105,728 research outputs found

    Yield determination in olive hedgerow orchards. II. Analysis of radiation and fruiting profiles

    Get PDF
    Profiles of fruit density, fruit size, and oil content were measured on 12 occasions in 7 olive orchards in Spain and 2 in Australia. Orchard structure varied widely. Height ranged from 2.0 to 5.5 m, row spacing from 3 to 6 m, and canopy width from 0.7 to 3m. Most orchards were oriented north–south (N–S) but one in Spain was oriented close to east–west (E–W)(208NE–SW). All orchards in Spain were cv. Arbequina, and in Australia they were cvv. Barnea and Picual. Analyses with a model of interception and transmission that estimated interception by individual sides of hedgerows revealed that fruit size and oil content were strongly related to intercepted radiation during the month before harvest across all orchards. Relationships were also evident between fruit density and interception but varied among orchards and years, indicating the importance of other environmental and probably physiological effects. In N–S orchards of cv. Arbequina, average fruit size and oil content increased linearly from 0.40 g (dry weight) to 0.72 g, and from 36 to 49% (of dry weight), as daily intercepted PAR increased from 6 to 25 mol/m2 (15–60% of horizontally incident radiation). The general principles of response extended to E–W orchards. There, it was shown that generally large fruit with high oil content on S sides was consistent with the plateau responses to radiation evident in the more extensive N–S data. On the N side, however, and accounting for transmission through the hedgerow, both fruit size and oil content were greater than in positions intercepting equivalent radiation inN–S orchards. Examples are provided of the utility of responses of fruit density, size, and oil content in establishing combinations of row height, row width, and row distance to improve or maintain productivity in some of the orchards included in the study

    Analysis of Flood Patterns in Adams County, Pennsylvania Utilizing Drone Technology and Computer Simulations

    Full text link
    Drone imagery and photogrammetry models of the Gettysburg College campus and the terrain at Boyer Nurseries and Orchards were utilized to study flood patterns in Adams County, Pennsylvania. Gettysburg College has lower-sloped land and moderately built infrastructure while Boyer Orchards has drastically sloped land with many patches of abundant vegetation. The two locations were selected due to the fact that they have starkly different surface features, while the bedrock geology of the areas are very similar. The terrain of the models was isolated before a 3D carver and 3D printer were used to construct physical models to further analyze potential water flow and speed through virtual, modeled flood simulations. The models were used to compare real world rainfall data and flood events in the investigated areas from the months of June to August in 2018. I hypothesized that the Gettysburg College campus would experience more severe flooding that would take longer to subside in comparison to Boyer Orchards due to the steeper slope of the orchards’ terrain. The research revealed that Boyer Orchards experienced more extreme flooding and rainfall than Gettysburg College but was able to neutralize the effects due to plentiful vegetation and physio-graphic differences. Modeled flood simulations demonstrated less rainfall in comparison to actual rainfall values: there were differences of 0.78 cm and 1.32 cm between the actual and simulated rainfall amounts for Gettysburg and the Boyer Orchards area, respectively

    Localization in orchards using Extended Kalman Filter for sensor-fusion - A FroboMind component

    Get PDF
    Making an automated vehicle navigate in rows of orchards is a feature, relevant for automating the plant nursing and cultivation of the trees. To be able to navigate accurate and reliably, the vehicle must know its position relative to the trees in the orchards

    Observations on the Biological Control Agents of the American Plum Borer (Lepidoptera: Pyralidae) In Michigan Cherry and Plum Orchards

    Get PDF
    The American plum borer, Euzophera semifuneralis (Walker) (Lepidoptera: Pyralidae), is an important pest in orchards, yet little is known regarding its biological control. We performed a comprehensive survey of the natural enemy complex contributing to American plum borer control in Michigan plum and cherry orchards, while also exploring the relationship between pest infestation and tree wounding from mechanical harvesting. We scouted 30 orchards with varying degrees of tree wounding to document extent of infestations of American plum borer and another pest, the lesser peach borer, Synanthedon pictipes (Grote and Robinson) (Lepidoptera: Sessiidae). We simultaneously recorded biological control agents, including the presence of a Hirsutella fungal pathogen. Live American plum borer larvae and pupae were collected for rearing and identifying hymenopteran parasitoids. American plum borer infestations were highest in orchards with high levels of tree wounding, or in orchards that used minimum pesticides or were abandoned. Numerous organisms were documented as biological control agents including various species of birds, spiders, beetles, and ants. Ichneumon wasps were the dominant parasitoids, of which Venturia nigricoxalis (Cushman) (Hymenoptera: Ichneumonidae) was the most common. Liotryphon variatipes (Provancher) (Hymenoptera: Ichneumonidae) was com- monly reared from a closely associated sessiid pest, but not from American plum borer. Hirsutella was commonly found and had a density-dependent relation- ship with American plum borer infestations. Our information gathered on the natural enemy complex of E. semifuneralis includes many new host associations and can serve as a starting point for developing biological control programs for fruit orchards in the Great Lakes region

    Dispersal of Rhagoletis cerasi in commercial cherry orchards: Efficacy of soil covering nets for cherry fruit fly control

    Get PDF
    Demand for organic cherries offers producers a premium price to improve their commercial viability. Organic standards require that producers find alternatives to pesticides. Soil treatments to control the European cherry fruit fly Rhagoletis cerasi (L.)(Diptera: Tephrididae) appear to be an attractive option. However, soil treatments can only be effective if the migration of flies is low, because mature flies may migrate from near-by trees for oviposition. To examine the general potential of soil treatments and to understand the dispersal and flight behaviour of R. cerasi within orchards, experiments using netting to cover the soil were conducted in two orchards with different pest pressure during two years. The netting reduced flight activity by 77% and fruit infestation by 91%. The data showed that the flies have a dispersal of less than 5 m within orchards, which is very low. The low thresholds for tolerance for infested fruit in the fresh market creates a strong economic incentive for control, therefore, soil covering is a promising strategy for controlling R. cerasi in commercial orchards

    Abundance and Identification of the Leafmining Guild on Apple in the Mid-Atlantic States

    Get PDF
    The leafmining guild on apple in the northeastern United States was studied from 1983 to 1988. Ten species of leafminers, all Lepidoptera, were encountered during the sampling. Phyllonorycter spp. (P. blancardella and P. crataegella) were the most ubiquitous and most abundant throughout the region. Lyonetia speculella was also abundant in both managed and unmanaged orchards, indicating a potential to become a pest. Bucculatrix pomiloliella and Coptodisca splendorilerella were abundant in unmanaged orchards, but were only rarely found in managed orchards. Coleophora serratella, Stigmella pomivorella, Parornix geminatella, Tischeria malifoliella, and Recurvaria nanella were also found. A key to the most important leafminer species on apple in the mid-Atlantic states, based on leafmine characteristics, is presented

    Understanding earwig phenology in top fruit orchards

    Get PDF
    Earwigs, Forficula auricularia, are key generalist predators to a variety of orchard pests. However, numbers of earwigs have declined in both organic and IPM orchards in recent years. Both Integrated and Organic fruit growers have tried to re-establish earwig populations, thus far with little success. To understand earwig population dynamics and to find measures to increase natural orchard populations, we conducted a detailed phenological survey of earwigs in orchards. Earwigs were sampled while sheltering during daytime in artificial refuges. They move into the trees from the third nymph stage onwards. In most orchards, a small second brood is produced in summer, and this has a positive impact on population size in fall. We see only minor differences in phenology between apple and pear orchards, mainly caused by differences in alternative hiding places. Earwigs show an inexplicable reduction in numbers at the timing of moulting into adults. When earwig phenology is correlated with pest phenology in apple and pear, its use for pest control of major pests is clear

    Field tests with Madex Plus against CpGV-resistant codling moth populations in organic orchards in 2006

    Get PDF
    When resistance to the Mexican isolate of Cydia pomonella Granulovirus (CpGV-M) arose in several organic orchards in Germany in 2004 and 2005, the future of codling moth control became a serious concern of organic fruit growing. In 2006, a new virus isolate from Andermatt Biocontrol AG (Madex Plus) was first tested in two field trials in organic orchards on codling moth populations resistant against the Mexican isolate of CpGV. Madex Plus showed a better efficacy on these populations than Madex 3. However, larval mortality larvae seemed to be somewhat delayed. A very good effect was shown in population control. The number of larvae in corrugated card board belts was significantly reduced after treatment with Madex Plus. In addition to these trials, on-farm trials in all orchards concerned of the CpGV-M resistance were carried out. The results of on-farm trials showed the same tendency: high efficacy in population control against a background of slightly delayed larval death. In 2007, Madex Plus was applied successfully in all organic orchards with CpGV-M-resistant codling moth populations in Germany

    Funkcionālās agrobioloÄŁiskās daudzveidÄ«bas pasākumu novērtēơanas metodes ābeÄŒu dārzos Latvijā

    Get PDF
    Overview about methods to evaluate functional agrobiodiversity in apple orchards in Latvia

    A survey of natural parasitism of mirid bugs by parasitoids on apples and pears in Norway

    Get PDF
    Mirid bugs are important pests in both integrated and organic fruit production. In a survey in 2006 the proportion of mirids parasitized by parasitoids was investigated in 18 Norwegian orchards. More than 50 beating samples were collected from apple and pear orchards under integrated and organic management in different areas of Norway. About 30% of nymphs of the most abundant mirid bug species, Lygocoris pabulinus, Ortholylus marginalis and Psallus ambiguus, were parasitized. Important factors for enhancing biological control in organic fruit production are discussed
    • 

    corecore