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
  • 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
Cultivar 0.32 0.28 0.86 0.09
HT X Ctvr 0.27 0.05 0.39 0.91

Plant Pathology

Objectives:

1) Determine relative impacts of hedge-pruning young and older trees by comparing disease in hedged-pruned and non-pruned young and older pecan trees.

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

Materials and Methods:

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 in 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. 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 lift at approximately 5-6, 8-9, 11-12 and 13+ m. Sample heights above ground were 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. Fruit weight included the shuck. Shoot samples of the previous seasons growth were collected as for the leaf and fruit samples, but in January 2021. Shoots were measured and the number of scab lesions counted for each shoot. Data are were analyzed using a generalized linear mixed model with fixed effects of treatment, tree height and tree side, and random effects of replicate. Means separation was by Tukey’s HSD (α = 0.05). 

Results and Discussion

We have completed preliminary analysis of two experiments (The Ray City and Marshallville locations). Scab was very mild at the Ray City location (Caddo is only moderately susceptible), while Desirable is very susceptible to scab.  Thus, mean scab severity on mature fruit at the Ray City location was <7.0% at all heights, regardless of summer or winter pruning management (Fig 1A). Numerically, there was slightly more sever scab at 5 and 9 m on the summer pruned compared to the winter pruned trees. Severity was numerically less low in the canopy regardless of summer or winter pruning.  Despite mostly low severity, scab impacted fruit weight (Fig 1B). On mature fruit at the Marshallville location, mean scab severity was >16% (Fig. 2A). Scab severity was similar at all height in the non-hedge-pruned trees, but in the hedge pruned trees there was significantly less sever scab at 11 m height compared to lower in the canopy, and to the severity in the non-hedged trees. Scab had a profound effect on fruit weight (Fig 2B).

Fig 1A. Scab severity on mature pecan fruit at different heights in the canopy of mature Caddo pecan trees in an orchard at Ray City, GA. Trees in the orchard received either summer or winter hedge-pruning management. Means with different letters are significantly different based on Tukey’s HSD. Error bars indicate 95% confidence intervals. Fig 1B. The relationship between fruit weight and scab severity.

Fig 2A. Scab severity on mature pecan fruit at different heights in the canopy of mature Desirable pecan trees in an orchard at Marshallville, GA. Trees in the orchard received were either non-hedge pruned or revived winter hedge-pruning management. Means with different letters are significantly different based on Tukey’s HSD. Error bars indicate 95% confidence intervals. Fig 2B. The relationship between fruit weight and scab severity.

Entomology

Objectives:

  • Determine relative impacts of hedge-pruning young trees by comparing pest insect populations in hedged-pruned and non-pruned young trees. (Marshallville)
  • Determine relative impacts of hedge-pruning older trees by comparing insect pest populations in hedged-pruned and non-pruned older trees. (Montezuma)
  • Define the effects of timing (summer versus winter) on hedge-pruning of pecans on pest and beneficial insect populations. (Ray City)

Note: The beneficial insect population data are still being processed, hence are not reported here.

Objective 1 Entomology Results: Marshallville

Yellow pecan aphid (YPA) complex population. In June, no significant interaction was found between hedging treatment and canopy location on YPA populations (Table 1: June). The number of YPA’s did not differ between the upper and lower canopy but more YPA’s were found in the hedged than non-hedged trees (Table 1: June). In July, no significant interaction was found between treatment and canopy location (Table 1: July). There was no significant difference between hedged trees and non-hedged trees but there were more YPA’s in the lower canopy than the upper canopy (Table 1: July). In August, there was an interaction between treatment and canopy location, and the upper canopy of the hedged trees had more YPA’s than the other three treatment and canopy combinations (Table 1: August).

Black pecan aphid population. There was no interaction effect between the treatment and canopy location in the black aphid populations (Table 2: August). The BPA populations did not differ between hedged and non-hedged trees, however, the upper canopy had significantly more black aphids than the lower canopy (Table 2: August).

Phylloxera galls. In June, there was no significant interaction between the treatment and canopy locations (Table 3: June). There was no significant difference between hedged and non-hedged trees and none with canopy location as well (Table 3: June). In July, there was no significant interaction between canopy location and treatment (Table 3: July). There were significantly more galls located in the non-hedged trees than the hedged trees, but there was no difference between the upper and lower canopies of the trees (Table 3: July). In the month of August, there was no interaction between canopy location and hedged or non-hedged, however the lower canopy had more galls than the upper canopy and non-hedged trees had more than hedged trees (Table 3: August).

Pecan leaf scorch mite population. In August, no significant interaction was found between canopy location and treatment. When individually analyzing canopy location and treatment, there was no significant difference between hedged trees and non-hedged trees but there were more PLSM in the lower canopy than the upper canopy (Table 4: August).

Insect-related nut injury before harvest. Nut samples from June and July with insect-related injuries were very low to warrant statistical analysis. In the month of June, 588 nuts were collected and only 15 had pecan nut casebearer damage (~2.6% infestation rate). In the month of July, 478 nuts were collected, and only 6 had pecan nut casebearer damage (1.25 % infestation rate), and no nuts had shuckworm damage.

Evaluation of insect injury on harvested nuts. Overall, insect-related damage on harvested nuts were low. Of the 435 nuts collected, only 23 had shuckworm damage (5.28% infestation rate) and no stink bug or nut curculio damage was found.

Table 1. Mean number of yellow complex aphids sampled in 2020 from the upper and lower canopies of 25-year old ‘Desirable’ pecan trees that were hedged and not hedged.

Treatment

Canopy Location

 

Mean ± SEM No. Total Yellow aphid complex per two leaves

 

 

June

July

August

Hedged

Upper

 

2.63 ± 0.52^

3.60 ± 0.84

18.33 ± 3.68 a

 

Lower

 

2.57 ± 0.49^

7.00 ± 1.46*

2.93 ± 1.38 bc

Non-Hedged

Upper

 

1.58 ± 0.32

2.75 ± 0.25

4.68 ± 1.01 b

 

Lower

 

1.90 ± 0.32

4.80 ± 1.44*

1.48 ± 0.43 c

 

Interaction Effects (P Value)

0.5962

0.5557

0.0017

 

Non-hedged/Hedged (P Value)

0.0324

0.1690

0.0002

 

Upper/Lower (P Value)

0.6965

0.0331

0.0001

Columns with * following the means have a significant higher value between canopy locations using a student t-test.
Columns with ^ following the means have a significantly higher value between treatments
Columns with a letter following the means have an interaction between the canopy location and treatment.

Table 2. Mean number of black pecan aphids sampled in August 2020 in 25-year old ‘Desirable’ pecan trees from the upper and lower canopies of hedged and non-hedged trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total Black Aphids per two leaves

 

 

 

August

 

Hedged

Upper

   

3.48 ± 1.07*

 
 

Lower

   

0.63 ± 0.49

 

Non-Hedged

Upper

   

2.58 ± 1.71*

 
 

Lower

   

0.23 ± 0.10

 
 

Interaction Effects (P Value)

 

0.6441

 
 

Non-hedged/Hedged (P Value)

 

0.3538

 
 

Upper/Lower (P Value)

 

0.0220

 

Columns with * following the means have a significant higher value between canopy locations using a student t-test.
During the June and July sampling, black pecan aphids were not found on the leaf samples.

Table 3. The mean number of Phylloxera galls per sample taken from the upper and lower canopies of hedged and non-hedged 25-year old ‘Desirable’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total Phylloxera galls per two leaves

 

 

June

July

August

Hedged

Upper

 

0.10 ± 0.07

0.08 ± 0.03

0 ± 0

 

Lower

 

1.15 ± 0.99

0.55 ± 0.46

0.25 ± 0.15*

Non-Hedged

Upper

 

0.53 ± 0.09

0.55 ± 0.20^

0.68 ± 0.36^

 

Lower

 

1.93 ± 0.49

1.58 ± 0.50^

2.10 ± 1.05*^

 

Interaction Effects (P Value)

0.8331

0.5250

0.6089

 

Non-hedged/Hedged (P Value)

0.0643

0.0359

0.0076

 

Upper/Lower (P Value)

0.0545

0.1120

0.0328

Columns with ^  following the means have a significantly higher value between treatments using a student t-test.
Columns with * following the means have a significant higher value between canopy locations using a student t-test.

Table 4. The mean number of total pecan leaf scorch mites from each sample of 25-year old ‘Desirable’ pecan trees taken from the upper and lower canopies of hedged and non-hedged trees in August 2020.

Treatment

Canopy Location

 

Mean ± SEM No. Total Pecan leaf scorch mites per two leaves

 

 

 

August

 

Hedged

Upper

   

2.00 ± 1.44

 
 

Lower

   

28.20 ± 11.13*

 

Non-Hedged

Upper

   

1.13 ± 0.54

 
 

Lower

   

12.40 ± 4.89*

 
 

Interaction Effects (P Value)

 

0.3132

 
 

Non-hedged/Hedged (P Value)

 

0.2232

 
 

Upper/Lower (P Value)

 

0.0019

 

Columns with * following the means have a significant higher value between canopy locations using a student t-test.
During the June and July sampling, pecan scorch mites were not found on the leaf samples.

Objective 2 Entomology Results: Montezuma

Yellow aphid complex populations. In the ‘Cape Fear’ variety, in the month of June, there was no interaction effect between canopy location and treatment (Table 1: June). There was also no significant difference in populations for both canopy location and treatment. In of July, there was no significant difference between yellow aphid complex populations in hedged trees and non-hedged trees (Table 1: July). In August, there was no interaction between canopy location and treatment. Yellow aphid numbers were not statistically different between hedged trees and non-hedged trees, but the lower canopy of the trees had significantly more aphids than the upper canopy (Table 1: August). For ‘Stuart’ variety in June, there was no interaction between the canopy location and treatment. Yellow aphid numbers were the same on hedged trees and non-hedged trees, however there were less aphids in the upper canopy than the lower canopy (Table 2: June). In July, there was no significant difference between hedged trees and non-hedged trees (Table 2: July). For August, no significant interaction was found between treatment and canopy location. Yellow aphid populations did not differ significantly between hedged trees and non-hedged trees. More aphids were found in the lower canopy than the upper canopy (Table 2: August).

Black pecan aphids. Black pecan aphids were only present in August. For both the ‘Cape Fear’ and ‘Stuart’ varieties, there was no significant interaction between the canopy location and treatment. For ‘Cape Fear’, the lower canopy had more black pecan aphids than the upper canopy, but the number of aphids between the hedged trees and non-hedged trees was similar (Table 3). For ‘Stuart’, the upper canopy had lesser aphids than the lower canopy, and the hedged trees had lower number of aphids than the non-hedged trees (Table 4).

Pecan leaf scorch mite (PLSM). Pecan leaf scorch mites were not present until later in the growing season. In July, for both varieties, there was no difference in PLSM numbers between hedged trees and non-hedged trees. In August, there was no interaction between canopy location and treatment for both varieties. The amount of PLSM did not significantly vary between the canopy location or treatment (Tables 5 and 6).

Leaf miners. No leaf miners were found in June and July for both the ‘Cape Fear’ and ‘Stuart’ varieties. In August, there was no interaction effect between treatment and canopy location in the ‘Cape Fear’ variety, and similar degree of damage was found between canopy locations and treatments (Table 7). For the ‘Stuart’ variety in August, the canopy location and treatment had no interaction. The upper canopy had lesser leaf miner damage than the lower canopy, and but the hedged trees and non-hedged trees had similar amounts of damage (Table 8).

Insect related nut injury before harvest. In June, a total of 682 nuts were sampled. In these nuts, only one had evidence of pecan nutcase bearer infestation. In the month of July, a total of 240 nuts were sampled from the lower canopy, however no damage from either pecan nutcase bearer or shuckworm was found.

Insect injury on harvested nuts. At harvest, a total of 563 nuts were collect between the ‘Cape Fear’ and ‘Stuart cultivars. Of the 563 nuts samples, no shuckworms were found, and only four nuts had any damage. No injuries from nut curculio or stink bugs were found on the harvested samples.

Table 1. Mean number of yellow complex aphid nymphs and adults sampled in 2020 from the upper and lower canopy of ‘Cape Fear’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total Yellow Complex Aphids per two leaves

 

 

June

July

August

Hedged

Upper

 

0.43 ± 0.08

0.57 ± 0.27

 

Lower

 

0.53 ± 0.15

0.37 ± 0.13

5.64 ± 1.98*

Non-Hedged

Upper

 

0.20 ± 0.10

0.40 ± 0.17

 

Lower

 

0.63 ± 0.19

0.97 ± 0.32

5.10 ± 1.47*

 

Interaction Effects (P Value)

0.2206

 

0.9746

 

Non-hedged/Hedged (P Value)

0.4171

0.1515

0.7384

 

Upper/Lower (P Value)

0.1101

 

0.0017

Columns with * after values had significantly more yellow aphid complex aphids in the lower canopy than the upper canopy.
In July, samples were only taken from the lower canopy.

Table 2. Mean number of yellow complex aphid adults and nymphs sampled in 2020 from the upper and lower canopy of ‘Stuart’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total Yellow Complex Aphids per two leaves

 

 

June

July

August

Hedged

Upper

 

0.37 ± 0.14

/

2.60 ± 1.70

 

Lower

 

0.64 ± 0.23*

0.93 ± 0.35

28.75 ± 10.02*

Non-Hedged

Upper

 

0.11 ± 0.11

/

1.85 ± 0.42

 

Lower

 

0.83 ± 0.34*

0.77 ± 0.15

15.45 ± 6.02*

 

Interaction Effects (P Value)

0.1195

/

0.3439

 

Non-hedged/Hedged (P Value)

0.3243

0.6667

0.2819

 

Upper/Lower (P Value)

0.0167

/

0.0026

Columns with * after values had significantly more yellow aphid complex aphids in the lower canopy than the upper canopy.
In July, samples were only taken from the lower canopy

Table 3. Mean number of black pecan aphids sampled per tree from the upper and lower canopies of 45-year old pecan trees of the ‘Cape Fear’ variety.

Treatment

Canopy Location

 

Mean ± SEM No. Black pecan Aphids per two leaves

 

 

 

August

 

Hedged

Upper

   

0.03 ± 0.03

 
 

Lower

   

0.37 ± 0.03*

 

Non-Hedged

Upper

   

0 ± 0

 
 

Lower

   

0.53 ± 0.43*

 
 

Interaction Effects (P Value)

 

0.4671

 
 

Non-hedged/Hedged (P Value)

 

0.9507

 
 

Upper/Lower (P Value)

 

0.0162

 

Columns with * after values had significantly more black pecan aphids in the lower canopy than the upper canopy.
In the months of June and July, no black pecan aphids were found in the leaf samples

Table 4. Mean number of black pecan aphids sampled in 2020 from the upper and lower canopy of 45-year-old ‘Stuart’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Black pecan aphids per two leaves

 

 

 

August

 

Hedged

Upper

   

0 ± 0

 
 

Lower

   

0.28 ± 0.14*

 

Non-Hedged

Upper

   

0.11 ± 0.11^

 
 

Lower

   

4.59 ± 2.37*^

 
 

Interaction Effects (P Value)

 

0.0930

 
 

Non-hedged/Hedged (P Value)

 

0.0412

 
 

Upper/Lower (P Value)

 

0.0157

 

Columns with * after values had significantly more black pecan aphids in the lower canopy than the upper canopy.
Columns with ^ after values had significantly more black pecan aphids in the non-hedged trees than the hedged trees.
In the months of June and July, no black pecan aphids were found in the leaf samples

Table 5. Mean number of total pecan leaf scorch mites in each sample from the upper and lower canopies of 45-year-old hedged and non-hedged ‘Cape Fear’ pecan trees in 2020.

Treatment

Canopy Location

 

Mean ± SEM No. total scorch mites per two leaves

 

 

 

July

August

Hedged

Upper

   

/

0.07 ± 0.07

 

Lower

   

1.67 ± 0.84

0.30 ± 0.30

Non-Hedged

Upper

   

/

0 ± 0

 

Lower

   

0.80 ± 0.21

0.03 ± 0.03

 

Interaction Effects (P Value)

 

/

0.8634

 

Non-hedged/Hedged (P Value)

 

0.9183

0.3356

 

Upper/Lower (P Value)

 

/

0.4582

In July, samples were only taken from the lower canopy.
No pecan leaf scorch mites were found in the samples in the month of June.

Table 6. Mean number of pecan leaf scorch mites sampled in 2020 from the upper and lower canopies of 45-year-old hedged and non-hedged ‘Stuart’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. total scorch mites per two leaves

 

 

 

July

August

Hedged

Upper

   

/

2.84 ± 1.11

 

Lower

   

0.76 ± 0.62

7.23 ± 5.33

Non-Hedged

Upper

   

/

0.20 ± 0.15

 

Lower

   

0.27 ± 0.03

5.85 ± 4.42

 

Interaction Effects (P Value)

 

/

0.4864

 

Non-hedged/Hedged (P Value)

 

0.4650

0.3315

 

Upper/Lower (P Value)

 

/

0.1567

In July, samples were only taken from the lower canopy
No pecan leaf scorch mites were found in the leaf samples in the month of June

Table 7. Mean number of leaf miners sampled in 2020 from the upper and lower canopies of 45-year-old hedged and non-hedged ‘Cape Fear’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total Leaf miners per two leaves

 

 

August

Hedged

Upper

   

0.20 ± 0.16

 
 

Lower

   

0.49 ± 0.07

 

Non-Hedged

Upper

   

0.10 ± 0.10

 
 

Lower

   

0.50 ± 0.26

 
 

Interaction Effects (P Value)

 

0.7548

 
 

Non-hedged/Hedged (P Value)

 

0.7913

 
 

Upper/Lower (P Value)

 

0.0819

 

In the months of June and July, no leaf miners were found in the leaf samples.

Table 8. Mean number of leaf miners sampled in 2020 from the upper and lower canopies of 45-year-old hedged and non-hedged ‘Stuart’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total Leaf miners per two leaves

 

 

August

Hedged

Upper

   

0.21 ± 0.11

 
 

Lower

   

0.56 ± 0.20

 

Non-Hedged

Upper

   

0.21 ± 0.11

 
 

Lower

   

0.59 ± 0.15

 
 

Interaction Effects (P Value)

 

0.8384

 
 

Non-hedged/Hedged (P Value)

 

0.8384

 
 

Upper/Lower (P Value)

 

0.0576

 

In the months of June and July, no leaf miners were found the in the leaf samples.

Objective 2 Entomology Results: Ray City

Yellow aphid complex. In the ‘Creek’ cultivar, for all three sample dates, there was no interaction between the canopy location and treatment. There was also no significant difference between treatments and canopy locations in any sample date (Table 1). In the ‘Caddo’ cultivar, the same results as the ‘Creek’ cultivar were found for all three sample dates (Table 2).

Black pecan aphids. No black pecan aphids were found in samples collected in June and July for both the ‘Creek’ and ‘Caddo’ varieties. For both varieties, there was no interaction between canopy location and treatment on black aphid numbers, and no significant difference between hedged and non-hedged treatments as well as no difference between upper and lower canopy (Table 3).

Leaf miners. In June, leaf miners and the associated damage were only counted in the ‘Creek’ cultivar. No significant interaction between the canopy location and hedging treatment was observed, and both canopies had similar populations of leaf miners as well as both hedging treatments (Table 4: June). The lower canopies of both the ‘Creek’ and ‘Caddo’ cultivars had more scorch mites in July than the upper canopies, however there was no difference between the treatments for either as well as no significant interactions (Table 4: July, Table 5: July). For the ‘Creek’ cultivar in August, there was no significant interaction between the treatment and canopy location, and similar to July, only canopy location was significantly different with the lower canopy having more (Table 4: August). A significant interaction was observed in August in the ‘Caddo’ cultivar. The lower canopy of summer hedged trees had the highest numbers of leaf miner damage, while the upper canopies of both the summer hedged and winter hedged trees had the least amount of damage (Table 5: August).

Pecan leaf scorch mites. For both the ‘Creek’ and ‘Caddo’ cultivars, no pecan leaf scorch mites (PLSM) were found in June. In July for the ‘Creek’ cultivar, there was no significant interaction between the treatment and canopy location. The trees hedged in the summer had similar amounts of PLSM as the trees hedged in the winter, but the lower canopies of the trees had more PLSM than the upper canopy (Table 6: July). For the ‘Caddo’ cultivar in July, results were similar to the ‘Creek’ cultivar with no significant interaction between canopy location and treatment, and the only significant difference being between canopy locations (Table 7: July). In August, there was no significant interaction in the ‘Creek’ cultivar between the canopy location and treatment, and similar to July, the lower canopy had more PLSM than the upper canopy but no significant difference between treatments (Table 6: August). There was significant interaction between the treatment and canopy location in the August samples of the ‘Caddo’ cultivar. The lower canopy of winter hedged trees had the most PLSM of all the treatment and location combinations while the upper canopies of both summer and winter hedged trees had the least (Table 7: August).

Early season nut injury In June, 990 nuts were sampled, and in July, 980 nuts were sampled. In both months, no pecan nut casebearer or shuckworm injury was recorded.

Harvest.  At harvest, 540 nuts were collected. In all the nuts collected, none had any injury related to nut feeding insects.

Table 1. The mean number of yellow aphid complex adults and nymphs in summer and winter hedged trees sampled in 2020 from the upper and lower canopies of 25 year-old ‘Creek’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total Yellow Complex Aphids per two leaves

 

 

June

July

August

Summer

Upper

 

4.16 ± 2.26

0.30 ± 0.20

0.23 ± 0.19

 

Lower

 

4.03 ± 0.73

0.27 ± 0.09

0.40 ± 0.06

Winter

Upper

 

2.70 ± 1.26

0.27 ± 0.12

0.30 ± 0.12

 

Lower

 

2.40 ± 1.10

1.07 ±0.38

0.47 ± 0.09

 

Interaction Effects (P Value)

0.9432

0.1677

1.0000

 

Non-hedged/Hedged (P Value)

0.2163

0.1670

0.5628

 

Upper/Lower (P Value)

0.8532

0.1550

0.2201

Table 2. The mean number of yellow aphid complex adults and nymphs in summer and winter hedged trees sampled in 2020 from the upper and lower canopies of 25 year-old ‘Caddo’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total Yellow Complex Aphids per two leaves

 

 

June

July

August

Summer

Upper

 

3.93 ± 1.64

0.37 ± 0.13

0.37 ± 0.22

 

Lower

 

5.10 ± 0.56

0.47 ± 0.32

0.27 ± 0.15

Winter

Upper

 

4.90 ± 1.93

0.20 ± 0.20

0.13 ± 0.09

 

Lower

 

2.93 ± 1.13

0.20 ± 0.12

0.27 ± 0.14

 

Interaction Effects (P Value)

0.0616

0.8321

0.4010

 

Non-hedged/Hedged (P Value)

0.4133

0.1450

0.4010

 

Upper/Lower (P Value)

0.5793

0.7144

0.9015

Table 3. The mean number of total adult and nymph black pecan aphids per sample taken in August 2020 from the upper and lower canopies of 25 year-old summer and winter hedged ‘Creek’ and ‘Caddo’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total black pecan aphids per two leaves

 

 

Creek

 

Caddo

Summer

Upper

 

0 ± 0

 

0 ± 0

 

Lower

 

0.13 ± 0.13

 

0.47 ± 0.32

Winter

Upper

 

0.03 ± 0.03

 

0.03 ± 0.03

 

Lower

 

0.03 ± 0.03

 

0.07 ± 0.03

 

Interaction Effects (P Value)

1.0000

 

0.1571

 

Non-hedged/Hedged (P Value)

0.4680

 

0.3867

 

Upper/Lower (P Value)

0.5787

 

0.0611

No black pecan aphids were found in samples in the months of June and July

Table 4. The mean number of total leaf miners per sample taken in 2020 from the upper and lower canopies of 25 year-old summer and winter hedged ‘Creek’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total leaf miners per two leaves

 

 

June

July

August

Summer

Upper

 

0.40 ± 0.21

1.73 ± 1.01

2.23 ± 0.84

 

Lower

 

0.10 ± 0.06

5.63 ± 1.30*

9.03 ± 1.24*

Winter

Upper

 

0.07 ± 0.03

1.43 ± 0.13

2.46 ± 0.42

 

Lower

 

0.30 ± 0.15

4.57 ± 1.03*

8.30 ± 1.24*

 

Interaction Effects (P Value)

0.0927

0.5893

0.6345

 

Non-hedged/Hedged (P Value)

0.8766

0.3488

0.9805

 

Upper/Lower (P Value)

0.8869

0.0020

0.0010

Columns with * following the means have a significant higher value between canopy locations using a student t-test

Table 5. The mean number of total leaf miners per sample taken in 2020 from the upper and lower canopies of 25 year-old summer and winter hedged ‘Caddo’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. Total leaf miners per two leaves

 

 

 

July

August

Summer

Upper

   

2.00 ± 0.17

2.80 ± 0.15 c

 

Lower

   

5.63 ± 0.98*

11.67 ± 0.94 a

Winter

Upper

   

1.37 ± 0.47

3.23 ± 0.20 c

 

Lower

   

3.77 ± 0.87*

7.50 ± 1.38 b

 

Interaction Effects (P Value)

 

0.3880

0.0185

 

Non-hedged/Hedged (P Value)

 

0.0798

0.0672

 

Upper/Lower (P Value)

 

0.0023

0.0001

Columns with * following the means have a significant higher value between canopy locations using a student t-test
Columns with letters following the means have an interaction between the treatment and canopy location
No leaf miners were found in the samples in the month of June

Table 6.  The mean number of total pecan leaf scorch mite adults, nymphs, and eggs per sample taken in 2020 from the upper and lower canopies of 25 year-old summer and winter hedged ‘Creek’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. total scorch mites per two leaves

 

 

 

July

August

Summer

Upper

   

0 ± 0

0.23 ± 0.23

 

Lower

   

30.37 ± 26.51*

1.70 ± 1.23*

Winter

Upper

   

1.50 ± 1.31

0.33 ± 0.24

 

Lower

   

23.73 ± 6.83*

7.57 ± 3.71*

 

Interaction Effects (P Value)

 

0.9626

0.2425

 

Non-hedged/Hedged (P Value)

 

0.5237

0.1573

 

Upper/Lower (P Value)

 

0.0184

0.0366

Columns with * following the means have a significant higher value between canopy locations using a student t-test
No PLSM were found in June

Table 7. The mean number of total pecan leaf scorch mite adults and nymphs per sample taken in 2020 from the upper and lower canopies of 25 year-old summer and winter hedged ‘Caddo’ pecan trees.

Treatment

Canopy Location

 

Mean ± SEM No. total scorch mites per two leaves

 

 

 

July

August

Summer

Upper

   

0.96 ± 0.82

0.17 ± 0.17 c

 

Lower

   

140.7 ± 50.64*

3.70 ± 0.25 b

Winter

Upper

   

0 ± 0

0 ± 0 c

 

Lower

   

87.6 ± 28.59*

11.26 ± 2.89 a

 

Interaction Effects (P Value)

 

0.5352

0.0170

 

Non-hedged/Hedged (P Value)

 

0.2645

0.0600

 

Upper/Lower (P Value)

 

0.0002

0.0001

Columns with * following the means have a significant higher value between canopy locations using a student t-test
Columns with letters following the means have an interaction between the treatment and canopy location
No PLSM were found in the samples in the month of June

Entomopathogen

Results show that the entomopathogenic fungus (Beauveria bassiana) was higher in non-hedged plots in Marshallville, where the young trees are planted.

 

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

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.