Source: UNIV OF WISCONSIN submitted to
POTATO LEAFHOPPER ECONOMIC THRESHOLDS IN ALFALFA: REVISITING INTEGRATED PEST MANAGEMENT DECISION SUPPORT FOR FORAGE IN A HIGH VALUE FIELD CROP COMMODITY ROTATION
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0219683
Grant No.
(N/A)
Project No.
WIS01410
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2009
Project End Date
Sep 30, 2013
Grant Year
(N/A)
Project Director
Cullen, E.
Recipient Organization
UNIV OF WISCONSIN
21 N PARK ST STE 6401
MADISON,WI 53715-1218
Performing Department
Entomology
Non Technical Summary
Wisconsin field and forage crops are intimately linked as alfalfa is the primary perennial legume crop in rotation with annual commodity crops. This agricultural system is undergoing rapid and unprecedented change in terms of increasing crop prices (e.g., corn, soybeans, small grains and alfalfa), the proportion of Wisconsin acreage planted to each of these crops, and resulting state and regional forage supplies. In 2007, alfalfa prices increased sharply, partly due to tight hay supplies and partly in response to rapid increase in corn costs exerting upward pressure on forage value (Mintert 2008). Although refined to incorporate the use of glandular haired, potato leafhopper-resistant alfalfa varieties (Lefko et al. 2000), land-grant university economic threshold recommendations for potato leafhopper on standard, leafhopper-susceptible varieties have not been validated or updated with field research data to reflect the current high value crop market. This Integrated Research and Extension activity is designed to update linear yield-loss models for alfalfa and potato leafhopper. Model coefficients from new field research data in Wisconsin, over multiple years with additional data points at lower potato leafhopper numbers, will be used to re-calculate the Economic Injury Level and determine if the Economic Threshold should be lowered. In addition, laboratory experiments will test the hypothesis that alfalfa weevil and alfalfa blotch leafminer parasitoids are negatively impacted by increased insecticide use for potato leafhopper in the absence of field scouting data and clientele loss of confidence in economic thresholds developed over 30 years ago. Results will be delivered to county agents, farmers, and crop advisors through UW Madison Entomology and Agronomy research/extension programs. This project will generate research-based knowledge and develop educational programs that will provide updated IPM decision support to UW Extension county agents, farmers and crop advisors allowing them to continue to benefit from highly effective potato leafhopper insecticide management tactics, while refocusing on practices to preserve long-standing biological control success for alfalfa weevil and alfalfa blotch leafminer in alfalfa.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2111640113060%
2153110113030%
2165220113010%
Goals / Objectives
Wisconsin farmers grow 2.8 million acres of alfalfa annually for dry hay bales, haylage, and new seedings. The potato leafhopper is a key insect pest of alfalfa in the North Central Region. This project focuses on potato leafhopper management in an era when high value field and forage crop markets exert pressure on a perceived need by clientele to lower economic thresholds and apply insecticide at lower pest densities. This Integrated Research and Extension activity is designed to update linear yield-loss models for alfalfa and potato leafhopper. Model coefficients from new field research data in Wisconsin, over multiple years with additional data points at lower potato leafhopper numbers, will be used to re-calculate the Economic Injury Level and determine if current plant height by potato leafhopper sweep net sample Economic Thresholds should be lowered. Laboratory experiments will test the hypothesis that alfalfa weevil and alfalfa blotch leafminer parasitoids are negatively impacted by increased insecticide use for potato leafhopper in the absence of field scouting data coupled with clientele loss of confidence in potato leafhopper economic thresholds originally developed over 30 years ago. Results will be delivered to county agents, farmers, and crop advisors through UW Madison Entomology and Agronomy research/extension programs. OBJECTIVE 1A. Implement a large-plot, multiple year (seeding plus two production years) field experiment with a standard alfalfa variety (PLH-susceptible). Determine if alfalfa yield and/or quality response to potato leafhopper feeding differs between current established economic thresholds and sub-threshold population densities. OBJECTIVE 1B. Update the linear regression yield-loss model for alfalfa and potato leafhopper. Using new model coefficients obtained in Objective 1A, recalculate the potato leafhopper Economic Injury Level with additional data points at lower potato leafhopper numbers and higher alfalfa market values. OBJECTIVE 2. Elucidate effects of sub-lethal insecticide doses and routes of exposure on Hymenopteran parasitoid species important in alfalfa biological control of insect pests other than potato leafhopper. OBJECTIVE 3. Validate field research results with on-farm demonstration plots conducted with UW Extension county agents and farmer cooperators at multiple locations throughout WI during years 3 and 4. OBJECTIVE 4. Deliver project results and recommendations to UWEX county agents, farmers, crop advisors and forage production associations. Publish peer-reviewed journal article(s) and UW-Extension A-series fact sheet; create a web page with project outcomes and revised PLH management recommendations on the UW-Extension Team Forage web site; present preliminary and final results & recommendations at the UWEX Pest Management Update and other meeting series.
Project Methods
The following hypothesis will be tested: Ho: Treating potato leafhopper (PLH) with insecticides when population densities are below established economic thresholds will not result in detectable yield loss. H1: Treating PLH with insecticides when population densities are below established economic thresholds will result in measureable, statistically significant, and economically relevant yield loss. The field experiment will be conducted at the University of Wisconsin Arlington Agricultural Research Station, Arlington, WI in Columbia County. Alfalfa will be seeded in spring 2010. This study will encompass the seeding year through completion of the second production year (36 months). To achieve robust yield loss Vs. PLH regression models for each year of the study (and respective cuttings within each year) multiple potato leafhopper economic threshold population densities will be targeted for each crop (2 cuttings seeding year, 3 cuttings thereafter). Treatments will be replicated four times, and arranged in a completely randomized block design (Cuperus et al. 1983, Lamp et al. 1985). Each plot area will be 0.25 acres with a 10 ft. untreated alfalfa border on all sides of each plot to allow isolation between plots and prevent insecticide spray drift between treatments. Initially, treatments (which are dependent upon PLH densities within a particular crop height range) will depend on natural infestations as per methods of Lamp et al. (1985) and Ragsdale et al. (2007) for similar studies with PLH in alfalfa and soybean aphid in soybeans, respectively. Pedigo's (1999) insect economic injury level linear regression method will be used to re-evaluate current potato leafhopper economic thresholds. This step is required to utilize linear regression coefficients generated through the field experiment data sets obtained in Objective 1A. Regarding Objective 3, although biological control does not play a significant role in PLH management, it is a cornerstone of alfalfa weevil and alfalfa blotch leafminer natural control within the Wisconsin alfalfa production region. Methods will be adapted from Kraiss and Cullen (2008a; 2008b) to accomplish bioassay objectives to elucidate non-target effects (insecticide residue and routes of exposure) for key biocontrol agents in the alfalfa production system.

Progress 10/01/09 to 09/30/13

Outputs
Target Audience: Target audiences include Wisconsin, Upper Midwest and U.S. forage hay producers, Extension educators and county agricultural agents, IPM researchers at land-grant universities and colleges, certified crop advisors and agribusiness professionals who serve or interact with field and forage crop growers managing potato leafhopper, insecticide treatment timing, and non-target effects of insecticide applications on field and forage cropping system pest and beneficial insects. Efforts to reach target audiences included extension and outreach field day presentations, Extension entomology newsletters, and surveys of certified crop consultants about insect IPM and potato leafhopper mangagement in alfalfa. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? 1 PhD graduate student trained on this Hatch project. Several undergraduate student hourly lab and field assistants received hands-on agricultural science training on this Hatch project. How have the results been disseminated to communities of interest? Results from the 2013 and previous years (2009-2013) were disseminated by Extension Specialist, Eileen Cullen at University of Wisconsin-Extension pest management update meetings with content delivered to over 543 certified crop advisors, agribusiness professionals, farmers, extension educators, and government agency personnel. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Alfalfa,Medicago sativaL., is one of the best quality dairy forages and as the principal forage legume in the U.S., is grown on roughly 10 million ha. Potato leafhopper,Empoasca fabaeHarris, is the most economically damaging alfalfa insect pest in the Midwest and Northeast U.S. This research reviewedE. fabaeecology, biology, and pest management strategiesin alfalfa. Results from field trials on an integrated pest management system incorporating host plant resistance and an orchard grass intercrop were studied with regard toE. fabaeresponse and alfalfa quality and yield. Additionally, in response to Wisconsin farmer observations, field and laboratory experiments were conducted to study the potential for soil fertility treatments as a pest management tool forE. fabae.Lastly, alfalfa yield loss response toE. fabaewas assessed through caged field trials to re-evaluate the current potato leafhopper economic injury level model and economic thresholds (developed over 30 years ago) for susceptible and resistant alfalfa varieties. The resulting economic thresholds demonstrate that there is no need to reduce the current economic threshold.Consistent with past research, resistant alfalfa expressed a small yield drag under low potato leafhopper populations. Resistant alfalfa consistently had greater crude protein content than susceptible alfalfa. Orchardgrass improved alfalfa yield at the first crops of the season but plots with more orchardgrass had lower yields at the last crops of each season. Orchardgrass presence consistently increased neutral detergent fiber content. No consistent potato leafhopper suppressive effect was observed in field or laboratory studies of dairy manure soil ammendment to alfalfa stands. Further work in this area should more fully address soil and manure microbial activity. Results from this project provide IPM treatment decision support for potato leafhopper in alfalfa, and validate established economic threholds on current alfalfa varieties, forage values and insecticide costs. Objective 1:Determine if alfalfa yield and/or quality response to potato leafhopper feeding damage differs between current economic thresholds and sub-threshold population densities (i.e., is it economical to treat at pest densities below current thresholds?). The economic injury level for potato leafhopper, Empoasca fabae in alfalfa was evaluated over 30 years ago. In response to increasing market value of alfalfa, farmers and consultants are interested in reducing the economic threshold for potato leafhopper in alfalfa. To address this question, caged field trials were established on two consecutive crops in 2013. A range of potato leafhopper densities infested in cages in order to create a linear regression of alfalfa yield response. Leafhopper resistant and susceptible alfalfa varieties were used for the first trial, and the second trial consisted of susceptible alfalfa only. Resistant and susceptible alfalfa did not differ in their yield response to potato leafhoppers. The slopes, or yield loss per insect, for the linear regressions of both trials were used to calculate an economic injury level with a range of current alfalfa market values and control costs. The resulting economic thresholds demonstrate that there is no need to reduce the current economic threshold. Objective 2 (modified from original proposal): Alfalfa host plant resistance and orchardgrass intercrop effects on potato leafhopper populations, yield and forage quality. In this study, potato leafhopper response to resistant alfalfa and orchardgrass intercroppings was monitored in a factorial experiment established at two research stations in WI, one site from 2010-2012 and one site for 2012. Alfalfa yield and forage quality were assessed in relation to potato leafhopper densities and whole plot factorial treatments at one site. At the same site, split plots design consisting of insecticide treatment when potato leafhopper populations reached economic threshold and half-economic threshold was employed to determine if reducing the current economic threshold will increase alfalfa yields. Potato leafhopper populations only reached economic threshold once, indicating that populations were low throughout most of this study. Potato leafhoppers were suppressed by resistant alfalfa more consistently in seeding years and the effect of orchardgrass on potato leafhoppers was minimal and inconsistent. Consistent with past research, resistant alfalfa expressed a small yield drag under low potato leafhopper populations. Resistant alfalfa consistently had greater crude protein content than susceptible alfalfa. Orchardgrass improved alfalfa yield at the first crops of the season but plots with more orchardgrass had lower yields at the last crops of each season. Orchardgrass presence consistently increased neutral detergent fiber content. Objective 3 (modified from original proposal): Potato leafhopper response to alfalfa treated with liquid dairy manure in laboratory assay and field experiments. The objective of this study was to follow up on grower anecdotal evidence in order to provide scientific data with regards to this farmer observation. Potato leafhopper response to liquid dairy manure application, synthetic N- P-K-S application and a control treatment with no soil amendment was studied in the summers of 2011 and 2012 at Arlington Agricultural Research station. In 2011, we saw that when potato leafhopper populations peaked, manure did suppress potato leafhopper populations. In 2012 we repeated the experiment in two fields at Arlington Agricultural research station. Results from one field showed an increase in potato leafhopper abundance in manure plots, before potato leafhopper populations peaked later in the summer, and no difference between treatments when populations reached peak abundance. Results from the other field show no significant difference between treatments at any point in the summer. Concurrently, laboratory assays were conducted to determine female potato leafhopper ovipositional preference on alfalfa grown in potting soil with or liquid dairy manure treatment. Nymph emergence was counted as a proxy for ovipositional preference and no significant differences were detected. The results we observed are inconclusive with regards to the goal of this study. Explanations for inconsistent results between 2011 and 2012 and the laboratory assays are explored. Future work could explore effects on potato leafhoppers due to differences in the microbial communities of the soil and manures.

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Chasen E.M., Dietrich C.H., Backus E.A., Cullen E.M. (2014). Potato leafhopper (Hemiptera: Cicadellidae) ecology and integrated pest management focused on alfalfa. Accepted 01/24/14: Journal of Integrated Pest Management.
  • Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Chasen, E.M. 2014. Integrated pest management for the potato leafhopper (Empoasca fabae) in alfalfa. Ph.D. Dissertation, University of Wisconsin-Madison, Madison, WI.


Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: The present study examines the effects of host plant resistance and orchardgrass intercrop on potato leafhopper (PLH) populations in alfalfa, as well as yield and forage quality response to PLH and the respective cropping systems. Multi-year research experiments are ongoing at two locations: one at Arlington, WI Agricultural Research Station (AARS) and two at the US Dairy Forage and Research Center (DFRC) Prairie du Sac, WI. Experiments are arranged in complete randomized block with a 2 x 2 factorial design. Factorial treatments are alfalfa variety (PLH-susceptible and PLH- resistant) and orchard grass intercrop (alfalfa intercropped with grass and direct seeded alfalfa). RESULTS (for PLH Response): Host plant resistance suppressed PLH populations at different sampling points over the 5-site years to date, but most notably at peak leafhopper abundance time points in the seeding years. The effect of orchardgrass intercropped with alfalfa on potato leafhoppers was minimal. In the seeding years, there was no significant effect of orchard-grass at any sampling point. In production years, the effect of grass varied between locations. At AARS, orchardgrass suppressed PLH at three time points: July 12, 2011 (p=0.0013), May 22, 2012 (p=0.0062) and May 30, 2012 (p=0.00162). Suppression effect ranged from 10-80% between the three sampling dates, but PLH densities were below economic threshold. Orchardgrass in the fall seeding at DFRC had a significant effect on PLH on May 30 (p=0.0123) and June 6 (p=0.0206) at which points PLH were more abundant in plots with grass. Orchardgrass presence and host plant resistance did not have a significant interaction. SUMMARY 1: (1) Potato leafhoppers only had an impact on yield when established economic threshold populations were reached (i.e., our current data do not support lowering the PLH economic threshold, (2) Resistant alfalfa significantly suppressed potato leafhopper in the seeding year even when pest pressure was low. (3) The effect of orchardgrass intercropped with alfalfa on potato leafhoppers was minimal. An additional set of field and greenhouse experiments are underway to investigate putative relationship between soil/plant fertility treatments and PLH response. In the summers of 2011 and 2012 at AARS, PLH response to liquid dairy manure application as well as mineral N-P-K-S application and a control treatment with no soil amendment was studied. In 2011, we saw that when PLH populations peaked, manure did suppress potato leafhopper populations. In 2012, we repeated the experiment in two fields at AARS. Results from one field show an increase in potato leafhopper abundance in manure plots, and no difference between treatments when populations reached peak abundance. Results from the other field show no significant difference between treatments at any point. Complementary choice test experiments (oviposition and emerged nymph counts) in the greenhouse (PLH exposed to manured and non-manured potted alfalfa plant clones of a susceptible variety) showed no suppressive effect of manure on PLH oviposition choice. PARTICIPANTS: INDIVIDUALS: EILEEN M. CULLEN, Associate Professor/Extension Specialist, University of Wisconsin-Madison Entomology Department, Project Director and thesis advisor and mentor to Elissa Chasen, PhD graduate student on this project. Roles: Project coordination and responsibility, experimental research design and oversight on entomological research component, generate, analyze, publish and disseminate results through research/extension field and forage crops entomology IPM program. DANIEL UNDERSANDER, Professor/Extension Specialist, UW-Madison Agronomy Department, KEN RAFFA and DAVID HOGG, Professors, UW-Madison Entomology Department, and CARRIE LABOSKI, Associate Professor/Extension Specialist, UW-Madison Soil Science Department, and MARK SMITH, Pioneer Hibred International alfalfa breeding station, Arlington, WI. Roles: Serving on Elissa Chasen's PhD thesis committee and consulting on field and/or greenhouse experiment aspects. TRAINING OR PROFESSIONAL DEVELOPMENT: ELISSA CHASEN, PhD Graduate Student Research Assistant, University of Wisconsin-Madison Entomology Department. Role: Conduct entomology and soil science field and laboratory experiments, data analysis, and co-author publications resulting from this project. TARGET AUDIENCES: Target audiences include Wisconsin, Upper Midwest and U.S. forage hay producers, Extension educators and county agricultural agents, IPM researchers at land-grant universities and colleges, certified crop advisors and agribusiness professionals who serve or interact with field and forage crop growers managing potato leafhopper, insecticide treatment timing, and non-target effects of insecticide applications on field and forage cropping system pest and beneficial insects. Efforts to reach target audiences include extension and outreach field day presentations, Extension entomology newsletters, and on-farm demonstration networks as the project develops. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Results from the first three years of the project were presented by PhD graduate student Elissa Chasen as a 20 minute oral presentation talk at the 2013 Wisconsin Crop Management Conference, Madison, WI. Approximately 300 direct contact audience members gained knowledge of our findings on PLH integrated pest management at this event (crop consultants, farmers, extension agents, peer researchers). Ms. Chasen will be presenting a poster on the nutrient trial aspect of this project (PLH response in field and greenhouse to dairy manure and/or mineral fertilizers) at the Feb. 2013 Midwest Organic Sustainable Education Service Organic Farming Conference, LaCrosse, WI (poster abstract accepted Jan. 2013). Results from this project will allow us to provide recommendations to conventional and organic farmers for incorporating host plant resistance, intercropping, insecticide use (as appropriate to production system), and/or soil nutrient management practices into PLH treatment decisions.

Publications

  • Chasen, E., E. Cullen and D. Undersander. 2013. Integrated management of the potato leafhopper in alfalfa. Page 91 to 100 in Proc. Wisconsin Crop Management Conference, Madison, WI.


Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: A multi-year (2010 to 2013) field experiment (IPM System Trial) was continued at University of Wisconsin Arlington Agricultural Research Station examining potato leafhopper, PLH, (Empoasca fabae) response to susceptible and resistant alfalfa (Medicago sativa) varieties, grown with and without an orchard grass (Dactylis glomerata) intercrop. Objectives of this IPM System Trial are to 1) determine if combinations of PLH chemical and host plant resistance control tactics can result in a decreased need for chemical control; and 2) evaluate whether chemical control of PLH at low densities is warranted for current alfalfa varieties at high alfalfa market values. Design: Randomized Complete Block Design, eight replications, 2 x 2 factorial whole plot (25.9 m x 6.7 m) treatments consisting of Alfalfa variety (resistant Pioneer 53H92 or susceptible Pioneer 55V48), and Orchardgrass (Profit variety) intercrop (yes or no). Three split plot (6.7 m x 8.6 m) insecticide treatments of pyrethroid insecticide (active ingredient lambda-cyhalothrin) applied at 230 ml/ha (3.2 oz/acre) as untreated control, economic threshold, and half the current economic threshold were used to create a range of potato leafhopper densities to determine alfalfa yield response to potato leafhopper. Data Collection: Weekly PLH counts determined from 20 pendulum sweeps; Yields taken with a sicklebar harvester through the center of each plot. Weights taken at harvest along with percent dry matter of samples are used to calculate kg/ha (tons/acre). Analysis: PLH response values accumulated between harvest dates (total PLH collected in the sweep net summed for each sample week). PLH - alfalfa yield response was determined through linear models and ANOVA for the subset of data in which insecticides are not sprayed. 2011 Results Summary: Glandular haired PLH-resistant alfalfa variety consistently suppressed PLH, but in 2011, this resistance conferred a yield drag due to low PLH pressure. Grass intercrop did not significantly suppress PLH in any of the plots in 2011. Fall 2011 and spring 2012 seeding experiments at USDA Dairy Forage Research Center in Prairie du Sac, WI have been/will be implemented to increase probability of achieving desired PLH pressure in alfalfa plots for remainder of IPM System Trial. Additionally, starting in 2012 season, caged plant method will be implemented in the field as per Lefko et al. 2000 (Agron. J. 92:726-732) to ensure yield response linear regression data and coefficients required to calculate PLH economic injury level and economic threshold from IPM System Trial field data, 2012 and 2013. In a separate, concurrent field study at Arlington station we are examining PLH response to liquid dairy manure amendment to alfalfa immediately following first and second cutting at application rate of 5,000 gal/ac. A PLH colony was established and greenhouse companion experiment is underway as a complement to study soil and plant nutrient effects on PLH response as another factor contributing toward an IPM systems approach for PLH in Midwestern U.S. alfalfa production. PARTICIPANTS: INDIVIDUALS: EILEEN M. CULLEN, Associate Professor/Extension Specialist, University of Wisconsin-Madison Entomology Department, Project Director and thesis advisor and mentor to Elissa Chasen, PhD graduate student on this project. Roles: Project coordination and responsibility, experimental research design and oversight on entomological research component, generate, analyze, publish and disseminate results through research/extension field and forage crops entomology IPM program. DANIEL UNDERSANDER, Professor/Extension Specialist, UW-Madison Agronomy Department, KEN RAFFA and DAVID HOGG, Professors, UW-Madison Entomology Department, and CARRIE LABOSKI, Associate Professor/Extension Specialist, UW-Madison Soil Science Department, and MARK SMITH, Pioneer Hibred International alfalfa breeding station, Arlington, WI. Roles: Serving on Elissa Chasen's PhD thesis committee and consulting on field and/or greenhouse experiment aspects. TRAINING OR PROFESSIONAL DEVELOPMENT: ELISSA CHASEN, PhD Graduate Student Research Assistant, University of Wisconsin-Madison Entomology Department. Role: Conduct entomology and soil science field and laboratory experiments, data analysis, and co-author publications resulting from this project. TARGET AUDIENCES: Target audiences include Wisconsin, Upper Midwest and U.S. forage hay producers, Extension educators and county agricultural agents, IPM researchers at land-grant universities and colleges, certified crop advisors and agribusiness professionals who serve or interact with field and forage crop growers managing potato leafhopper, insecticide treatment timing, and non-target effects of insecticide applications on field and forage cropping system pest and beneficial insects. Efforts to reach target audiences include extension and outreach field day presentations, Extension entomology newsletters, and on-farm demonstration networks as the project develops. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
CHANGE IN KNOWLEDGE: Results from the first two years of the PLH IPM System Trial were presented by PhD graduate student on the project, Elissa Chasen, as a poster display at the 2011 Entomological Society of America meeting in Reno, Nevada, November 2011. Approximately 50 direct contacts and additional indirect contacts in the field of economic entomology and extension education increased their knowledge and awareness of potato leafhopper IPM through this poster presentation and abstract publication by becoming aware of this project and preliminary results to broaden the context of potato leafhopper IPM. Results from this work will allow us to provide recommendations for incorporating host plant resistance, intercropping, and/or soil nutrient management practices into a potato leafhopper insecticide treatment decision.

Publications

  • No publications reported this period


Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: The goal of this project is to determine an integrated pest management (IPM) system for alfalfa that most effectively suppresses the potato leafhopper (PLH), such that insecticide use may be reduced without incurring yield or forage quality loss. Proactive IPM management systems are being tested in large plot multi-year study sites at Arlington and Lancaster UW Agricultural Research Stations in a randomized complete block factorial design with split plots. First, we are determining the effect of glandular-haired host plant resistance on PLH populations by planting a PLH-susceptible and a PLH-resistant alfalfa variety. Second, we are intercropping orchard grass with alfalfa to determine how PLH populations are impacted (PLH emigration hypothesis). Imposed upon whole plots are three levels of insecticide application timing: current PLH economic threshold, half of the current threshold, and unsprayed control. PLH are sampled weekly at each study site June - September to determine PLH population response to whole plot X insecticide timing subplot treatment combinations. Yield and forage quality data are collected and assessed for each plot at each cutting. The Arlington IPM Trial site was seeded 4 May 2010. PLH sampling and yield and forage quality data were collected during the seeding year for 2nd, 3rd and 4th crops. Site selection, soil test analysis, and plot marking took place at Lancaster Fall 2010. The experiment will be spring seeded April 2011. Additionally, we are investigating putative plant defense mechanism(s) via soil fertility with application of liquid dairy manure after first and second cuttings in an established stand (first production year after seeding year). A separate small plot nutrient trial field experiment is located on a second year alfalfa stand at Arlington in each year of the project. Treatments consist of a control, liquid dairy manure application, and N-P-K + S fertilizer calibrated to the liquid dairy manure sample for these same nutrients. Treatments are replicated six times in a randomized complete block design. The first nutrient trial was completed at Arlington during the 2010 growing season. In 2011, the trial will be moved to a new location, again a second year stand to which fertility treatments will be applied immediately following 2nd and 3rd cuttings. A corresponding greenhouse experiment will detect and clarify mechanism(s) of increased alfalfa plant defense to PLH through manure input soil fertility treatment. Eileen Cullen (PI) mentored Elissa Chasen (PhD graduate student on project), meeting weekly during the academic year and every other week during the growing season, plus field site visits. Chasen completed Spring and Fall 2010 semester coursework adding a soil science minor to her entomology major, formed her PhD advisory committee with representation from Entomology, Soil Science and Agronomy departments, and drafted her PhD thesis proposal (successfully presented and approved at February 2011 PhD Certification Meeting). PARTICIPANTS: INDIVIDUALS: EILEEN M. CULLEN, Associate Professor/Extension Specialist, University of Wisconsin-Madison Entomology Department, Project Director and thesis advisor and mentor to Elissa Chasen, PhD graduate student on this project. Roles: Project coordination and responsibility, experimental research design and oversight on entomological research component, generate, analyze, publish and disseminate results through research/extension field and forage crops entomology IPM program. DANIEL UNDERSANDER, Professor/Extension Specialist, UW-Madison Agronomy Department, KEN RAFFA and DAVID HOGG, Professors, UW-Madison Entomology Department, and CARRIE LABOSKI, Associate Professor/Extension Specialist, UW-Madison Soil Science Department. Roles: Serving on Elissa Chasen's PhD thesis committee and consulting on field and greenhouse experiment aspects. TRAINING OR PROFESSIONAL DEVELOPMENT: ELISSA CHASEN, PhD Graduate Student Research Assistant, University of Wisconsin-Madison Entomology Department. Role: Conduct entomology and soil science field and laboratory experiments, data analysis, and co-author publications resulting from this project. TARGET AUDIENCES: Target audiences include Wisconsin, Upper Midwest and U.S. forage hay producers, Extension educators and county agricultural agents, IPM researchers at land-grant universities and colleges, certified crop advisors and agribusiness professionals who serve or interact with field and forage crop growers managing potato leafhopper, insecticide treatment timing, and non-target effects of insecticide applications on field and forage cropping system pest and beneficial insects. Efforts to reach target audiences include extension and outreach field day presentations, Extension entomology newsletters, and on-farm demonstration networks as the project develops. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
May-September 2010 marked the first field season of data collection for this research project at the Arlington Agricultural Research Station IPM Trial study site. For the current project report period January 1 to December 31, 2010, year one of this four-year project, there are no outcomes/impacts to report.

Publications

  • No publications reported this period


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: This project started October 1, 2009. Previously, during summer 2009, a PhD Entomology graduate student (Elissa Chasen) was recruited to the project under supervision of major professor, PI: Cullen. During the first 3 months of the project (October 1 - December 31, 2009), Chasen undertook coursework and began literature review to prepare for writing her thesis proposal in 2010. Field work will commence for this project spring 2010 with spring seeding of alfalfa plots for potato leafhopper economic threshold research at Lancaster and Arlington Agricultural Research Stations. In preparation for forthcoming laboratory experiments with alfalfa pest insect biological control agents (alfalfa weevil and alfalfa blotch leaf miner parasitoids), Cullen prepared a greenhouse laboratory space with a Potter Spray Tower to be used for this project, likely during fall 2010. Cullen initiated contact with UW Extension county agriculture agents who are interested in hosting on-farm research demonstration sites for potato leafhopper IPM research during this project. PhD student, Chasen, will incorporate an extension outreach component to her PhD thesis under this Hatch project in partnership with UW Extension county agents. PARTICIPANTS: INDIVIDUALS: EILEEN M. CULLEN, Associate Professor/Extension Specialist, University of Wisconsin-Madison Entomology Dept., Project Director. Roles: Project coordination and responsibility, experimental research design and oversight on entomological research component, generate, analyze, publish and disseminate results through research/Extension field crops IPM program. TRAINING OR PROFESSIONAL DEVELOPMENT: ELISSA CHASEN, PhD Graduate Student Research Assistant, University of Wisconsin-Madison Entomology Dept. Role: Conduct entomology and field and laboratory experiments, data analysis, and co-author publications resulting from this project. TARGET AUDIENCES: Target audiences include Wisconsin, Upper Midwest, and U.S. forage hay producers, Extension educators and county agents, IPM researchers at land-grant universities and colleges, certified crop advisors and agribusiness professionals who serve or interact with field and forage crop growers dealing with the potato leafhopper pest issue, insecticide treatment timing, and non-target effects of insecticide application on alfalfa insect pest natural enemies. Efforts to reach target audiences are to include extension and outreach field day presentations, Extension entomology newsletters, and on-farm demonstration networks as the project develops. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Because this project started October 1, 2010, (3 months prior to first report due date), there are no outcomes/impacts to report at this early stage. The first field research season will commence at spring 2010 alfalfa research plot seeding (Lancaster and Arlington Agricultural Research Stations), and on-farm demonstration sites with UW Extension county agricultural agents.

Publications

  • No publications reported this period