Progress 08/15/09 to 08/14/11
Outputs
OUTPUTS: Agar diffusion was conducted in order to screen each fraction for antimicrobial properties. Each fraction demonstrated significant inhibition zones compare to sterile water and 10% bleach. Total phenolics demonstrated the most inhibition and were most effective against E. coli O157:H7, Salmonella, and Listeria strains. Proanthocyanidins were the least effective and only demonstrated inhibition zones for Listeria and Yersinia. Gaseous ClO2 provided a range of 2-6 log CFU/g reductions in the scale-up packaging approach. High concentration of ClO2 and close proximity to the chemical reagents caused discoloration of the treated blueberries. The discoloration effect was reduced during the double bag approach. Further studies are needed to determine the best concentration of ClO2 that will maximize antimicrobial effect without discoloring the produce. Results indicate that eight weeks of wild blueberry consumption decreased the maximum force of vasoconstriction (Fmax) in the adult SHR-B aortic rings. The specific site of their action seems to be the sGC-NO pathway, since its inhibition significantly increased Fmax and implies that wild blueberries may play a significant role in enhancing this pathway in the SHR animal model. Field control of blueberry spanworm larvae on wild blueberry (crop-year) with insecticides revealed prespray populations were not significantly different among the treatments. A 4.5 oz/a rate of Delegate WG significantly reduced the seasonal density of blueberry spanworm larvae in comparison with the untreated checks but the 3.0 oz/a rate was not effective Effectiveness of Mycotrol O as a mix with GF-120 NF Fruit Fly Bait for control of blueberry maggot fly. Analysis of Variance and Tukeys HSD used to compare the seasonal density of BMF adults captured on Pherocon AM traps found that GF-120 alone and in combination with Mycotrol O significantly reduced the seasonal density of BMF adults. Use of Hopperfinder barrier tape to prevent immigration of blueberry maggot fly into fruit-bearing blueberry fields Analysis of all three years of data suggests that over 3 years and across several fields the barrier tactic will significantly reduce flies and maggots. Mummyberry incidence was not greater with bumble bees compared to honeybees as pollinators. In fact there is no evidence to suggest that pollinators played a role in enhancing infection; the incidence of mummyberry was equivalent in cages with inoculum that had no bees compared to those with either honeybees or bumble bees. The fungicide treated plots had significantly fewer mummyberry blighted stems than the control plots. The forecast application schedule allowed for one fewer fungicide application than the Calendar schedule while providing the same disease control. Soil pH values during the year of sulfur application were 5.18 for the control and 5.16 for the sulfur treated plots. Soil pH of samples taken in the first crop year (2002) indicated that sulfur treated plots had a lower pH after one year. After eight years, the soil pH was still lower than the untreated control. PARTICIPANTS: Participants include the growers who allowed us use of their land for experimental plots. TARGET AUDIENCES: Target audiences include the 575 wild blueberry growers who have farms in the State of Maine and growers in New Hampshire and Massachusetts. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The antimicrobial screening study has shown that the wild blueberries have antimicrobial activity against major foodborne/human pathogens tested. The positive results can be future tested using viable culture counts to determine specific log reductions of pathogens by the minimum concentration of wild blueberry fractions. The significant results of this research could provide more options to the management of bacterial infections and could solve the problem of antibiotic resistance being encountered by current drug and antibiotic therapies. Gaseous ClO2 has been shown to reduce the population of natural flora or inoculated E. coli O157:H7 on wild blueberries. Further optimization of a pallet enclosure and treatment system will enhance the effectiveness of ClO2 against natural flora and pathogens. In conjunction with other sanitization procedures already used in wild blueberry processing facilities, the combination of gaseous ClO2 treatment and forced air cooling could be inexpensively adapted to commercial post-harvest processing, providing a safer product with increased shelf life, without significantly affecting the visual quality of the blueberries. This is the first study to demonstrate that wild blueberries improve vasomotor tone by acting on the NO-sGC pathway in the adult SHR. Additionally, wild blueberries reduced the release of vasoconstrictor prostanoids, namely PGI2 and TXA2, and therefore may be a potentially beneficial treatment for endothelial dysfunction. Delegate WG is an EPA-registered, reduced-risk, broad-spectrum insecticide offering the advantage of low toxicity to beneficial insects and a longer residual than SpinTor. A reduced, 4.5 oz/a rate of Delegate (full rate is 6.0-7.0 oz/a) provided excellent control of spanworm larvae. Use of this lower rate will result in lower material cost per acre for growers. A further reduced 3 oz/a rate was ineffective. : Although infestation was high in all three treatments, numbers were significantly lower than the untreated check in plots treated with Mycotrol O and with a combination of Mycotrol O and GF-120 so may be on adults of the blueberry fly to reduce maggot infestation. When we assess the results over several sites and three years there is an average trend of fewer flies and less infestation inside the barrier strip relative to the unprotected control. While this method will not provide consistent reductions in maggot infestation every year it will provide significant reduction in maggot infestation over the long-term. This study suggests that pollinators in the lowbush blueberry production system may not play as dominant a role in secondary infection of mummyberry as has previously been believed. The forecast schedule of fungicide application recommended two applications of fungicide and produced the same level of mummy berry blight control as the Calendar method fungicide application that required three applications of fungicide. This is an improvement over the calendar method of fungicide application and can produce the same level of control but with fewer applications of fungicide. Berry yield was significantly higher in low pH plots, compared to high pH plots.
Publications
- Kristo, A.S., A.Z. Kalea, D.A. Schuschke, and D.J. Klimis-Zacas. 2010. A wild blueberry enriched diet (V. angustifolium) improves vascular tone in the adult Spontaneously Hypertensive Rat (SHR), J. Agric. and Food Chem. doi:10.1021/jf101839qu.
- Del Bo, C., D. Klimis-Zacas, A. Kristo, P. Riso, M. Porrini, and S. Ciappellano. 2010. The temporal effect of a wild blueberry (V. angustifolium)-enriched diet on vasomotor tone in the Sprague-Dawley rat, Nutrition, Metabolism and Cardiovascular Diseases. doi:10.1016/j.numecd.2010.05.004.
- Del Bo , C., S. Ciappellano, D. Klimis-Zacas, D. Martini, C. Gardana, P. Riso and M. Porrini. 2010. Anthocyanin absorption, metabolism, and distribution from a wild blueberry-enriched diet (Vaccinium angustifolium) is affected by diet duration. J. of Agric. Food Chem. 58:2491-2497.
- Del Bo, C., D. Martini, S. Vendrame, P. Riso, S. Ciappellano, D. Klimis-Zacas, and M. Porrini. 2010. Improvement of lymphocyte resistance against H2O2-induced DNA damage in Sprague-Dawley rats after eight weeks of a wild blueberry (Vaccinium angustifolium)-enriched diet; Mutation Research/Genetic Toxicology and Environmental Mutagenesis. doi:10.1016/j.mrgentox.2010.08.013.
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Progress 08/15/09 to 08/14/10
Outputs
OUTPUTS: The minimum inhibitory concentrations and inhibition degrees of two wild blueberry powders against Helicobacter pylori were assessed, and gaseous ClO2 was assessed as an alternative method for E. coli control in commercially harvested wild blueberries. The effects of wild blueberries on young spontaneously hypertensive rats were studied in relation to arterial vasoconstriction and vasodilation. Field studies were conducted for insecticidal control of blueberry thrips, flea beetle larvae, blueberry maggot fly (BMF); mechanical and biological control of BMF; and the impact of insecticides over time on mound ants in blueberry fields. The construction of a predictive degree-day model for thrips emergence continued into the fourth year of a five year study. Baited traps for attracting and capturing BMF were assessed for effectiveness. The effects of late pruning of the same plants over multiple cycles were assessed for thrips control, flower-bud production and fruit development. The presence and prevalence of viruses in local and migratory honeybees was examined. Shade and brood removal effects on bumblebee foraging activity were also examined. The effects of exposure to imidacloprid on honeybee and bumblebee growth, survival and disease susceptibility were studied. Honeybee colonies were exposed to acetamiprid during bloom to assess tolerance. Foraging movement behavior of honeybees and bumblebees was recorded. The impact of ant mounds on soil nutrients was assessed. Vertical distribution of BMF in different tree species on field borders was quantified with sticky traps. Development of blueberry spanworm on different phenological blueberry plant stages was compared. Fungicides for control of Septoria leaf spot were evaluated. The carryover effect of controlling leaf rust in the prune year was examined in the next crop year. Mummy berry disease and Botrytis blossom blight forecasting programs were continued. Education and surveys for Septoria and Valdensinia leaf drop diseases were conducted. The effect of soil pH reduction on nutrient uptake, soil nutrients, plant growth and yield continued to be examined. The study of effects of gypsum on soil nutrient uptake and field-level responses was continued. A spot treatment trial was conducted to assess the efficacy of a mesotrione/clethodim tank mix in controlling broadleaf weeds and grasses. Fall applications of tribenuron methyl continued to be assessed for the best timing for bunchberry control in prune and crop year fields. The wild blueberry Extension Education program was continued in order to improve best management practices and minimize use of unnecessary pesticides and fertilizers. The negative effects of fruit consumption and positive effects of insect pest consumption by wild turkeys continued to be assessed through grower surveys, turkey diet analysis, and turkey behavior and field use. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Wild Blueberry growers in Maine and general public. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Both wild blueberry powders had anti H. pylori activity and the minimum concentrations are being determined. Gaseous ClO2 reduced E. coli on blueberry surfaces. Vasoconstriction was reduced and vasodilation was increased by wild blueberries, and there was a protective effect to the arteries. Assail insecticide had mixed results against thrips while Delegate looked promising; reduced-rate Delegate and Assail were effective against flea beetle larvae; ground application of reduced-risk insecticides had mixed results in reducing BMF adults and pupae. Baited BMF trap effectiveness was limited to monitoring fly occurrence and determining threshold population levels. Pruning prior to mid-may resulted in little loss of potential yield, while mid-May to mid-June pruning resulted in 20-30 percent losses and pruning after mid-July resulted in almost total flower bud and crop loss. A predictive model showed that pruning June 15 would provide good thrips control. Bumblebee foraging was positively related to temperature and the amount of brood present. Imidacloprid did not appear to affect honeybee colony strength over time or incidence of disease in a caged trial, but initially set back colonies in a field trial. Honeybees appeared to be tolerant of acetamiprid both in the short-term and long-term. Imidacloprid negatively affected bumblebee brood at the end of bloom, but not workers. Foraging behavior of honeybees and bumblebees will be put into a computer simulation model to compare pollination efficacy. Mound ants significantly increased soil nutrients in their vicinity. BMF preferred oak, maple and birch early on and oak, maple and poplar later in the season, but there was no significant height preference over time. Pristine and Proline significantly reduced leaf drop from Septoria in one field only, but there were no differences in yield for any treatment. All tested fungicides reduced leaf drop from rust in the prune year, but there were no differences in yields in the following crop year. Growers are using the mummy berry forecasting system, and some have started mummy berry plots in their own fields to track the disease for local spray timing. Valdensinia was identified in nine ME growers fields and the fields were burned to try to eradicate the disease; spread and control methods are still being studied. Soil pH reduction led to inconsistent results in soil nutrient uptake, plant growth and yield from year to year. Split applications and varying rates of gypsum were applied to blueberry fields but there are no results at this time. Tribenuron methyl application in the prune year resulted in poor efficacy on bunchberry and reduced yields. The October crop year treatment was most effective, which differs from previous years, but dry conditions early in the study may have affected results. Extension education included new factsheets, Spring Grower meetings, field demonstration sessions and public interviews. Growers perceived wild turkeys as giving little to no benefit and were concerned with damage; however, behavior analysis showed that turkeys spent more time in blueberry fields prior to fruiting, and crop loss was low.
Publications
- Yarborough, D. and J. D Appollonio. 2009. Spot treatments of broadleaf weeds and grasses in wild blueberry fields using a mesotrione/clethodim tank mix. Proceedings of the Northeastern Weed Science Society. 63:8.
- Huebner, J. 2010. Wild turkey foraging behavior and crop depredation on wild blueberry farms in Maine. MS Thesis, University of Maine, Orono. 76 pg.
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