Versuche zur Regulierung des Birnenblattsaugers

European pear sucker causes financial penalties in many pear orchards. Honey dew exudations reduce qual-ity. Another problem is the transmission of pear decline. In years of high infestation chemical treatments are complicated. Neither cutisan- nor sugar-treatments showed an appreciable reduction of the pest in the year 2005

Trials to control European pear sucker

European pear sucker causes financial penalties in many pear orchards. Honey dew exudations reduce quality. Another problem is the transmission of pear decline. In years of high infestation chemical treatments are complicated. Neither cutisan- nor sugar-treatments showed an appreciable reduction of the pest in the year 2005

SEASONAL OLIGOPOLY POWER IN THE D'ANJOU PEAR INDUSTRY

We estimate seasonal oligopoly power at a disaggregated variety level in the D'Anjou pear market. Our data spans 1993 to 2000, during which time imported pears became more prevalent in the U.S. market. The range of monthly industry-conduct-parameter magnitudes is 0.034 to 0.195 and is most pronounced when the fresh D'Anjou pear crop first becomes available in the earliest months of the marketing year. Possible reasons for timing of oligopoly power relate to the growth of imported pears during the latter portion of marketing year. In addition, oligopoly power may diminish during the marketing year as pears in storage decline in quality.Crop Production/Industries,

High-efficiency texture coding and synthesis on point-based pear surface

© 2017 IOS Press and the authors. The fruit images on points cloud acquired by the current 3D scanner from field will appear a visible seams, inconvenient data acquisition or taking large space due to unorganized background. We give a SAOW method to cope with the space efficiency and realistic effects of texture synthesis on pear point model. At first, a point-quadtree is proposed to simplify the pear image division. Then, an adaptive multi-granularity morton coding scheme are presented to optimizing the memory space of pear image. At last, weighted oversampling mixing method is mainly focused on texture quality of pear surface. As shown in the experiment results, our adaptive division makes the memory space decline dramatically about 90.7% than non-division and 92.9% than general division respectively; adaptive code scheme helps to reduce the memory to 72.1% of ordinary morton code; weighted oversampling keeps the mixed texture more real and smoothly than current methods

Populations of Pear Thrips, \u3ci\u3eTaeniothrips Inconsequens\u3c/i\u3e (Thysanoptera: Thripidae) in Sugar Maple Stands in Vermont: 1989-2005

Development of an effective IPM strategy for pear thrips, Taeniothrips inconsequens (Uzel) (Thysanoptera: Thripidae), a pest of sugar maple, Acer saccharum Marshall, demands an understanding of their population fluctuations over time. Pear thrips populations were monitored using a standardized soil sampling method every fall from 1989 – 2005 in 14 counties of Vermont (U.S.). Data from individual sites were combined into north, central and south regions. High numbers of thrips emerged from soil sampled in 1989, 1990, 1993 and 2001, particularly in the north region (Washington, Lamoille, and Franklin counties). The central and south regions had lower pear thrips populations over all years. These results provide, for the first time, fundamental knowledge of pear thrips populations across a wide geographical area of Vermont and will assist in the design of suitable control strategies for pear thrips in the future

Influence of macroalgal cover on coral colony growth rates on fringing reefs of Discovery Bay, Jamaica: a letter report

This study investigated the hypothesis that alterations in macroalgal cover significantly influenced the growth rates of coral colonies on the fringing reefs of Discovery Bay, Jamaica. For colonies of Montastrea annularis, Porites astreoides, and Sidastrea siderea, radial growth rates were significantly (p<0.02) higher at Dairy Bull (where Diadema antillarum had removed macroalgal cover) than at either M1 or Rio Bueno (where there was c. 80% macroalgal cover). For colonies of Colpophyllia natans and Montastrea fankseii, radial growth rates were significantly (p<0.02) higher at Dairy Bull than at Rio Bueno. It has been suggested that macroalgal shading as well as contact is a significant inhibitor of coral growth, and our results are in accord with that hypothesis. These studies suggest that marine park managers should foster macroalgal predation wherever possible, in order to limit the irreversible decline of coral reefs

Understanding earwig phenology in top fruit orchards

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

Identification and quantification of ‘Candidatus Phytoplasma pyri’ in declining trees of a Swiss cider pear orchard after incision treatment at the stem base

Candidatus Orchards of 30 to >100 years old fruit trees used for cider production are endangered by an accumulation of abiotic and biotic stress factors. Among biotic stress factors, diseases such as pear decline (PD) caused by the bacterial pathogen ' Phytoplasma ' contributes to a weakening and reduced life time of affected trees. Since direct treatment of this disease is not possible, approaches have gained attention, which might lead to an increased resilience against this pathogen, such as incisions of the cambium at the graft union at the stem base. Six 35 years old pear trees () of a Swiss cider production orchard, all affected by mild decline were chosen for this study. Four out of them were treated with 2-4 incisions per tree in February 2016. Symptoms were visually assessed during summer and autumn 2016 and 2017, respectively, and ' P ' measured in branch samples with a newly developed duplex TaqMan qPCR assay. No effect could be determined within these two subsequent growing seasons after treatment. Both, visual assessment of symptoms and qPCR measurement of the pathogen in branches did not show any difference between treated and untreated trees. The sequencing of two marker genes of the pathogen detected in this orchard confirmed its identity as ' ' and revealed that it belongs to the major genotype present in Europe

Effectiveness of entomopathogenic nematodes in the control of Cydia pomonella larvae in Northern Italy

Since 2006, a large scale research on the effectiveness of entomopathogenic nematodes (EPN) in the control of codling moth (CM), Cydia pomonella, overwintering larvae has been performed on about 35 ha of pear orchards per year in Emilia-Romagna, Northern Italy. Steinernema carpocapsae and Steinernema feltiae activity was checked after spray applications of EPNs to the trunk and branches. In 2006, the treatment was applied either in spring or in autumn at different doses, before CM pupation; in 2007 the EPN treatment was applied only in autumn at 1.5 x 109 I.J. ha –1. Every year it was distributed by means of a conventional mist blower. The larval mortality was assessed directly on sentinel larvae in card boards on the trunks and indirectly on the eggs laid by the females of the first CM generation in spring. Moreover, each year, a trial was performed applying only S. carpocapsae on sentinel larvae with the aim of testing this nematode at suitable temperatures but at different water volumes. The CM sentinel larvae were effectively parasitized after autumnal EPN application. Moreover, the egg assessment demonstrated a good decrease in CM population in spring 2007, when EPNs had been applied at the best weather conditions (t° 12-14 °C and rain) in the previous autumn