Progress 09/01/13 to 08/31/18
Outputs
Target Audience:Pecan producers, shellers and accumulators, consumers, other scientists, general public, cooperative extension personnel Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A demonstration orchard has been planted on the grounds of the 1890 land grant in Georgia, Fort Valley State University. The planning and development process (planting) have involved minority students and the standing orchard is being used to expose minority students to pecan production and agricultural practices. Students formerly trained: Ms. Tzu-Chin Liu graduated with a Master of Science degree in Entomology from the University of Georgia and her research assistantship was entirely funded by this project. Another student in economics at the University of Georgia is completing her Ph.D (re: the above economic results) with funding from this project. How have the results been disseminated to communities of interest?The website: Pecan.ipmpipe.org is the go-to source for pecan information in the U.S. Developed at TAMU it is in the process of being turned over for IT management to the Southern Region IPM Program. Items include an overview of Organic Pecan Certification, a searchable list of OMRI products, a searchable Pecan Insect Check List (200+ phytophagous insects), a List of Expert Organic Pecan Scientists, and a seamless interface with the standard Pecan ipmPIPE website resource that includes access to an interactive Make Your Own Pecan budget, and a Make your Own Risk Assessment for pecan nut casebearer. This new information resource is designed to be economically maintained and easily upgraded as new research merits translation for industry application. A number of minority and other students were directly involved in the project in the capacity of seasonal workers, field trips of agricultural classes and other demonstrations by the PIs. Oral presentations: ~20 presentations to pecan grower groups around the Southeast (GA, AL, FL) and Southwest (TX) have been provided that discussed the findings from this project. These included talks at major producer events such as the annual Southeastern Fruit and Vegetable meeting in Savannah, Georgia and the AL,FL, GAand TX annual pecan grower association meetings. These will continue in the coming off-season meetings -post project termination. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Results from consumer surveys and choice experiments indicate that there is demand for organic pecans if supply challenges can be overcome. Analyses found that consumers on average are willing to pay a substantial premium of $2.53/8oz for organic shelled pecans over conventionally produced pecans, a premium of nearly 30% in the study areas. Organic insecticide tests: The results indicated that Grandevo and Doubletake controlled pecan weevil and Intrepid Edge and Entrust SC did not control pecan weevil. Doubletake, Intrepid Edge and Entrust SC at 10 oz formulation/acre controlled kernel-feeding Hemipterans and Grandevo and Entrust at 6 oz formulation/acre did not control kernel-feeding Hemipterans. Doubletake and Entrust at 10 oz formulation/acre controlled hickory shuckworm and Grandevo, Intrepid Edge and Entrust at 6 oz formulation/acre did not control hickory shuckworm. Entrust and Grandevo results are encouraging for organic pecan growers since these are approved for use in organic production. Entrust at 4 or 6 oz/acre was an ineffective treatment against all three pests. Over all trials, average efficacies for treatments with some potential use for pecan growers for pecan weevil control were: 78% for Entrust SC at 10 oz/acre, 91% for Grandevo at 3 lb/acre, 100% for Intrepid Edge at 6.4 oz/acre, and 80% for Doubletake at 4 oz/acre. Efficacies for kernel-feeding stinkbug control were: 100% for Entrust SC at 10 oz/acre, 0% for Grandevo at 3 lb/acre, 100% for Intrepid Edge at 6.4 oz/acre and 83% for Doubletake at 4 oz/acre. Efficacies for hickory shuckworm control were: 67% for Entrust SC at 10 oz/acre, 0% for Grandevo at 3 lb/acre, 95% for Intrepid Edge at 6.4 oz/acre and 94 % for Doubletake at 4 oz/acre. New aerial sampling methods for pecan aphids indicated substantial immigration of aphids into orchards heretofore unrecognized as a contributing problem to aphid suppression. Fire ants are important predators in pecan orchards on the ground but become pests by feeding on biological control agents if allowed to forage within the tree canopy. Chlorpyrifos is labeled for use on pecan tree trunks to keep ants out of trees. A comparison of 2 available organic methods - Tanglefoot barrier vs Bird Stop treated tree trunks - indicated that Tanglefoot was effective for two weeks while Bird Stop excluded ants for 4 weeks. Comparisons of the biodiversity of fauna in natural habitats and conventional vs organic orchards on the ground using pitfall traps and in the canopy using aerial Malaise traps were conducted. Results indicated that conventional orchards supported far fewer arthropods throughout the season than the other treatments and biodiversity in organic production was closer to the natural habitats based on the indicator species used in the analyses. Pecan scab disease evaluations were conducted in two ways: by conventional orchard chemical treatments at two locations and by evaluations of pecan cultivars for resistance-tolerance levels in south Alabama. Chemicals: In all experiments conducted over 5 years in Georgia, the fungicide treatment applied was Bordeaux mixture (4 lb CuSO4:1 lb hydrated lime, for the 1st spray; followed by 6 lb CuSO4:2 lb hydrated lime for the 2nd - 6th sprays applied a t 100 gallons per acre. There was a significant reduction in the severity of scab on fruit due to the Bordeaux mixture treatment at the Byron location in 2011 (F=12.3, P=0.0005) and 2014 (F=4.4, P=0.04), and at the Colquitt location in 2014 (F=30.0, P<0.0001). The percentage reduction in severity of scab was 43.9%, 16.2% and 24.4%, respectively. At the Colquitt location there was an increase (16.3%) in the severity of scab on fruit of Bordeaux mixture-treated trees (F=8.8, P=0.003). In the remaining experiments, there was no significant differences between treatments. In other experiments a total of 6-8 fungicide applications were made at 2-3 week intervals starting in late April and through late August. By late August there was a significant effect on pecan scab on fruit in June (F=39.2, P<0.0001), with scab severity on the control = 71.8% fruit shuck area with symptoms, and on the treated plots = 54.3% fruit shuck area. Fruit weight in late August was also significantly greater on plots receiving Bordeaux mixture (F=14.1, P=0.0002), with fruit weight = 13.1 g on control plots, and 15.1 g on treated plots, respectively. In the organic alternatives experiment (comparing a control, and various organic treatments (Bordeaux mixture, Regalia, Serenade, Nordox, Sulfur, Sodium bicarbonate and Compost tea), there were significant differences among treatments in mid-June (F=7.5, P<0.0001). By late August, there was a highly significant effect of treatment (F=8.6, P<0.0001) on the severity of pecan scab among treatments. Again, Regalia had the least severe pecan scab (24.8%), followed by Serenade (40.0%). Only the Regalia and Serenade treatment showed consistent effects throughout the season. Ultimately, the solution to pecan scab will evolve around the use of pecan cultivars with natural resistance/tolerance to the pathogen. Results from cultivar evaluations of scab susceptibility demonstrated that cultivars are available that contain disease resistance and that data will be forthcoming. Weed suppression: Organic weed control methods, including mechanical mowing, flaming, mulching with pine bark nuggets, vinegar application, and a combination of pine bark mulch and vinegar were evaluated over three years. The combination of pine bark mulch and vinegar provided the greatest overall vegetative control at all sampling dates. Mulching with pine bark nuggets alone provided similar control for the first year, but control decreased in subsequent years. Vinegar alone and flaming treatments provided some vegetative control without the use of mulch, but were inferior overall to the mulch-vinegar combination. While the combination of mulch and vinegar provides superior weed control compared to the other strategies, the presence of mulch can interfere with nut harvesting.
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2017
Citation:
Shapiro-Ilan, D. T. Cottrell, C. Bock, K. Mae, D. Boykin, L. Wells, W. Hudson and R. Mizell. 2017. Control of pecan weevil with microbial biopesticides. J. Econ. Entomol. In press.
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Progress 09/01/15 to 08/31/16
Outputs
Target Audience:Pecanproducers, potential producers, homeowners, associated associated industry people, people involved in and/or associated with in general agricultural production. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Minority students were exposed to pecan production practices at Ft. Valley State University via visits to a pecan orchard and by helping with establishing and upkeep of the demonstration orchard. How have the results been disseminated to communities of interest?Use of presentations at producer meetings, via the ipmPIPE association, personnel contacts and print materials in scientific and popularmedia. What do you plan to do during the next reporting period to accomplish the goals?Finish all the objectives and initiate and complete publications and the websites. Charge the extension investigators with the results and publicize them to the public andpecan stakeholders.
Impacts
What was accomplished under these goals?
IA. Intercrops for enhancement of aphidophagous insects in pecan orchards. Cool season crops of white Dutch clover and hairy vetch and intercrops were sewn in a large replicated field trial for two seasons. Intercrops of 'clover +vetch' and 'vetch' had significantly higher abundance of alternate prey and ladybeetles than intercrops of clover or mowed sod. The canopies of pecan trees with 'clover + vetch' or 'vetch' intercrops had significantly more ladybeetles. Trunk sprays were tested to prevent red imported fire ants and argentine ants from interfering with aphidophagous insects in pecan tree canopy. Methyl anthranillate, "Bird Stop", as a trunk spray was found to be an effective repellent to remove foraging fire and argentine ants from the pecan tree canopy. IIA. For weevils, treatments consisted of one entomopathogenic nematode application (Steinernema carpocapsae applied at 2 billion nematodes per acre) and one entomopathogenic fungus application (Beauveria bassiana Mycotrol®O applied at 2 x 1012 per acre). Treatments were made to the soil under the tree canopy in May-June, 2014 and repeated in 2015. Additionally, Grandevo® was applied at 3 lbs per acre. The bacterial product (C. subtsugae) was applied to the canopy 3 times from mid-August to mid-September. To assess treatment effects, pecan weevil adult emergence was monitored with Circle and cone traps. Damage to nuts was assessed at harvest. Results indicated that management regimes suppress pecan weevil relative to control plots. Also, results indicated that all microbial treatments (nematodes & fungi) persisted for approximately 2 months. Grandevo applied alone indicated that itperformed at an equal level compared with a standard chemical treatment. IIB. A fermenting molasses spray was applied to enhance beneficial efficacy on aphids. Yellow and black pecan aphids were significantly lower in the molasses-treated trees than in the nontreated control, blackmargined aphid abundance was not affected by the spray. Ladybeetles were more abundant and lacewings were less abundant in the molasses treated trees. A new sampling technique for measuring the abundance of aphids and aphidophagous insects in the pecan tree canopy was developed by using a large suction trap to collect aphids from samples of the air in the tree canopy. The trap measured dynamics of aphid and aphidophagous insect populations that were not evident in the conventional leaf samples. The method has promise as a more effective method of assessing pest and beneficials biodiversity in pecan and other orchard crops. IIC. Bordeaux mixture is historically an industry standard for scab control. Bordeaux mixture on pecan scab was compared to non-treated control trees. Bordeaux mixture (Cu/lime) was applied as 4:1:100 - 4 lb CuSO4:1 lb hydrated lime:100 gallons water for 1st spray (prepollination) and 6:2:100 - 6 lb CuSO4:2 lb hydrated lime:100 gallons water for 2nd-6th spray (1 week after 1st spray, then every 3 weeks until mid-August). No effect of Bordeaux mixture occurred in either 2014 or 2015, although scab severity was numerically less on the treated trees in 2015. Bordeaux mixture demonstrated only limited efficacy atreducing scab severity. IID. Pecan cultivars were evaluated for innate scab resistance at Fairhope, AL. Experimental trees were managed using organic practices and fungicides were not applied over a 3 year period. Percent coverage of nuts by pecan scab fungus was assessed. Cultivars having the highest incidence of nut scab were 'Desirable' (96%), 'Farley' (99%) and 'Melrose' (92%). Cultivars having the lowest incidence and coverage (0-1%) of nut scab were 'Adams 5', 'Excalibur', 'Jenkins', 'Kanza', 'Excel', 'McMillian' and 'Prilop'. Many cultivars did not yield marketable pecans due to scab including 'Curtis', 'Desirable', 'Farley', 'Melrose', and 'Sumner'. 'Adams 5', 'Elliott', 'Kanza', and 'Prilop' performed the best, averaging 48, 45, 46, and 48 percent kernel, respectively, from 2013-2015. Interestingly, the cultivar 'Elliott' exhibited only moderate resistance to scab (50% nut coverage) but was among the best performers. Cultivars that produced the highest percentage of Grade 1 pecans were 'Kanza' (48%), 'Adams 5' (43%), 'Elliott' (43%), and 'Prilop' (42%). III.In progressas data can only be collected once project field results have been further developed IV.Comparisons of epigeal and canopy occupying insects in conventional vs organic pecan orchards indicated that conventional orchards were virtually devoid of most common epigeal and canopy species found in the orchards without conventional insecticide/fungicide applications. V. Evaluations of farmer knowledge is in progress as data can only be collected once project field results have been further developed. General extension efforts are as follows: The Pecan ipmPIPE Beltwide Program facilitates access to relevant information by stakeholders using the internet. The public website at http://pecan.ipmpipe.org/ supports 200+ organized, searchable web pages. The central element is a Toolbox that contains sections on: 1) Educational Materials 2) Pesticide Search Engines; 3) Pecan Library; and, 4) an interactive pecan budget calculator, templates for records and forms, and videos and E-learning tools for users. Many additional elements are also available. The Organic Pecan Program has interfaced with the Pecan ipmPIPE Beltwide Program to provide an Organic Pecan Outreach Component to better inform producers on organic pecan production. This component will be featured on the Home Page on the Pecan ipmPIPE website and Educational Materials tailored to organic production will be added/integrated into the website to allow intuitive navigation for all pecan stakeholders. The pesticide search engines now include OMRI designations for materials labeled for use on pecan. The text for the Home Page is 90% complete and will be launched shortly. Ongoing work is also being conducted on pecan arthropod and pathogen lists to make them more comprehensive, including text information on each species, and to illustrate each species with photographs to aid identification. The organic pecan producers are also being encouraged to participate in the PNC Risk Window Network. A tracking function is also being added to provide an aid to measuring impact of this new organic component on the pecan industry. Additionally, 8 presentations were provided to pecan growers on various aspects of the project. An extension bulletin has been drafted along with a video on results from the project.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Journal of Invertebrate Pathology 124, 114116
- Type:
Other
Status:
Published
Year Published:
2015
Citation:
The Pecan Grower Magazine 24:26-30
- Type:
Websites
Status:
Published
Year Published:
2016
Citation:
http://sepga.com/index.html
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2016
Citation:
http://www.pakinsight.com/?ic=journal&journal=106
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
HORTSCIENCE 51(6):653663
- Type:
Other
Status:
Published
Year Published:
2015
Citation:
The Pecan Grower Magazine. 26(2): 10-17
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2016
Citation:
HortScience
|
Progress 09/01/14 to 08/31/15
Outputs
Target Audience:Pecan producers, industry representatives, general public, extension agents, other professional scientists involved in commercial or non-commercial pecan production across the Pecan belt including the states represented in the grant of AL, FL, GA, and TX via scientists contacts and via the web nationally and internationally. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Trainings: the PIs have provided presentations in FL and GA to several hunderd pecan growers and their families. FVSU has developed a demostration orchard for students who have been exposed to pecan production. UGA has both undergraduate and graduate level student funded and working on the project as does the ARS. The pecan ipmpipe website serves as the main extension resource for pecan production of all types for the U.S. and Mexico. How have the results been disseminated to communities of interest?Through PI presentations and through the pecan ipmpipe website. What do you plan to do during the next reporting period to accomplish the goals?Continue objectives with most research being focused on repeat of some experiments, development of economic data, development of the pecan.ipmpipe website, transfer of results to clientele, andperforming experiments that were delayed by delays in funding to several Co_PIs.
Impacts
What was accomplished under these goals?
I. Large plot tests. Research was conducted at three separate farms at three locations: USDA-ARS research station, Byron, GA; Cleveland Organics, LLC, Fort Valley, GA, DGW Farms, Colquitt, GA. The experiment was conducted with two levels of insect pest & disease management, i.e., treated plots versus non-treated controls. The insect control treatment against pecan weevil consisted of one entomopathogenic nematode application (Steinernema carpocapsae applied at 2 billion nematodes per acre) and one entomopathogenic fungus application (Beauveria bassiana applied at 5 x 1012 per ha). These treatments were made to the soil under the tree canopy in May-June, 2014. Additionally, at the Byron and Fort Valley location, Grandevo (Chromobacterium subtsugae) was applied at 3 lbs per acre. The bacterial product (C. subtsugae) was applied to the canopy 3 times from mid-August to mid-September (when the pecan weevil is emerging). Results indicated that the pest management regimes suppress pecan weevil relative to control plots. Exp. B. In a separate but closely related test, the impact of the relatively new product C. subtsugae (Grandevo) applied alone as a pecan weevil control measure was investigated. Four blocks of 2.5 acres were sprayed with Grandevo at 3 lbs per acre (recommended rate); the applications were made four times between mid-August and mid-September. An equal number of 2.5 acre plots were sprayed four times with a standard chemical insecticide, and an untreated control was also included. Grandevo as a canopy spray, performed at an equal level with a standard chemical treatment. II. A,B. Optimize weevil and aphid control. ARS Shapiro-Ilan,and Bock: Results indicated that organic tactics for pecan weevil control including entomopathogenic nematodes, fungi and bacteria show great promise. Particularly, the relatively new organic product (Grandevo) based on the bacterium, Chromobacterium subtsugae caused pecan weevil suppression akin to the use of insecticides. A regime of C. subtsugae along with entomopathogenic fungi (Beauveria bassiana) and beneficial nematodes (Steinernema carpocapsae) caused lower pecan weevil infestation levels compared with a non-treated control. Application of entomopathogenic fungus, B. bassiana, in conjunction with composted manure, resulted in enhanced persistence and efficacy of the fungus. It was discovered that the pecan weevil pupal cell possess antimicrobial properties that suppress entomopathogenic fungi; this novel finding will be explored further. Disease control: in large plot tests Bordeaux mixture caused reduced pecan scab severity and increased fruit weight. In small plot tests treatments of Regalia and Serenade consistently reduced scab severity throughout the season; some other treatments (e.g., compost tea, %, Sodium bicarbonate =77.3%, and Nordox) exhibited less favorable results. UGA-Dutcher, A field trial was conducted to determine the efficacy of AG1000, an organic spray material for aphid control in pecans manufactured by Teraganix Co. AG1000 did not control aphids. Methyl carbitol, myristate and methyl anthranillate were tested for efficacy as ant repellents on cover crop plants with limited success. Three separate experiments were initiated to investigate organic methods of control of pecan diseases, particularly pecan scab, caused by Fusicladium effusum. A total of 6-8 fungicide applications were made at 2-3 week intervals starting in late April and through late August. By late August there was a significant effect on pecan scab on fruit in June (F=39.2, P<0.0001), with scab severity on the control = 71.8% fruit shuck area with symptoms, and on the treated plots = 54.3% fruit shuck area. Fruit weight in late August was also significantly greater on plots receiving Bordeaux mixture (F=14.1, P=0.0002), with fruit weight = 13.1 g on control plots, and 15.1 g on treated plots, respectively. In the organic alternatives experiment (comparing a control, and various organic treatments (Bordeaux mixture, Regalia, Serenade, Nordox, Sulfur, Sodium bicarbonate and Compost tea) there were significant differences among treatments in mid-June (F=7.5, P<0.0001). By late August, there was a highly significant effect of treatment (F=8.6, P<0.0001) on the severity of pecan scab among treatments. Again, Regalia had the least severe pecan scab (24.8%), followed by Serenade (40.0%). Only the Regalia and Serenade treatment showed consistent effects throughout the season. D. Test promising pecan cultivars for resistance to disease. IIC, D: Wells-Auburn:Evaluated organic methods of weed control including mulch, vinegar, flaming, and combinations thereof., b. Evaluated organic methods of leaf and nut scab control including Serenade, Nordox, Regalia, Bordeaux Mixture, and Sulfur. 2. Pecan cultivar evaluation: a. Continued to evaluate pecan cultivars for scab susceptibility at two locations in Fairhope and Shorter, AL. b. Evaluated scab control in both high and low input orchards. Organic weed control methods, including mechanical mowing, flaming, mulching with pine bark nuggets, vinegar application, and a combination of pine bark mulch and vinegar were evaluated over the past three years. The combination of pine bark mulch and vinegar provided the greatest overall vegetative control at all sampling dates. Mulching with pine bark nuggets alone provided similar control for the first year, but control decreased in subsequent years. Vinegar alone and flaming treatments provided some vegetative control without the use of mulch, but were inferior overall to the mulch-vinegar combination. While the combination of mulch and vinegar provides superior weed control compared to the other strategies, the presence of mulch can cause difficulties when harvesting the crop. III. Too early in project to accomplish, data not in yet. IV. Mizell UFL: In an organic and a conventionally managed orchard in south Georgia ground-level pitfall traps and aerial Malaise traps were used to determine and compare the arthropod biodiversity within these two orchard types. Within the organic orchard, the effects of fungicide use on arthropod populations were also assessed in a similar manner. Trapping was conducted over the course of the pecan growing season from June until the beginning of harvest in October. Significant differences were observed in both the epigeal arthropods and the aerially trapped species between the organic and conventional orchards. The organic orchard had higher species richness and biodiversity in both sample types. Fungicides used in the organic orchard had little detectable effects on arthropod populations. V. Harris-TAMU:: Real time risk assessment for pecan nut casebearer was on-line for the 2014-2015 season with a volunteer Cooperator Network of ~40 pecan producers recruited and trained to participate in inputting real time information from across the pecan belt that was then analyzed, processed, verified and posted to the website for public use in decision making. The resulting web pages were subsequently accessed by >4,000 users of the website indicating that ~20% of the target producer audience was able to directly access this information. Brown- FVSU: this effort deals with the project's demonstration aspects. Three cultivars of pecan, Desirable, Moreland, and Pawnee, were transplanted and replicated four times in a randomized complete block design in organically prepared soil on FVSU Farm during the first quarter of the winter months of this year, 2015. 1) Questionnaires are being prepared in preparation for taste tests of the nuts in the future, 2) tree seedlings are growing beautifully, 3) the initial tree height measurements have been recorded and three subsequent growth height measurements will be recorded each year, once during the spring, summer and fall, respectively.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Shapiro-Ilan, D.I., Mizell, R.F. An insect pupal cell with antimicrobial properties that suppress an entomopathogenic fungus Journal of Invertebrate Pathology. 124:114-115
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Cowell, B., D. T. Johnson, R. Mizell and E. Garcia. 2015. Monitoring insect and pest damage in pecan in Arkansas. ISHA ActaHort. 1070: 151-157.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2105
Citation:
Shapiro-Ilan, D. I., Mizell, R. F. III. 2015. A novel discovery in pecan weevils pupal cell may lead to a new control method for pecan diseases such as scab. The Pecan Grower Magazine. 26(2): 10-17.
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Progress 09/01/13 to 08/31/14
Outputs
Target Audience: Pecan producers, industry representatives, general public, extension agents, other professional scientists involved in commercial ornon-commercialpecan production across the pecan belt including the states represented in the grant of AL, FL, GA, and TX via scientists contacts and via the web nationally and internationally. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Harris-TAMU-pecanipmPIPE website:was on-line again for the 2014 season with a volunteer Cooperator Network of ~40 pecan producers recruited and trained to participate in inputting real time information from across the pecan belt. The project has also begun developing an Organic Pecan component to emphasize this option in pecan management in cooperation with Mizell. The outreach provided by thewebsite will improve program delivery using the internet. How have the results been disseminated to communities of interest? Via the pecan.ipmPIPE website, the primary Beltwide dissemination vehicle; presentations by each of the PIs to their respective state producer organization annual meetings, presentations to other scientists atprofessional meetings anda 1.5 day exchange of ideas and progress at the annual regional pecan project (S-1049)meeting held at the Noble Foundation in Ardmore, OK. What do you plan to do during the next reporting period to accomplish the goals? Auburn University - will continue all pecan scab evaluations in 2015. ARS- will repeat arthropod and disease experiments as warranted and add new treatments as available. University of Georgia: I, IIB: The pecan aphid control experiments will be conducted to determine the efficacy of the integration of 3-5 sprays of organic insecticides to the tree crown with an air-blast sprayer. The first spray will be applied to suffocate aphid eggs at the overwintering sites on the shoots of the tree in February while the trees are dormant. The second and subsequent sprays will applied to control Spring (May) and Summer (late August) pecan aphid populations materials tested for efficacy against foliage-infesting aphids that reach the action thresholds designated by the Georgia Cooperative Extension Service of 50 aphids per leaf in the Spring and Early Summer and 20 aphids per leaf during the late Summer and Fall for yellow pecan aphids and blackmargined aphids (combined count) and/or 1 aphid per compound leaf for black pecan aphids over the entire season. Two application rates of the following commercial products will be tested: a natural insecticide, Trilogy® (Certris USA L.L.C., Columbia, MD, USA, www.certisusa.com); two oil formulations, Suffoil-X® (Bioworks. Inc., Victor, NY, USA, www.bioworksinc.com), Oroboost™ (Oro Agric, Inc., Trophy Club, TX, USA, www.oroagri.com); and, a soap, Des-X™ (Certris USA L.L.C., Columbia, MD, www.certisusa.com). The treatments will be tested on 25 year-old ‘Desirable’ pecan trees in a 6 acre (150 trees) orchard block that will be managed by organic production methods. The treatments including a nontreated control will be applied to four single tree replications in a complete randomized block design. Aphid densities will be measure before treatment and then 2 days, 1 wk, 2 wk and 3 wk post-treatment in each replication of each treatment. Data will be analyzed for normality, and then transformed to approximate a normal distribution when necessary; and finally with analysis of variance and mean separation techniques. Efficacy and application costs will be used to support subsequent economic analysis and extension activities. Host plant resistance studies will be conducted in pecan to determine the susceptibility of pecan cultivars to pecan aphids. Aphids will be studied in clip cages on the multi-cultivar pecan trees to determine the population parameters – time from birth to first reproduction, and number of nymphs produced per adult - so that we can calculated the natural rate of increase for each aphid species on each cultivar. In the clip cage studies a single adult aphid is placed in a small enclosure (clip-cage) on the leaf surface and observed each day until the first nymph is born. The adult is then removed from the cage the entire life cycle of the nymph is observed in the clip-cage at two day intervals until the aphid dies. During the observation period the number of days to the maturity of the aphid and the number of nymphs produced by the aphid are recorded. Five aphids will be observed on each cultivar for each of the three aphid species. Trials coincide with peak activity of each aphid species and are typically run in May and June for yellow pecan aphid; July and August for Blackmargined aphid; and, September and October for black pecan aphid. Biological control will be studied by direct observations after altering orchard floor design and by experimentation. Aphidophagous insects will be monitored at two levels in the orchard – on the orchard floor and in the tree canopy – by the following methods: Direct counts on pecan foliage samples; Fan traps in the tree canopy; Sweep net samples ground cover plants; Traps baited with attractants incl. pheromones, host plant volatiles and honeydew mimics. The orchard floor will be managed for the dual purpose of altering the soil organic matter, providing additional nitrogen for the trees, and providing refuge and alternative food for aphidophagous insects by the following scheme: Plant crimson clover and hairy vetch as a cover crop in the Fall after harvest; Apply organic fertilizer to the soil in February and March; Cut the clover-vetch crop and plant iron clay peas with a seed drill in April; Cut the peas and plant buckwheat in June; Cut the buckwheat when aphids begin the increase in the pecan canopy in late August. Control of aphids will be achieved by attracting the aphidophagous insects into the tree canopy with a honeydew mimic – 1 pt molasses plus 2 oz brewer’s yeast, fermented for 2 days in 2 qt of water then added 100 gal of water and applied to the foliage with an airblast sprayer. The effects of these control methods will be determined by comparing direct observations of the pests in the orchard before and after the treatments are applied over the entire orchard. The actual efficacy of the methods individually will be determined in concomitant, small- plot, controlled field experiments. These will be conducted at the Ponder Farm of the Coastal Plain Experiment Station. University of Florida: IV, V: The biodiversity experiment comparing epigeal and aerail arthropod species in an organic vs conventionally managed pecan orchards will be repeated. The results will be prepared for publicationat the end of the season following data collection and analyses. All other objectives and procedures originally proposed will be executed.
Impacts
What was accomplished under these goals?
Funding had not been released to the University of Georgia by the end of 2014which represents the proposed work for a number of these project goals. These include goals I., IIB, III anda large percentage of V so this is reflected in this reprot. :UGA-Dutcher,A field trial was conducted to determine the efficacy of AG1000, an organic spray material for aphid control in pecansmanufactured by Teraganix Co. The material was applied ten times at two week intervals from bud break in early May through Sept. Tift Co., GA. A 12 acre plot of 28 year-old ‘Desirable’ pecan trees was transitioned from conventional to organic production beginning in 2014. The AG1000 was applied at a rate of 2.5 gal of formulation per 100 gal of final spray.The results indicated that AG1000 did not control aphids as indicated by the samples taken during two peaks of aphid activity in late August and early October. II.A.UGA-Dutcher, Ants remove beneficial insects that are cultured on alternate prey on the cover crops.Methyl carbitol, myristate and methyl anthranillate were tested for efficacy as ant repellents on cover crop plants with limited success. IIB: ARS-Shapiro-Ilan, Bock: Integrated tactics for control of key insect pests and plant diseases in pecan were investigated in small plot and large plot tests. The research was conducted at three separate farms at three locations: USDA-ARS research station, Byron, GA; Cleveland Organics, LLC, Fort Valley, GA, DGW Farms, Colquitt, GA.The experiment was conducted with two levels of insect pest & disease management, i.e., treated plots versus non-treated controls.These insect control treatments focused on the primary key pest, pecan weevil. The insect control treatment consisted of one entomopathogenic nematode application (Steinernema carpocapsae applied at 2 billion nematodes per acre) and one entomopathogenic fungus application (Beauveria bassiana applied at 5 x 1012 per ha). These treatments were made to the soil under the tree canopy in May-June, 2014. Additionally, at the Byron and Fort Valley location, Grandevo (Chromobacterium subtsugae) was applied at 3 lbs per acre. . To assess treatment effects, soil samples were taken regularly to assess entomopathogen presence and persistence. Pecan weevil adult emergence was monitored with Circle and cone traps. Finally, weevil damage to nuts was assessed at harvest by examining 100 nuts per plot for damage or presence (in the Cleveland and Byron orchards).Grandevo caused levels of pecan weevil suppression akin to the use of chemical insecticides. In other large plots tests, a combined pest management regime of C. subtsugae along with entomopathogenic fungi (Beauveria bassiana) and beneficial nematodes (Steinernema carpocapsae) caused lower pecan weevil infestation levels comparedto anon-treated control.Application of the entomopathogenic fungus, B. bassiana, in conjunction with composted manure, results in enhanced persistence and efficacy of the fungus relative to standard applications. Shapiro-Ilan and Mizell discovered that the pecan weevil pupal cells possess antimicrobial properties that suppress entomopathogenic fungi. IIC: ARS-Bock: Disease control, The effect of Bordeaux mixture on pecan scab was compared to non-treated control trees. In all experiments a total of 6-8 fungicide applications were made at 2-3 week intervals starting in late April and continuing through late August. A single foliar sample was taken in mid-June (when spring shoot growth was completed), and two fruit samples were taken, one in mid-June, and one in late-August. Samples were assessed for scab severity by estimating the extent of symptoms on the fruit shuck surface using standard area diagrams as an aide to ensure accuracy. In large plot tests Bordeaux mixture caused reduced pecan scab severity and increased fruit weight. In small plot tests treatments of Regalia and Serenade consistently reduced scab severity throughout the season; some other treatments (e.g., compost tea, %, Sodium bicarbonate =77.3%, and Nordox) exhibited less favorable results. IIC, D: Auburn University- Wells: a.Evaluated organic methods of weed control including mulch, vinegar, flaming, and combinations thereof., b.Evaluated organic methods of leaf and nut scab control including Serenade, Nordox, Regalia, Bordeaux Mixture, and Sulfur.2.Pecan cultivar evaluation: a.Continued to evaluate pecan cultivars for scab susceptibility at two locations in Fairhope and Shorter, AL. b.Evaluated scab control in both high and low input orchards. III. Nothing to report, too early for this analysis to be conducted. IV: Experiments by UFL-Mizell were set up in an organic and a conventionally managed orchard in south Georgia using ground-level pitfall traps and aerial Malaise traps to determine and compare the arthropod biodiversity within these two orchard types. Within the organic orchard, the effects of fungicde use on arthropod populations were also assessed in a simialr manner. Trapping was conducted over the course of the pecan growing season in cooperation with Bock and Shapiro-Ilanfrom June untilthe beginning of harvest in October. Traps, 4/treatment were set in the field for 4 daysonce every 14 days over the period. Collected arthropods were removed to the lab, identified and quantified according to treatment. Large differences were observedin both the epigeal arthropodsand the aerially trapped species between the organic and conventional orchards. The organic orchard hadhigher species richness and biodiversity in both sample types. Fungicides used in the organic orchard hadlittle detectable effects on arthropod populations.UGA-Dutcher: Aaerial suction traps with a powerful fan at the base that draws air from the canopy of the pecan tree past a fine mesh screen via a volute extended up into the tree were effective in collecting flying and dispersing insects that were not found in conventional scouting methods. Four traps were run from 8:00 AM – 3:00 PM for seven hours twice per week (50 times per season) at two pecan orchards in 2013 from May through October and compared to weekly foliage samples of the lower canopy for measuring the abundance of aphids and other flying and dispersing insects in the tree canopy. 2014 had too many rainy days and attempts to effectively run the traps on a regular basis resulted in damage and a loss of traps. Traps, modified to resist rainfall, have been constructed for trials in 2015. V. Outreach: Harris-TAMU:: Real time risk assessment for pecan nut casebearer was on-line for the 2014 season with a volunteer Cooperator Network of ~40 pecan producers recruited and trained to participate in inputting real time information from across the pecan belt that was then analyzed, processed, verified and posted to the website for public use in decision making. The resulting web pages were subsequently accessed by >4,000 users of the website indicating that ~20% of the target producer audience was able to directly access this information. The project has also begun developing an Organic Pecan component to emphasize this option in pecan management in cooperation withMizell.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Shapiro-Ilan, D.I., Mizell, R.F. An insect pupal cell with antimicrobial properties that suppress an entomopathogenic fungus Journal of Invertebrate Pathology. 124:114-115
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