Test the natural vegetation in and around fields to identify regional reservoirs of BYDV and aphid vectors in Virginia,ii. Establish field plots to determine and demonstrate appropriate practices to minimize BYDV;ii.1. Demonstrate the effectiveness of planting time in evading BYDV infection.ii.2. Compare the efficacy of neonicotinoid seed treatment and foliar pyrethroid applications in managing cereal aphids and BYDV.iii. Determine yield loss due to BYDV and estimate farm profitability implications of BYDV damage and adoption of the control practices evaluated through Obj. ii. iv. Develop educational material and conduct workshops to increase grower awareness of recommended management practices for controlling BYDV.
Project Methods
Objective 1: Identifying regional reservoirs of BYDV and aphid vectors. We will sample foliar tissue from grasses in grazing land and the adjacent winter wheat (or other cultivated small grains) to identify potential virus reservoirs. Sampling will cover areas known for frequent BYDV outbreaks as well as areas where BYDV occurrence was not reported in 2021 and 2022 (as control fields)..Sampling will be conducted twice in each year of the project, once in September and once in March. Each year, at least 40 winter wheat fields across Virginia, either adjacent to forage grasses or to other non-grass crops (primarily soybean and tobacco) at the time of planting, will be considered for this objective. Sampling consists of inspecting plants and counting cereal aphids and removing plants from a one square foot area every 50 feet, for a maximum of 200 ft of the wheat fields and the neighboring grazing land on two rows that are 100 ft apart (a total of 20, 1-ft samplings from the wheat field and its neighboring grazing land). The first row will be at least 10-ft away from the edge of the field (or grazing land). The collected plants will all be transported or shipped overnight to the Southern Piedmont Entomology Laboratory in Blackstone, VA, and evaluated for BYDV presence using the quantitative reverse transcription polymerase chain reaction (RT-qPCR) test. To detect and quantify BYDV, 100 mg of leaf tissue will be removed from two fully expanded young leaves. RNA extractions will be performed using a Qiagen RNeasy plant mini kit. cDNA synthesis and BYDV titer quantification will be carried out by a Luna® Universal One-Step RT-qPCR Kit (New England Biolabs) with forward and reverse primers according to Balaji et al. (2003). The percentage of plants found positive for the BYDV will be estimated for each of the collected plant species. A generalized linear mixed model with a nonlinear distribution (TBD based on data) will be used to predict whether BYDV incidence in a wheat field is influenced by its proximity to grazing land. Spearman rank correlation can be used to examine the relationship between disease incidence and aphid pressure. In addition, plant species that may serve as BYDV reservoirs (and alternative cereal aphid hosts) will be identified. Species identification will be sent to Virginia Tech Weed Identification Laboratory for confirmation.Objective 2: Establish field plots to determine and demonstrate appropriate practices to minimize BYDV.Two-year field experiments will be conducted on the research farm of Virginia Tech's Southern Piedmont Agricultural Research and Extension Center in Blackstone, VA, as well as on Leslie Farms located in Amelia, VA (see letter of collaboration and support). In each location, there will be three experimental fields, 200 feet apart, planted mid-September ('early planting'), mid- to late-October (commonly practiced; hereafter, 'optimal planting'), or late-November ('late planting'). Plots planted early, optimally, and late are separated to reduce the risk of aphid movement from early-planted plots to plots planted later into the fall. The commonly used winter wheat variety in the southeast region, Shirley, will be used in both locations. For each location, there will be six treatments (including the control) per planting time: 1) untreated control, 2) neonicotinoid seed treatment, 3) fall broad-spectrum foliar insecticide application (upon aphid detection), 4) spring broad-spectrum foliar insecticide application (upon aphid detection), 5) neonicotinoid seed treatment + fall foliar insecticide application, 6) neonicotinoid seed treatment + spring foliar insecticide application. Treatments will be replicated 4 times within each planting time arranged in a randomized complete block design (24 plots per planting time/location; 144 plots, total). In both locations, plots will be 5 × 30 ft, planted with a 5-ft Zurn D82 planter. Replications will be planted 10 feet apart to maximize exposure to incoming aphids from reservoirs (as opposed to between plot movements early in the season). The spaces between experimental fields and plots will remain fallow. A Zurn 150 combine will be used to harvest all plots and record yield.Each plot will be monitored and sampled every ten days starting day five post-germination (80% emergence) in the fall and ending in early April. Monitoring includes counting the number of aphids per 5 randomly selected plants perpendicularly across each plot and removing the aboveground tissues for BYDV testing. RNA will be extracted, and the number of BYDV copy numbers (titer) will be quantified using RT-qPCR. A generalized linear mixed model (repeated measure) will be used to compare BYDV incidence (percent positive) and aphid numbers among treatments within each planting date and across planting dates over time. A generalized linear mixed model assuming a normal distribution and an identity link function will be used to analyze yield data among treatments.Objective 3: Determine yield loss due to BYDV and estimate farm profitability implications of BYDV damage and adoption of the control practices evaluated in objective ii. We will estimate the profitability implications associated with each IPM strategy evaluated in objective 2. To estimate revenue losses to BYDV, we will use yield and pesticide usage data collected from the implementation of the plot trials described under objective 2 in both years of the study. Specifically, to obtain estimates of expected revenue, the yield data from the trials implemented under objective 2 will be combined with wheat market prices to estimate revenues associated with each treatment. For production costs, existing enterprise budgets for wheat production in the eastern and southeastern US will be used as a baseline regarding fertilizer, pesticides, labor, and equipment-related usage in winter wheat production. These enterprise budgets will then be adjusted to reflect changes in the usage of any production-related inputs associated with the investigated IPM strategies. Costs associated with inputs needed for the implementation of the IPM strategies and that were not encompassed into the production-related assumptions for the baseline enterprise budgets will be obtained from project collaborators who buy materials for implementing the field trials. Since the field trials will be implemented over the course of 3 years, the profitability estimates for the first year will be updated in years 2 and 3 to reflect updated yield-to-BYDV infestation relationship information and associated yield and price variability as observed in the field trial and price data. Based on the estimated variability of yields and prices, and hence, profitability, a "breakeven analysis" will be implemented in each year that field trials are implemented. Multiple years of data will provide more realistic ranges for yields and prices that can be expected under various production conditions and wheat market conditions.

Progress 07/01/24 to 06/30/25

Outputs
Target Audience:Taregt Audience during this period included: - Crop and livestock producers (specially small grain producers) - Graduate and Undergraduate Students - Ag Extension Agents and Educators - Farm and Technical staff - Researchers and Scientists at the national and international stages - Ag Industry (consultants, Chemical reps, seed) - General public (through news releases) Changes/Problems:Heavy rain affected early planting in one location, but we managed to seed a week later. The second foliar spray was not feasible in December-seeded plots due to freezing. Therefore, foliar spray comparisons may be lacking in late-planted plots. For these comparisons, the focus will be on the effects of planting date and seed treatment on yield, aphid numbers, and BYDV incidence. What opportunities for training and professional development has the project provided?One PhD student is being trained through this project. This project provided an opportunity to train a postgraduate technical support. One undergraduate student will be trained through this project by the next reporting period. In addition, eight fam crew members learned about BYDV, cereal aphids, and different management practices. The regional producers who attended our workshop are now familiar with BYDV symptoms in the field and recommended management practices. How have the results been disseminated to communities of interest?The results have been communicated through handouts, presentations, and a peer-reviewed publication. Our research activities have been publicized through images posted on social media platforms, including Instagram and Facebook. Funding success was initially announced through VT News and the Southern Piedmont AREC newsletter. What do you plan to do during the next reporting period to accomplish the goals?Harvesting our plots will be the upcoming activity. All BYDV testing from Year 1 of this project is expected to be completed by the end of August 2025. The harvest and BYDV data will be analyzed and used in the publication of an Extension publication. This study will be repeated in the fall, with plant tissue samplings conducted twice in the fall and once in the spring. The first- and second-year data will be pooled and are expected to result in a second peer-reviewed publication. Two more field days are expected for the second year of this project. One undergraduate student will be trained by the next growing season.

Impacts
What was accomplished under these goals? Test the natural vegetation in and around fields to identify regional reservoirs of BYDV and aphid vectors in Virginia: This is an ongoing effort. To date, we have sampled more than 30 sites. In 2024, 100% of the small grain samples submitted by Virginia producers tested positive for BYDV. Samples collected and submitted in 2025 are being evaluated. 10 sites with the small grain-grazing land interface have been identified and sampled. Growers are being contacted to identify additional sites for fall sampling. Experiments were also conducted to examine aphid and BYDV interactions with different types of tall fescue, the most common forage grass. Establish field plots to determine and demonstrate appropriate practices to minimize BYDV; Demonstration plots have been established in three locations: 1) Southern Piedmont Agricultural Research and Extension Center (AREC) near Blackstone, VA, 2) Eastern Virginia AREC, Warsaw, VA, and 3) Blanton Farm in Amelia Court House, VA. There are three planting dates in each location, with 32 plots per planting date per location. Heavy BYDV infections and cereal aphid infestations were detected at the Southern Piedmont AREC and the Eastern Virginia AREC locations. Blanton Farm had aphid infestations, but a limited number of plants are showing symptoms. All plots have been scored for aphid presence before the first foliar application and 1-2 weeks after foliar applications. Fall samples have also been collected from 5 plants in each plot to evaluate BYDV infection. Scorings for aphids and sampling for BYDV evaluation were also completed in the spring to determine the extent of spring infections. Demonstrate the effectiveness of planting time in evading BYDV infection. So far, our results indicate that early planted plots have relatively higher aphid numbers compared to optimally and late-planted plots. Although very few aphids were found on late-seeded plants, yield data are needed to examine the practicality of late planting (i.e., late November and early December). Late-planted plots are shorter and thinner than the early-planted and optimally-planted plots in all locations. Compare the efficacy of neonicotinoid seed treatment and foliar pyrethroid applications in managing cereal aphids and BYDV. The seed treatment gaucho was very effective in reducing aphid numbers and protecting wheat against aphids. This effect disappeared in the spring, a result which was expected since the effect of seed treatment fades away over time. Although seed treatment was effective in reducing aphid numbers in early planted plots, it failed to protect plants from BYDV. Therefore, early seeding (early to mid-October) should be avoided. Late October and early to mid-November are recommended seeding times for Eastern Virginia and the Southern Piedmont region of Virginia, respectively. A similar pattern, with gaucho being effective in reducing aphid numbers, is observed for plots seeded at the optimal time (late-October through mid-November). BYDV testing is in progress for optimal and late planting dates. Determine yield loss due to BYDV and estimate farm profitability implications of BYDV damage and adoption of the control practices evaluated through Obj. ii. Plots will be harvested by mid-June, and data will be analyzed after harvest. Develop educational material and conduct workshops to increase grower awareness of recommended management practices for controlling BYDV. So far, during our events, we have provided stakeholders with handouts that describe BYDV, cereal aphid vectors, current best management practices, and reported our research progress. A numbered Extension publication is in preparation and will be submitted after the harvest data is analyzed.

Publications

  • Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: Parizad, S. & A. Rashed. Impact of natural vegetation on barley yellow dwarf virus (BYDV) epidemiology. Entomological Society of America, Pheonix, November 2024.
  • Type: Other Status: Published Year Published: 2025 Citation: Rashed, A. & Parizad, S. Southern Piedmont AREC barley yellow dwarf field day, Blackstone, VA, May 2025. (handouts provided)
  • Type: Other Status: Published Year Published: 2025 Citation: Rashed, A. & Parizad, S. Eastern Virginia AREC Small Grains Field Day, Warsaw, VA, May 2025. (handouts provided)
  • Type: Other Status: Other Year Published: 2024 Citation: New USDA grant helps Virginia Tech researchers combat barley yellow dwarf virus in southeastern winter wheat. By Suzanne Pruitt https://news.vt.edu/articles/2024/09/USDA-grant-barley-yellow-dwarf-virus.html
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2025 Citation: Parizad, S. & A. Rashed. 2025. Can barley yellow dwarf virus (BYDV) incidence in winter wheat be influenced by endophyte-tall fescue association in grazing lands? Entomologia Generalis, 45: 473-480.