Project Overview
Exploring management of threecornered alfalfa hopper in mid-Atlantic US soybean
Commodities
- Agronomic: soybeans
Target Pests
- Target Pests: insects
Practices
- Pest Management: chemical control, cultural control, monitoring/scouting, pesticide application timing, pesticides
Proposal abstract:
i) Threecornered alfalfa hopper infestations are a yearly occurrence in soybeans grown in Virginia’s piedmont region causing economic damage and increasing insecticide use. Additional widespread infestations, and resulting injury, were reported from Virginia’s central and coastal regions in 2020, potentially indicating a range expansion. Threecornered alfalfa hopper injury to seedling or early vegetative soybean can cause plants to break and lodge, and injury is often not detected until stand loss occurs and no remedial action is possible. Piedmont farmers are increasing transitioning from tobacco to soybean production and are in the process of learning pest management strategies and costs. There is a definite need for funding to improve soybean IPM for this pest in Virginia and other states where this pest is, or will become, problematic. The timing and extent of infestations in the mid-Atlantic, and their damage-causing potential, is poorly understood. The proposed research will take the first steps to characterize infestation timing, yield-damaging potential, insecticide control plans, and cultural control strategies. Soybean entomologist PD Taylor and soybean agronomist Co-PD Holshouser are dedicated to the success of this project. We anticipate that our findings will provide valuable and readily applicable recommendations and form the basis of a more-comprehensive IPM plan.
ii) Multiple farmers, through their representative Virginia Cooperative Extension Agriculture and Natural Resources Agents, support this research and have offered land for experiments. Our proposed project will include field monitoring and field experiments. Virginia soybean fields will be sampled for insects weekly from soybean emergence to maturity using traps and sweep nets. Experiments will be conducted to determine the effect, if any, of seed applied insecticides and the timing of broadcast insecticides on the target pest and other pest and beneficial insects. We will also measure the effect of seeding rate, a planting practice that is easily adjusted by farmers and one that may mitigate the extent of economic damage from injured plants. In all experiments, populations of pest and beneficial insects, plant injury, and yield will be measured and compared.
iii) Timely alerts will be shared on our blog. Any recommendations that arise will be shared in peer-refereed manuscripts, extension publications, in production meetings and field days, and at scientific conferences.
Project objectives from proposal:
|
Planned Outputs |
Anticipated Outcomes |
Problem or priority targeted |
|
1. Extension |
||
|
Survey stakeholders (using questionnaires at annual meetings) to determine the awareness/extent of this problem (i.e., acres scouted, acres sprayed, ability to identify the insect, ability to perform scouting activities, and ability to recognize plant injury). |
In the short term, these surveys will provide the data and information on how soybean producers and crop advisors perceive the problem and their current management practices. Results will help design initial research and extension efforts.
In the medium term, these data will be used to track trends in IPM adoption (i.e., How can the program be improved or changed?).
In the long term, these data will serve as the baseline on the impact of a management plan (Are growers practicing IPM for this pest? Is there a reduction in insecticide sprays? Is there an economic benefit for the producer? Are IPM programs reaching the maximum number of people? Are there underserved regions or room for improvement?). |
Producers are applying insecticides that may be unnecessary because 1) the pest is not there, or 2) the sprays are mistimed to provide effective control. |
|
2. Research |
||
|
Monitor for threecornered alfalfa hopper in multiple locations in Virginia. Data will be used to estimate infestation timing. This information will be shared weekly with stakeholders using the Virginia Ag Pest & Crop Advisory (http://blogs.ext.vt.edu/ag-pest-advisory/). |
In the short-term, these data will be used to inform growers on the likelihood of infestations in real-time; thus encouraging timely scouting efforts. This potentially remedies two situations: 1) fields that are being sprayed with insecticides in the absence of bugs and 2) fields that are being damaged by bugs in the absence of insecticide sprays. In the medium term, these data will inform on new research areas/priorities and be used to obtain further funding. In the long-term, these data will inform tools such as risk assessment models. |
There is currently no regionally specific information on the timing of damaging populations in Mid-Atlantic US soybean. |
|
Conduct experiments to determine the effect of 1) foliar and seed applied insecticides, and 2) soybean planting density on threecornered alfalfa hopper injury. |
In the short term, these data will provide valuable early information to share with stakeholders at meetings and field days to both 1) increase knowledge of the situation, and 2) discourage any unnecessary or ineffective insecticide sprays.
In the medium term, these data will inform additional research gaps/opportunities (i.e., other cultural practices like cover cropping). Results from these experiments will be used to obtain further funding.
In the long term, these data will be used to create an IPM management plan (scouting information, management recommendations) and create informational/educational aides (pest management guides, brochures, up-to-date online publications) to change behavior (insecticide usage) of producers. |
There is currently no regionally specific IPM plan for threecornered alfalfa hopper in mid-Atlantic US soybean. The relationship between infestation timing, plant injury, and economic damage is unknown. |
