Pecan Hedge-pruning: A Sustainable Management Option for the Southeastern US

Progress report for LS20-340

Project Type: Research and Education
Funds awarded in 2020: $299,894.00
Projected End Date: 03/31/2023
Grant Recipients: University of Georgia; USDA-Agricultural Research Service
Region: Southern
State: Georgia
Principal Investigator:
Dr. Jason Schmidt
University of Georgia
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Project Information

Abstract:

Hedge-pruning of pecan (Carya illinoinensis) trees is a cultural management strategy that has been shown to mitigate effects of tree shading, reduce alternate bearing tendencies, improve tree health and increase orchard profitability. It has been practiced successfully in high-light environments and has become the standard method employed in the arid regions of the southwestern US. Environmental conditions in the southeastern US differ greatly from regions where hedging has been implemented (e.g., in terms of cloud cover and atmospheric water vapor). Thus, it is unclear whether hedge-pruning will be beneficial and sustainable in the Southeast, which is the major pecan-producing region in the US. Research is urgently needed to determine applicability and best management practices for hedge-pruning in the Southeast. Initial studies showed promise for hedge-pruning in the southeastern US. For example, in Georgia, winter hedge-pruned trees had reduced water stress compared to non-hedged trees, and nut weight and percent kernel were increased by hedge-pruning trees in the winter. Hedge-pruned trees also suffered less storm-related injury. Hedge-pruning has a positive impact on the management of scab, the most destructive disease of pecans in the southeastern US. Scab was easier to manage by bringing the nut crop within reach of efficacious spray coverage. Although preliminary studies of arthropod pest populations in hedged-pruned and non-hedged trees showed little difference between treatments implying that hedge-pruning does not increase pest pressure, there were indications that hedge-pruned trees had reduced injury from black pecan aphids, Melanocallis caryaefoliae, a major insect pest in pecans, and had increased aphid parasitism early in the season.

In recent years in the Southeast, hedge-pruning pecan has gained popularity among growers. Therefore, research is warranted to determine the ecological and economic sustainability of hedge-pruning in the southeastern region. In fact, pecan hedge-pruning is listed as a major research priority identified by the Georgia Pecan Growers Association. There are unknown ramifications of hedge-pruning that must be addressed. Specifically, the impact of hedge-pruning younger trees versus older trees is unknown, and the effect of timing of hedge-pruning (summer versus winter) on the tree, and impact on critical pests and diseases is preliminary. In relation to these aspects, we propose assessing critical horticultural parameters (nut yield, quality, water-use efficiency, and nutrition), disease (incidence and severity of scab, colonization of branches by wood rot fungi), insect pest and natural enemy populations and pest-related injuries. Moreover, hedge-pruning trees may result in changes in the quantity of radiant penetration to the understory, impact soil moisture and affect the biotic community. Thus, we will evaluate impacts of hedge-pruning on soil-borne entomopathogens that provide biocontrol services against soil inhabiting pecan pests including pecan weevil, Curculio caryae. There will be a comprehensive economic analysis and implementation of Extension and Outreach programs based on the research results. Findings from these studies will be beneficial to other orchard and tree nut production systems where hedged-pruning is practiced.

Project Objectives:

Our main goal is to evaluate the sustainability of hedge-pruning pecan trees in the southeastern US. Prior research demonstrated that hedge-pruning can have positive impacts on some horticultural parameters, and can improve disease and insect management. However, the relative benefits of hedge-pruning trees of different ages, or hedge-pruning trees at certain times of the year is not known. We propose the following objectives:

1) Determine relative impacts of hedge-pruning young and older trees by comparing horticultural and production variables, disease and insect pest prevalence, and natural enemy populations in hedged-pruned and nonhedged young and older pecan trees.

2) Define the effects of timing (summer versus winter) of hedge-pruning of pecans on the variables listed in objective 1.

3) Perform an economic feasibility assessment of hedge-pruning pecan based on the results obtained from objectives 1 and 2.

4) Share the results with growers and other stakeholders via diverse Extension and outreach programs.

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Dr. Tim Brenneman (Researcher)
  • Brent Brinkley - Technical Advisor
  • Jason Brock - Technical Advisor (Educator)
  • Jason Brock - Technical Advisor (Educator)
  • Dr. Ted Cottrell (Researcher)
  • Mike Jaros - Producer
  • Danny Levie - Producer
  • Buck Paulk - Producer

Research

Materials and methods:

The studies proposed here will be conducted at the following locations:

            Experiment Site 1: Marshallville, GA where ~25-yr old hedge-pruned trees will be compared with non-hedged trees. Please refer to Fig. 7 for more details on the site and hedge-pruning program. The trees were hedge-pruned on alternate sides since 2013, and due to the relatively young age the tree height is still comparable between hedge-pruned and nonhedged trees (~35 ft); but overall tree canopy volume and row interference is contrasts (Fig 8).

            Experiment Site 2: Montezuma, GA where ~40-yr old hedged-pruned will be compared with non-hedged trees. Please refer to Fig. 9 for more details on the site and hedge-pruning program. Older trees were hedge-pruned on the sides and top, thus hedge-pruned trees are considerably shorter (~40ft) when compared to the nonhedged trees (~60ft).

            Experimental Site 3: Ray City, GA where ~30-yr old summer hedge-pruned trees will be compared with winter hedge-pruned trees. Please see Fig. 10 for more details on the site and the hedge-pruning program.

            All trees in the experiments (hedged and non-hedged) will be receiving the standard grower management including irrigation, spray inputs, fertilizer, etc.

            Across all comparisons, treatment blocks are replicated accordingly at each site. Data will be analyzed using standard statistical methods including, but not limited to analysis of variance and regression analysis (Steel and Torrie 1980, Cochran and Cox 1957).

            The following are the variables that will be collected, obtained and analyzed from the trees in orchards comparing the different hedge-pruning treatments as described above.

  1. Assessment of production (nut quality and size), water and nutritional status. Methods to be followed will be based on that of Wells (2018). Midday stem water potential will be determined using a pump-up pressure chamber (PMS Instruments, Albany, OR) by measuring the water potential of leaflets located near the trunk or a main scaffold branch at mid-day. Soil moisture will be measured with a Field Scout TDR 300 Soil Moisture Meter (Spectrum Technologies, Aurora, IL) at 20 cm depth within the wetted zone of irrigation on each sampling date at the same time that stem water potential is measured for each tree. All plots will be mechanically harvested separately. In-shell nuts will be dried to 4.5% moisture with a commercial drier and processed in a commercial cleaning plant to remove all sticks, leaves, and debris. All cleaned nuts will be weighed by plot to obtain in-shell nut yield for each plot. A 50-nut sample will be obtained from each plot at harvest to determine nut size and quality (percent kernel). The effects of hedge-pruning on nutritional status of dormant and summer hedge pruned trees will be assessed through leaf and soil sampling of each plot. Samples of 50 pairs of leaflets will be collected randomly throughout each plot and analyzed for all macro and micro-nutrients. Temperature, light intensity and relative humidity in tree canopy will also be recorded. Cooperators: Wells, Jaros, Levi, Paulk
  2. Assessment of incidence and severity of disease.

            2a. Assessing scab in trees. Methodologies will be the same in all experiments. Samples will be collected at up to four heights (in hedge-pruned trees only 3 heights). Ten compound leaves, fruit (mid and late season samples) and shoots (only late season) will be collected at each height on both row-sides of each sample tree using a hydraulic lift at approximately 5, 8, and 11 and 14+ m. Heights above ground will be measured using a laser rangefinder at the time of sample collection. Leaf and fruit samples will be assessed for severity of scab based on the percent area diseased by visual estimation on each leaflet and on each of the four valve faces. Assessments will be aided by previously developed standard area diagrams for leaflets and fruit. At the end of the season, the length of a sample of 10 shoots from each height in each tree will be measured and the number of scab lesions counted (scab lesions on shoots are considered a potential important source of inoculum for the following season’s epidemic). Methodology will be based on Bock et al 2017.

            2b. Assessing tree limb colonization by wood rot fungi. Trees in orchards at the Marshallville site which has been hedge-pruned since 2013 will be monitored for wood rot fungi. A total of 100 trees (50 hedge-pruned and 50 non-pruned) will be surveyed annually to determine incidence of wood rot colonization by visually assessing all limbs in the trees for evidence of fruiting bodies of common fungi (including but not limited to Trametes versicolor and Schizophyllum commune). Species identification will be based on morphology and, if available for the fungus, PCR diagnosis (Chen et al., 2015).

Cooperators: Bock, Jaros, Levi, Paulk

  1. Assessment of insect pest populations, insect-related injury and beneficial insect populations.

            3a. Monitoring of insect pest populations and insect-related nut injuries. Across all studies, standard monitoring approaches for scouting pecan insect pests will be followed (Grantham et al 2002, Reid 2002). We will sample leaves for live aphids, parasitized aphids and mites at three distinct periods in the crop phenology coinciding with the grower management programs for these pests: post-pollination (mid-May), rapid nut sizing stage (July) and kernel filling stage (late August). A minimum of 100 leaf samples will be taken from the lower and upper canopies of trees for each treatment in each experiment at each sampling date. Leaf samples will be placed in Ziploc bags upon collection, and placed in coolers during transport to the lab where they will be examined for the target pests under the microscope.

            Periodic collection of nut samples to assess for insect-related injury will be conducted in late May for pecan nut casebearer injury, in late June for shuckworm and nut curculio infestation, and at harvest for pecan weevil, shuckworm and stinkbug attacks. Samples will be taken from the lower and upper sections of the trees, placed in Ziploc bags and will be taken to the lab for examination. A minimum of 100 nut samples will be collected from each treatment in each experimental site per sampling date.

            3b. Investigation of the natural enemy populations. We will be deploying yellow sticky cards in the lower and upper canopy of trees for one week during distinct periods in the season: post-pollination, rapid nut sizing and kernel filling stages. A minimum of 10 yellow sticky cards will be deployed per treatment at each experimental site per trapping period. We decided to use yellow sticky cards as these were proven to be effective in monitoring for pecan aphid parasitoid, Aphelinus perpallidus (Fig. 10). The parasitized aphids collected during the leaf sampling, as described above, will be separated and reared until parasitoid emergence for assessment of parasitism rates. Another sampling methodology (e.g., using small pyramid traps deployed in the lower and upper canopy of trees for a week) may be explored to survey other generalist predators such as coccinellids and spiders (Paulsen et al 2011, Fig. 10).

Cooperators: Acebes, Schmidt, Jaros, Levi, Paulk

  1. Assessment of belowground entomopathogens. Methods to determine persistence of entomopathogens will be based on those described by Shapiro-Ilan et al. (2003, 2017b). Six soil cores will be taken 1 meter from the trunk and another six cores will be taken from the 1 m distance from the trunk to just inside the dripline (approximately 3 meters) of a hedge-pruned and nonhedged pecan tree. It is important that the longer distance remain inside the herbicide strip (not into the grass beyond the strip). Samples will be pooled from within each distance (so each tree has three pooled samples, one from each distance). Soil will be brought back to the lab (in a cooler) and will be exposed to bait insects (greater wax moth, Galleria mellonella). Koch’s postulates will be conducted to verify the presence of entomopathogenic nematodes and fungi. Identification of entomopathogens will be conducted by Shapiro-Ilan and if additional verification is needed by the USDA-ARS collection curators (Shapiro-Ilan holds an International Collection of entomopathogenic nematodes and is versed in identification of entomopathogenic fungi as well). Mortality in bait insects due to entomopathogenic fungi nematodes and overall mortality will be compared among treatments using standard statistical approaches (Steel and Torrie 1980). Samples will be taken bi-weekly during April to October. Cooperators: Shapiro-Ilan, Jaros, Levi, Paulk
  2. Economic analysis, Extension and Outreach.

            5a. Economic analysis. In conjunction with the various field trials, an economic analysis will be conducted to assess the economic costs and benefits of pecan hedge-pruning strategies relative to non-hedged orchards and the timing of when hedge-pruning is conducted. This is a critical component not only to evaluate the efficacy of pecan hedge-pruning, but to also deliver clear recommendations to growers as part of the larger extension and outreach program, and help guide future orchard-level research on pecan hedge-pruning. The economic analysis will synthesize the findings of the various orchard trials with input and output price data. Using standard statistical and extension budging methods, estimates of the relative profitability of hedge-pruning vs. nonhedging and summer vs. dormant hedge-pruning will be evaluated by incorporating the orchard trial results on tree health (e.g. disease and pest rates), production measures (e.g., nut size, yield, and quality), input costs (e.g., labor rates, equipment, water usage), and market price data into a grower-level economic analysis and enterprise budget. Further, sensitivity analysis including multivariate econometric modeling, inclusion of temporal considerations, and production practice transition costs (Lima et al., 2013) will be conducted.

            Overall, the economic feasibility assessment and sensitivity analysis will yield estimates (with confidence intervals) of the expected costs and benefits of pecan hedge-pruning relative to not hedging. However, as revealed in previous research, non-monetary considerations such as grower risk perceptions, subjective beliefs of new production practices, and information and experience have been found to influence risk management and technology adoption decisions (Menapace, Colson, and Raffaelli, 2013; 2015). Hence, to complement the economic analysis and aid in the development and refinement of the extension and outreach materials and programs, grower surveys will be administered to assess grower perceptions and knowledge of hedging strategies for pecans. The surveys will be administered in conjunction with the planned extension and outreach grower meetings and field days. 

            5b. Extension and Outreach Programs. Extension and Outreach programs will be conducted including demonstration trials, grower, industry and scientific meetings. Results will be published via print (magazines, spray guides, fact sheets) and online resources (blogs, apps, websites). Please see the detailed description of our Extension and Outreach programs in the “Information Dissemination and Outreach Plan” section. Drs. Acebes, Schmidt, Hudson and Wells have Extension responsibilities in the southeastern US.

Cooperators: Colson, Acebes, Schmidt, Hudson, Shapiro-Ilan, Bock and Wells

Research results and discussion:

2021 First Year Report Pecan Hedging (LS20-340)

Despite the limitations posed by COVID-19, the research team was able to accomplish several objectives outlined in the proposal. The results summary and discussion are outlined per study area for simplicity.

Horticulture

There was no statistical difference in yield between hedged and non-hedged trees in 2019; however, in 2020 non-hedged trees produced a higher (P<0.05) yield than hedged trees. Nut size (as reflected in a lower number of nuts per lb) was greater (P<0.05) in hedged than non-hedged trees during both years of the study. In 2019 leaf potassium (K) was higher (P<0.05) in non-hedged than in hedged trees. Hedged trees had higher (P<0.05) leaf nitrogen (N) concentration in 2020 than non-hedged trees.

There was no difference between summer hedged and dormant hedged trees with respect to yield.

The timing of hedging influenced leaf nutrient concentration in 2019 but not in 2020. Leaf N was higher in summer hedged trees than in dormant hedged trees in 2019. Summer hedged trees had lower (P<0.05) leaf K and leaf zinc (Zn) concentrations in 2019 than did dormant hedged trees.

Hedged vs Non-Hedged Yield of ‘Desirable’ Pecan in 2019 and 2020

2019 Summer vs Dormant Hedging Yields

2020 Summer vs Dormant Hedging Yield

2019 Summer vs Dormant Nuts/lb

2020 Summer vs Dormant Nuts/lb

2019 Summer vs Dormant Percent Kernel

2020 Summer vs Dormant Percent Kernel

Leaf Nutrient Concentration of Hedged and Non-Hedged 'Desirable' Pecan Trees in 2019 and 2020

Year Treatment N P K Zn
2019 Hedged 3.13a 0.12a 1.13a 90a
  Non-Hedged 2.94a 0.11a 1.27b 85a
           
2020 Hedged 2.91a 0.12a 1.05a 73a
  Non-Hedged 2.76b 0.12a 1.11a 83a

Leaf Nutrient Concentration of Summer and Dormant Hedged 'Creek' and 'Caddo' Pecan Trees During 2019

Treatment N P K Zn
Time of Hedging        
Summer 3.2a .016a 0.92b 77b
Dormant 2.9b 0.15a 1.07a 83a
Cultivar        
Creek 3.09a 0.15a 0.97b 79a
Caddo 3.03a 0.15a 1.02a 81a
P Value        
Hedging Time <0.001 0.30 <0.001 0.01
Cultivar 0.21 0.51 0.05 0.32
HT X Ctvr 0.47 0.63 0.83 0.004

Leaf Nutrient Concentration of Summer and Dormant Hedged 'Creek' and 'Caddo' Pecan Trees During 2020

Treatment N P K Zn
Time of Hedging        
Summer 2.98a 0.16a 1.05a 80a
Dormant 2.93a 0.15b 1.00a 76a
Cultivar        
Creek 2.92a 0.15a 1.03a 86a
Caddo 2.99a 0.15a 1.02a 70a
P Value        
Hedging Time 0.49 0.009 0.27 0.71

Second Year Report

During the 2021 period, we are still exhibiting limitations of working in the lab, primarily on the USDA side of our team, but despite this, we were able to carry out an extensive amount of field research, and are still actively finalizing the processing of samples taken in preparation for extension and research outputs. Below we summarize efforts by each project team member. One challenge we experienced with our project sites was that one grower thinned the orchard and so the treatments were a mixture of thinned and hedged. We will likely not be able to use that data for advancing our understanding of hedging effects, but later we will use these data combined with other sites to provide a general overall characterization of natural enemy and pest populations in southeast pecan systems.

  1. Plant Pathology (Clive Bock, USDA)

Determine relative impacts of hedge-pruning young and older trees by comparing disease in hedged-pruned and non-pruned young and older pecan trees. Define the effects of timing (summer versus winter) on hedge-pruning of pecans. Experiments were at four locations with hedge-pruning treatments as follows:

  1. Ray City (summer and winter hedge-pruning – all fungicide treated)
  2. Marshallville (hedge-pruned and non-hedge-pruned trees – all fungicide treated)
  3. Montezuma (hedge-pruned and non-hedge-pruned trees – all fungicide treated)
  4. Byron (hedge-pruned and non-hedge-pruned trees – fungicide treated and mon-treated trees)

At all locations, scab assessments were made on leaves and fruit at two points during the season - the first sample was taken when fruit were immature (late June/early July), and the second sample when fruit were mature from mid-August to mid-September. Scab assessments were also taken on the shoots in January of 2022. Depending on the experiment, samples were collected at up to 4 heights. Ten compound leaves and ten fruit were collected at each height on both row-sides of each sample tree. Samples were collected using a hydraulic with sample heights measured using an Opti-Logic Laser Rangefinder (Opti-Logic, Tullahoma, TN). Leaf samples were assessed for severity of pecan scab based on the percent area diseased was visually estimated on each leaflet of each compound leaf. Scab on fruit was assessed similarly - pecan fruit are comprised of four valves joined along their edges by a suture, and each of the four valve faces was assessed individually for severity of pecan scab based on the percent area diseased. Assessments were aided by standard area diagrams for scab severity on both leaves and for fruit. Fruit fresh weight was determined individually at the time. Shoots were measured and the number of scab lesions counted for each shoot. Data will be analyzed using a generalized linear mixed model with fixed effects of treatment, tree height and tree side, and random effects of replicate.  

  1. Entomology (Angel Acebes-Doria and Jason Schmidt, UGA)

Determine relative impacts of hedge-pruning young and older trees by comparing horticultural and production variables, disease and insect pest prevalence, and natural enemy populations in hedged-pruned and non-pruned young and older pecan trees. I the second year of the project we collected pest, natural enemy, and leaf samples from trees under the different management strategies. Currently we are working through the samples. We brought on a PhD student in early 2021, and he began processing the samples from the 2020 season, and then with our total team mobilized for collecting, the MS student (Kate Phillips) and PhD student (Pedro Toledo), along with undergraduate research assistants, collected the data. We have currently finished counting insects from sticky cards, and leaf samples, and have presented the work. In addition, our team is working on a manuscript. During sampling, we also took suction samples of the pecan canopy to better characterize less mobile predators in the canopy, and to assess parasitism rates on aphids (i.e. ratio of aphid mummies/aphids). Our sorting of samples so far has provided over 2000 individuals, and we are still working through the samples.

  1. Entomopathogen (David Shapiro-Ilan, USDA)

During the second year of the project, we again collected soil samples in hedged vs. non-hedged trees to assess impact on entomopathogen. This was conducted at the Byron location. As in previous years, primarily entomopathogenic fungi were observed but also some entomopathogenic nematodes. The overall effect showed significantly higher entomopathogen populations (based on insect baiting) in the hedged treatments relative to non-hedged. These data are currently being analyzed and prepared for publication.

 

Participation Summary
3 Farmers participating in research

Education

Educational approach:

Economics

Economics Component - Activities – Year 1

  • In collaboration with the project team, a survey instrument was developed and administered to southeastern US pecan growers to obtain estimates and insights on the:
    • Prevalence of hedge-pruning as a management strategy for pecan trees.
    • Perceived (or realized) positive and negative impacts of hedge-pruning on crop production and profitability.
    • Potential barriers and drivers of adoption of hedge-pruning by pecan growers.
    • Research and outreach support that would facilitate pecan growers’ assessment of the suitableness of hedge-pruning for their operation.

Economics Component – Brief Summary of Findings – Year 1

  • A significant majority of pecan growers perceive positive impacts of hedge-pruning resulting in improved revenues for their operation including:
    • Improved nut quality (93% of growers agree) and nut yield (69% growers agree).
    • Reduced pest pressures and improve spray coverage.
    • Lower risk of wind damage.
  • Cost and insufficient evidence of effectiveness and profitability are the most significant barriers to adoption of hedge-pruning by growers.
    • 72% of growers perceive the cost of hedge-pruning to be expensive.
    • Slightly less than half of growers thought the improvement in revenue would outweigh the cost, with 12% of growers stating that hedge-pruning would reduce farm profits.
    • Many growers stated that to evaluate whether to adopt, they need more evidence on (i) the effectiveness of hedge-pruning on operations similar to their own and (ii) the economic returns from the practice.
  • The average pecan grower can be characterized as:
    • Interested in potentially adopting hedge-pruning for their operation.
    • Perceiving positive financial revenue impacts from hedge-pruning.
    • Significantly concerned about the cost (equipment and labor) of hedge-pruning.
    • Requiring more information and evidence before adoption.

Economics Component - Planned Activities – Year 2

  • Create a final report on year 1 survey results incorporating new grower survey responses received during spring and summer 2021.
  • Begin collecting and assembling cost, revenue, and production data for the economic assessment of the costs and returns to pecan-hedging.
  • Work with project team members as field trial data becomes available to translate findings into a cost-benefit framework.

Pecan grower perceptions of hedge-pruning and barriers and drivers of adoption

Brief summaries of responses by pecan growers to key survey questions regarding perceptions of hedge pruning, willingness to adopt, and stakeholder needs to make an informed decision for their operation.

Pecan Grower Farm Size and Use of Hedge-Pruning

Current adopters of hedge-pruning tend to be larger operations (33% of farms larger than 100 acres hedge-prune compared to 20% of farms less than 100 acres)

Pecan Grower Familiarity with Hedge Pruning vs. Use of Hedge-Pruning

The majority of pecan growers are familiar with hedge-pruning but do not currently hedge-prune for management of mature pecan trees.

Pecan Grower Perceptions of the Effects of Hedge-Pruning (Part 1 of 2)

The majority of pecan growers perceive a positive impact on nut quality and yield, but the positive impact is stronger for quality.

Pecan Grower Perceptions of the Effects of Hedge-Pruning (Part 2 of 2)

 The majority of pecan growers perceive a reduction of pest pressures from hedge-pruning

Other perceived benefits stated by growers:

 Improved spray coverage

 Reducing alternate bearing

 Less wind and storm damage

 Better air flow

Pecan Grower Perceptions of the Cost and Profitability of Hedge-Pruning

Pecan hedge-pruning is perceived by the majority of growers as expensive.  The majority of growers believe that hedge-pruning would not improve or worsen their operations’ bottom-lines.  However, nearly half of growers perceive the financial benefits would outweigh the cost.

Grower Willingness to Adopt Hedge-Pruning and Barriers to Overcome to Facilitate Adoption

All surveyed growers are open to adopting hedge-pruning in their operation.  To assist in the decision whether hedge-pruning is appropriate, growers stated they need to see more evidence from field trials, evidence on the economic returns from the practice, and alleviation of concerns regarding the cost of hedge-pruning.

Key barriers and opportunities identified by growers for adoption of hedge-pruning:

More evidence on the economic and biological benefits of hedge-pruning

Reduction in hedge-pruning costs

Evidence on the economic returns to hedge-pruning

Educational & Outreach Activities

10 Consultations
6 Webinars / talks / presentations

Participation Summary:

49 Farmers
10 Ag professionals participated
Education/outreach description:

Below are list of presentations related to this project:

2021

Toledo, P., K. Phillips, J. Schmidt and A.L. Acebes-Doria. Effects of mechanical hedge-pruning on aphid-parasitoid interactions in southeastern US pecan orchards. ESA Southeastern Branch Meeting. Virtual. March 29-31

2021

Phillips, K., and A.L. Acebes-Doria. Impacts of summer and winter hedge-pruning on pest populations in pecans. ESA Southeastern Branch Meeting. Virtual. March 29-31

2021

Acebes-Doria, A.L. Updates on pecan integrated pest management. North Carolina Pecan Growers Meeting. Virtual. March 23

2021

Acebes-Doria, A.L. Pecan IPM. ESA Eastern Branch Meeting. Virtual. March 24

2020

Phillips, K. and A.L. Acebes-Doria. Impacts of hedging on pest populations in pecans. 2020 ESA Annual Meeting, Virtual, Nov. 11-25

   

2020

Acebes-Doria, A.L. Overview of the UGA Entomology Pecan Research and Extension Programs. Georgia Pecan Grower Conference. Tifton, GA, Sept. 10

Second Year Outcomes/Outputs/Impacts

Publications:

Phillips, K., Toledo, P., Cottrell, T., Shaipiro-Ilan, D., Schmidt, J.M., & Acebes-Doria. Effects of hedging on pest populations and natural enemies in pecan systems. Agricultural Ecosystems and Environment - In preparation

Slusher, E.D., Cottrell, T., Gariepy, T., Schmidt, J.M., & Acebes-Doria, A. Molecular unraveling of parasitoids and hyperparasitoids associated with pecan aphids. Bulletin of Entomological Research – In review with co-authors

Slusher, E.D., Cottrell, Schmidt, J.M., & Acebes-Doria. Vertical stratification of aphids and pararasitoids in pecans. Environmental Entomology - In review with co-authors

Wu, S., Toews, M, Cottrell, T., Schmidt, J.M., & Shaipiro-Ilan, D. Toxicity of Photorhabdus luminescens and Xenorhabdus bovienii bacterial metabolites to pecan aphids (Hemiptera: Aphididae) and the lady beetle Harmonia axyridis (Coleoptera: Coccinellidae). Under review – Journal of Invertebrate Pathology. 

Presentations:

Toledo, P.F.S.; Schmidt, JM.; Acebes-Doria AL. 2021. Do mechanical hedge-pruning strategies influence the activity of parasitoid wasps in pecan orchards? In: Annual Meeting of the Entomological Society of America.

Toledo, P.F.S.; Phillips, K.; Schmidt, JM.; Acebes-Doria AL. 2021. Effects of mechanical hedge-pruning on aphid-parasitoid interactions in southeastern US pecan orchards. In: Southeastern Branch Meeting of the Entomological Society of America.

Workshops:

2021 Virtual Orchard Tour at the Georgia Pecan Growers Association's Annual Conference

Graduate student training:

Kate Phillips (MS Student)– Nearly finished with M.S. degree and scheduled to defend her thesis by May 2022.

Pedro Toledo (PhD Student) – One year into his program. Has collected data from all sites, and is currently processing. He’s now trained on many aspects of working in pecan systems. He also successfully applied for a SSARE student grant to enhance work in pecan systems and predator-prey interactions.

Undergraduate student training:

During the first two years, five undergraduates were trained on multiple aspects of conducting field research in pecan systems. All students learned how to drive the lifts, collect each type of sample, sort collected samples, and for insects, identify basic groups of insect taxa.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.