Solid set canopy delivery systems (SSCDS) offer advantages such as reduced off–target drift and human exposure to chemicals compared to conventional axial–fan airblast sprayers. In this study, six ...different SSCDS configurations (C1–C6) with two different emitter types (E1 and E2) were installed in a vertical shoot position (VSP) trained grapevine and evaluated for spray deposition and coverage during early, mid, and late growth stages. Emitters E1 and E2 had full–circle and hollow–cone spray pattern, respectively. Configuration C1 had a pair of E1 emitters installed per vine at 760 mm above the cordon. Configurations C2 and C3 had 2 pairs of emitters (E2 and E1, respectively) installed per vine near the cordon and C4 was a combination of C1 and a pair of E2 emitters at the cordon. Configurations C5 and C6 had two E2 emitters per vine installed near the drip line, and C5 also had E1 emitters 760 mm above the cordon. Overall, configurations with emitters installed close to both the top and bottom canopy zones (i.e., C1, C4 and C5) provided the best coverage and deposition in a VSP trained vineyard. Deposition for C1, C4 and C5 was 588 ± 159 ng cm−2 (mean ± std. error), 653 ± 123 ng cm−2 and 607 ± 114 ng cm−2, respectively. Coverage for respective configurations was 19 ± 4%, 23 ± 4% and 25 ± 4%. Overall, deposition did not differ significantly between upper–and under–sides of leaves whereas deposition and coverage in the top and bottom zones differed significantly among different configurations.
•Solid set canopy delivery system (SSCDS) was evaluated in a vineyard.•Spray deposition and coverage was quantified for SSCDS configurations.•Identified were the optimal SSCDS configurations.•Emitters had uniform spray when placed in canopy top and bottom sections.
Field investigations were conducted to determine the resting locations of codling moth (Cydia pomonella L.) (Lepidoptera: Tortricidae) males and females in mating disrupted and nondisrupted apple ...(Malus domestica Borkh.) orchard plots. A custom-made sampling device, consisting of a leaf blower converted into a powerful vacuum, yielded 20–24% success in recovering marked moths, released in the tree canopy in orchards. Four collections each were made between 0900 and 1800 hours and 1800 and 2200 hours in 2005. Ninety-four moths were collected during the 1800–2200 hours samples. In mating disruption plots, 42% of females and 22% of males were found in the top third of the tree canopy (3.0–4.5m), 46% females and 43% males in the middle third (1.5–3.0m), and 12% female and 35% male in the lower third (0–1.5m). In nondisrupted plots 36.4% of females and 40% of males were in the top third of the canopy, 36.4% females and 52% males in the middle third, and 27.2% females and 8% males in the lower third of the tree canopy. Daylight vacuum sampling recovered only one female and two male moths from the top, four males from the middle and one male from the lower third of the tree canopy. Release-recapture studies of marked adult codling moths were conducted in 2006–2007 in screened tents to determine within orchard habitats for adult moths during 0900–1800 hours. Of moths recaptured, 14.6% of females and 13.5% of males were from the ground (herbicide strip and drive-row grass) and 32.9% of females and 24.6% of males were captured in the tree canopy 16-h post release, 17.4% of females and 3.4% of males from the ground and 26.5% of females and 38.2% of males in the tree 40-h post release, and 15.1% of females and 18.6% of males from the ground and 15.7 of females and 25.5% of males in the tree 64-h post release. Application of pyrethrum + PBO by using an orchard blast sprayer in 2007 resulted in the recapture of 28% and 37% of laboratory reared male and female moths, respectively, from trees during 0900–1800 h. Our results suggest that distributing pheromone dispensers throughout the tree canopy may be more effective than placing them in one location, such as near the tree crown.
The timing and duration of approaches by male peachtree borer Synanthedon exitiosa Say (Lepidoptera: Sesiidae) to commercial pheromone dispensers placed singly or at high density in peach orchards ...was determined by using field-deployed video cameras and digital video recorders. Cameras were trained on one dispenser, and one standard lure was placed in a peach orchard, and on 12 dispensers in a separate orchard where dispensers for mating disruption had been placed at 371 per hectare. Male moth approaches were video recorded at the peak of peachtree borer annual flight, from 13 to 18 August 2009. The mean approach timing (h:min:sec±SD) during the study period was 11:33:12 ± 00:46:43, 11:43:52 ± 00:45:58, and 11:41:21 ± 00:45:54 AM with the single dispenser, high-density dispensers, and lure, respectively. Day-to-day variability in approach timings suggested that there were no biologically significant differences among treatments. The frequency distribution of approach durations varied among treatments, as the high-density dispensers had mostly short approaches, while the distribution of approaches to the single dispenser and lure was wider. The median (interquartile range) approach duration was 3 (2-4), 1 (1-2), and 4 (2-6) seconds with the single dispenser, high-density dispensers, and lure, respectively. The relative rank of median approach durations was constant throughout the period, indicating differences among treatments. This study showed that the presence of pheromone dispensers for mating disruption did not cause an advancement of peachtree borer diel rhythm of response. Shorter approaches to dispensers placed at high density than singly suggest that dispenser retentiveness is not constant with peachtree borer, which may bias estimates of disruption activity as a function of dispenser density.
•Suppressing flower infection is critical to fire blight management.•A contact sterilant was used to reduce native microflora on apple flowers.•Sterilant effect on subsequent antagonistic yeast ...colonization was variable.•No significant enhancement of fire blight biocontrol through sterilant use was noted.
Due to rapid expansion of organic apple production and issues with antibiotic resistance in conventional production, there is a need for novel strategies to protect orchards from outbreaks of fire blight caused by the bacterial pathogen Erwinia amylovora. The biological control material, Blossom Protect (consisting of two strains of the fungus Aureobasidium pullulans), has shown promising results in some apple growing regions but has shown reduced efficacy in humid apple-growing regions such as the Midwestern and Eastern United States. In an attempt to increase both flower colonization by A. pullulans and disease control efficacy, we applied a contact sterilant to clear the flower niche of native microbial populations 4 hr prior to application of Blossom Protect. Results from four years of field testing showed that application of the contact sterilant resulted in a significant reduction in populations of bacteria, fungi, and native yeast populations; however, all of these microbial populations recovered after 24 h. Examination of fire blight incidence revealed that use of the contact sterilant did not significantly impact disease control. Two applications of Blossom Protect, at 70–80% bloom and full bloom, exhibited the best efficacy in disease control over four years. In addition, we observed marginal differences in the marketability of the final fruit between treatments, each with less than 8% deemed unmarketable due to russet. Our results indicate that niche-clearing of apple flowers did not enhance flower colonization by A. pullulans, nor produce an increase in biological control efficacy. However, our current experimental results (2014–2018) do indicate consistency and an increase in efficacy of Blossom Protect compared to results from previous years.
Host-foraging responses to different intra- and interpatch densities were used to assess three Trichogramma spp. (Hymenoptera: Trichogrammatidae) Trichogramma deion Pinto and Oatman, T. ostriniae ...Pang and Chen, and T. pretiosum Riley — as potential biological control agents for the Indian meal moth, Plodia interpunctella Hübner (Lepidoptera: Pyralidae). Single naïve females were allowed 6 h to forage in Plexiglas arenas with four different spatial arrangements of host eggs, nine single-egg patches), nine four-egg patches, 36 single-egg patches, and 36 four-egg patches. No significant differences were found among species in the number of patches parasitized. As expected, all three species parasitized the most eggs in the 36 four-egg patch treatment and the least in the nine single-egg patch treatment. T. deion parasitized significantly more eggs than T. pretiosum on the nine four-egg patches. T. ostriniae parasitized significantly more patches when intrapatch density was greater, regardless of interpatch density. In contrast, T. deion only parasitized more patches at the greater intrapatch density when the interpatch density was low. Patch density had no effect on T. pretiosum. The spatial pattern of parasitism was more aggregated for T. deion and T. ostriniae in the 36 four-egg patches treatment compared to the 36 single-egg patches treatment. Therefore, intrapatch density was more important than interpatch density for T. ostriniae, and potentially for T. deion, but not for T. pretiosum. T. deion may be the best candidate for augmentative biological control because it parasitized either slightly or significantly more eggs than the other two species in all four treatments. Furthermore, the pattern of parasitism by T. deion in the 36 four-egg patches treatment was the most aggregated among the three species, suggesting a more thorough searching pattern. In contrast, T. pretiosum had the least aggregated pattern of parasitism and therefore may have used a more random foraging pattern.
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•Broad-scale assessment of natural enemies' effect on invasive H. halys eggs in eastern US crops.•Predation, mainly by chewing predators, accounted for the majority of control of H. ...halys eggs.•Parasitism of H. halys eggs by native parasitoids was very low.•Baseline data to evaluate potential future biocontrol programs and native parasitoid adaptation.
Understanding native natural enemy impacts on the invasive brown marmorated stink bug, Halyomorpha halys (Stål), offers insight into the population dynamics of this invasive pest and the potential for biological control. This two-year study offers a broad-scale assessment of mortality factors affecting sentinel and naturally laid H. halys eggs in agroecosystems in the pest’s invaded range in eastern North America. Predation and parasitism rates varied among states and crops, but overall were low. Average maximum levels of biological control were estimated to be about 19% and 20% in 2013 and 2014, respectively. Of the eggs destroyed by natural enemies, chewing predation was the most prevalent. Parasitism by native parasitoids was very low, with adult parasitoids emerging from <1% of eggs averaged across crops, locations, and years; an additional 2.8% of eggs contained partially developed parasitoids. Lower percentages of sentinel H. halys hatched in organically versus conventionally managed crops, and in most cases had higher percentages of predation. Parasitism of sentinel and naturally laid eggs of the native stink bugs Euschistus servus (Say) and Chinavia hilare (Say) averaged 49.3% (±8.6 SE) and 0.6% (±0.3), respectively, across locations and years. Telenomus podisi (Ashmead) was the most common parasitoid parasitizing E. servus and H. halys eggs, but rarely did >1 individual parasitoid emerge from a H. halys egg mass. Parasitism of H. halys eggs by a complex of parasitoids is an important population regulation factor in its native Asian range, but this study found that parasitoids native to eastern US agroecosystems do not provide that service in this introduced region. The greatest potential for biological control of H. halys may be via classical biological control by the Asian parasitoid Trissolcus japonicus (Ashmead), which has recently been detected in both the eastern and western US.
Status Update on Organic Blueberries in Michigan Grieshop, Matthew J; Hanson, Eric; Schilder, Annemiek ...
International journal of fruit science,
2012, 1/1/2012, 2012-01-00, 20120101, Letnik:
12, Številka:
1-3
Journal Article
Recenzirano
Odprti dostop
The Great Lakes Region is an important region of blueberry production in the U.S., producing 30% of the annual U.S. production. In Michigan, blueberry acreage increased from 17,724 acres on 590 farms ...in 2002 to 21,758 acres on 840 farms in 2007. However, despite considerable market potential for organic blueberries, less than 1% of total Michigan blueberry acreage is organically certified. There is high interest and demand for organic blueberries from the Great Lakes Region, and the Michigan State University Blueberry Team has been working on organic production methods over the past 4 years. The establishment of the Michigan State University Organic Blueberry Research and Extension Planting on the Michigan State University campus has been one of the major accomplishments of the Michigan State Uuniversity research team. The objective of this project has been to study practices associated with soil health, nutrition, disease, and insect and weed control. Additional organic blueberry projects in Michigan have focused on studying the interaction of blueberry mulches and compost on nutrient release, and on-station and on-farm testing of OMRI-approved pesticides.
Effects of microhabitat complexity on host foraging by three species of
Trichogramma (
T. deion,
T. ostriniae, and
T. pretiosum) were evaluated under simulated stored product conditions. All three ...species have been considered as potential biological control agents for the Indianmeal moth,
Plodia interpunctella, in retail stores and warehouses. Trials were conducted with single naïve female parasitoids in 10-cm Petri dishes that were either empty, contained flour, or contained millet. Empty 15-cm Petri dishes, which served as a surface area control, comprised a fourth treatment. Females were allowed to forage for sentinel egg disks for 2
h, after which percentages of parasitism and egg mortality were computed. In addition, behavioral observations were made on a subset of the trials.
Trichogramma deion parasitized more eggs than the other two species in the empty dishes and in the dish containing flour. For
T. deion, rates of parasitism and egg mortality were significantly greater in both the small and large empty dishes than in the small dishes containing flour or millet. Parasitism was consistently low for all three species in the grain-filled dishes. Among species,
T. ostriniae spent the most time walking, while
T. pretiosum was the most sedentary. In addition,
T. pretiosum spent significantly more time on the first egg visited compared with subsequent eggs.
T. deion may be the best-suited for use as a biological control agent for
P. interpunctella. However, the potential negative effects of fine-grain habitat complexity should be taken into account when developing a release protocol for
Trichogramma spp.
The effects of shelving type, packaging, and release height on success of Trichogramma deion Pinto & Oatman (Hymenoptera: Trichogrammatidae) parasitizing Plodia interpunctella (Hübner) (Lepidoptera: ...Pyralidae) eggs was studied under laboratory conditions. In trials on multiple-tiered gondola-type or open shelving units, with or without packaging, foraging success was evaluated by comparing parasitism and total mortality rates of sentinel egg disks among shelves after a single point-release of T. deion. Results showed that T. deion parasitized more egg disks and killed more total eggs on open shelves than on gondola shelving. The presence of packaging had no effect on parasitoid foraging on open shelves; however, packaging did interfere with parasitism of P. interpunctella eggs on gondola shelving. Egg parasitism and mortality patterns among shelves were not as evenly distributed on gondola-type shelving compared with open shelving. On gondola shelves without packages, changing the release point of T. deion from the middle to the lowest shelf shifted the distribution of parasitism toward the floor. Gondola shelving, especially in the presence of packaging, reduced foraging efficiency of T. deion for P. interpunctella eggs. Thus, to attain adequate control of P. interpunctella, it may be necessary to use two release heights on gondola shelving.
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