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1.
Abstract: We evaluated three different deployment patterns of sticky red sphere traps, baited with a five-component blend of synthetic attractive fruit odour and placed on perimeter apple trees bordering adjacent habitat (front-row trees), for control of apple maggot flies, Rhagoletis pomonella (Walsh), in small plots of apple trees (about 30 × 30 m) in Massachusetts commercial apple orchards. Degree of fly penetration from front-row to interior apple trees was assessed for R. pomonella of wild origin and for marked adults released in habitats adjacent to front-row trees. Traps placed 10  and 5 m apart on front-row trees or grouped on a single central front-row tree performed as well as grower-applied insecticide sprays in preventing penetration of plots by wild and released flies and in preventing fruit injury . This was equally true for plots whose front-row trees consisted of cultivars comparatively susceptible to apple maggot as for plots whose front-row trees were comprised of comparatively tolerant cultivars. It was also true for each seasonal period during which sampling for treatment performance occurred.  相似文献   

2.
Host specificity tests carried out in the laboratory in Australia during 1977, showed thatMicrothrix inconspicuella Ragonot could develop on young apple leaves (Harley et al., 1979). Field studies in unsprayed apple orchards in South Africa showed that some feeding occurred, but fewer than 40% of late instar larvae developed to adults when confined in sleeves on apple tree branches. No feeding or survival occurred in large field cages or in the open. Adults which developed from apple fed larvae were smaller, deformed, occasionally mated and laid fertile eggs but their progeny did not feed or develop on apple fruit or leaves. In conclusion,M. inconspicuella larvae did not develop on apple fruit or leaves in the field, damage was mainly limited to apples already injured and feeding on leaves was minimal. Under normal pest control practicesM. inconspicuella populations did not survive on any part of the apple tree or onE. australis growing under the trees.   相似文献   

3.
The plum curculio, Conotrachelus nenuphar (Herbst), is a key pest of pome and stone fruit in eastern and central North America. For effective management of this insect pest in commercial apple (Malus spp.) orchards in the northeastern United States and Canada, one of the greatest challenges has been to determine the need for and timing of insecticide applications that will protect apple fruit from injury by adults. In a 2004-2005 study, we assessed the efficacy and economic viability of a reduced-risk integrated pest management strategy involving an odor-baited trap tree approach to determine need for and timing of insecticide use against plum curculio based on appearance of fresh egg-laying scars. Evaluations took place in commercial apple orchards in seven northeastern U.S. states. More specifically, we compared the trap-tree approach with three calendar-driven whole-block sprays and with heat-unit accumulation models that predict how long insecticide should be applied to orchard trees to prevent injury by plum curculio late in the season. Trap tree plots received a whole-plot insecticide spray by the time of petal fall, and succeeding sprays (if needed) were applied to peripheral-row trees only, depending on a threshold of one fresh plum curculio egg-laying scar out of 25 fruit sampled from a single trap tree. In both years, level of plum curculio injury to fruit sampled from perimeter-row, the most interior-row trees and whole-plot injury in trap tree plots did not differ significantly from that recorded in plots subject to conventional management or in plots managed using the heat-unit accumulation approach. The amount of insecticide used in trap tree plots was reduced at least by 43% compared with plots managed with the conventional approach. Advantages and potential pitfalls of the bio-based trap tree approach to plum curculio monitoring in apple orchards are discussed.  相似文献   

4.
The knowledge and conservation of diminishing valuable habitats in agricultural landscapes are of key importance in saving declining farmland biodiversity. One of these habitats is the traditional orchard whose role in supporting birds is still poorly known, especially in winter. We counted birds in 106 orchards differing in management intensity (abandoned, traditional, and intensive) during December 2009 and January 2010 in Wielkopolska, western Poland and measured site characteristics and composition of surrounding landscapes for every orchard. Old abandoned and traditionally managed orchards had significantly higher bird species richness than intensive ones. Irrespective of orchard type, bird species richness as well as density were positively influenced by the cover of unmown herb layer in orchards and tree diversity. Tree and fruit densities positively affected bird species richness and density mainly in abandoned orchards while in other orchard types the effect of these variables was less pronounced. Land cover diversity in a landscape had a positive effect on species richness and density mostly in abandoned orchards and we believe that this effect reflects the elevated utilization of such orchards by birds from the surrounding landscape. Thus, abandoned, as well as traditionally managed orchards seems to be especially important habitats that offer food source and refuge for wintering birds and should be protected. We propose to diversify fruit production by planting various tree species, leaving part of the herb layer unmown and several trees unharvested in intensive orchards in order to improve suitability of modern orchards for birds.  相似文献   

5.
黄土高原苹果园土壤水分及水分生产力模拟   总被引:1,自引:0,他引:1  
以长武地区为例,采用WinEPIC模型模拟1980—2018年间黄土高原旱作苹果园地深剖面土壤水分和水分生产力变化动态,以期为该区苹果产业的可持续发展提供科学依据。结果表明: 长武地区苹果园年均产量为26.37 t·hm-2,年均蒸散量为673.66 mm,年均水分生产力为4.07 kg·m-3,成龄果树水分胁迫天数主要受降雨量影响,果树生长后期年均胁迫天数为46.46 d,深层土壤含水量最早于9龄果树开始接近凋萎湿度。长武地区苹果整个生长周期内供水量是对果园产量影响最大的因素,深层土壤有效水含量降低是制约果树生长中后期产量提高的最主要因素,在降水不足的年份果树会利用更深层土壤水分。当深层土壤可利用水分较少时,过多的降水并未被果树利用,而是转化为浅层土壤水分蒸发。对于成龄果树在年供水量低于500 mm或高于700 mm时都会造成产量的下降。针对不同生长时期的果园,在不同的降雨年份应该调整果园水分管理策略,可以通过补充灌溉、拦蓄集聚雨水、覆盖、修剪枝条等管理措施,降低果树非生产性耗水及自身奢侈性耗水,延缓深层土壤干层的出现时间,在保证果树生长的同时避免水资源的浪费。  相似文献   

6.
We compared a trap approach with a trap-tree approach to determine the need and timing of insecticide applications against overwintered adult plum curculios, Conotrachelus nenuphar (Herbst.), in commercial apple orchards in Massachusetts in 2002. All traps and trap trees were baited with benzaldehyde (attractive fruit odor) plus grandisoic acid (attractive pheromone). Sticky clear Plexiglas panel traps placed at orchard borders, designed to intercept adults immigrating from border areas by flight, captured significantly more adults than similarly placed black pyramid traps, which are designed to capture adults immigrating primarily by crawling, or Circle traps wrapped around trunks of perimeter-row trees, which are designed to intercept adults crawling up tree trunks. None of these trap types, however, exhibited amounts of captures that correlated significantly with either weekly or season-long amounts of fresh ovipositional injury to fruit by adults. Hence, none appears to offer high promise as a tool for effectively monitoring the seasonal course of plum curculio injury to apples in commercial orchards in Massachusetts. In contrast, baiting branches of selected perimeter-row trees with benzaldehyde plus grandisoic acid led to significant aggregation (14-15-fold) of ovipositional injury, markedly facilitating monitoring of the seasonal course of injury to apples. A concurrent experiment revealed that addition of other synthetic fruit odor attractants to apple trees baited with benzaldehyde plus grandisoic acid did not enhance aggregation of ovipositional injury above that of this dual combination. We conclude that monitoring apples on odor-baited trap trees for fresh ovipositional injury could be a useful new approach for determining need and timing of insecticide application against plum curculio in commercial orchards.  相似文献   

7.
The effects of different levels of Fe-deficiency chlorosis on the fruit yield, appearance and composition of pear and peach trees grown in field orchards have been studied. The major effect of Fe deficiency in both species was a large yield reduction, even when chlorosis was moderate, associated to decreases in fruit tree load. Fruit size increased with moderate chlorosis in both species and decreased with severe chlorosis in peach. In peach, moderate or severe chlorosis affected uniformly all branches, leading to firmer fruits with higher acidity, total phenolics and carboxylates. This indicates a delayed maturity that can be attributed to a low C-availability for fruits. In Fe-deficient pear trees, the majority of fruits (98%) were on non-chlorotic or moderately chlorotic branches, and fruits were less green and firm with an increased sugars/acids ratio. This indicates an advanced fruit maturity that can be attributed to an increased C-availability for fruits. All chlorosis levels increased within-tree variation in fruit appearance.  相似文献   

8.
不同栽培管理梨园梨小食心虫发生程度研究   总被引:2,自引:1,他引:2  
梨小食心虫Grapholitha molesta(Busck)是梨园中的一种重要害虫。本论文采用性诱剂诱集法研究了不同栽培管理条件下梨园梨小食心虫发生的情况。结果表明,在5种不同种植模式的果园中,梨小食心虫在单植桃园中发生最重,试验期间梨小食心虫的日平均诱蛾量为10.9头/盆,与其他4种栽植模式果园的诱捕量均呈显著差异,且混有桃树的果园中梨小食心虫的发生数量多,而单植梨园、梨苹果混栽园、单植苹果园的梨小食心虫发生相对较轻。果实套袋的管理方法也可以显著降低梨小食心虫的发生数量,非套袋梨园的日平均诱捕量为13.8头/盆,是套袋梨园的1.52倍。试验还表明,不同品种和不同树龄的梨树对梨小食心虫的抗虫性均存在显著差异。酥梨比巴梨的抗虫性差,试验期间酥梨园的日平均诱捕量为12.6头/盆,是巴梨园的2.21倍,而40年老酥梨园日平均诱蛾量为12.5头/盆,是20年酥梨园诱蛾量的2.5倍。  相似文献   

9.
为研究间伐改形对红富士成龄乔化密植果园树体冠层特征、生育后期叶片生理特性、养分积累分配规律、光合生产力和土壤水分时空分布动态的影响,以18年生‘红富士’苹果密闭园为试材,对苹果树单株结构参数、枝量、枝类组成、覆盖率、叶片光合速率等参数进行测定.结果表明: 密闭果园叶片光合作用受非气孔因素限制,导致PSII最大光化学效率、PSII光合潜能、光合性能指数下降了1.2%、11.5%、13.9%.间伐改形后,叶面积指数、树冠覆盖率有所降低,使得冠层直射光透过系数增加了79.0%,树形结构有所改善.苹果园总枝数降低到约1100400条·hm-2,单株枝量增加了5.0%,短枝比例提高至73.0%.由于冠层光照条件的改善,叶面积、比叶质量、百叶重、叶绿素含量有不同程度的提高.叶片光合速率的提高促进了光合产物的积累,淀粉、蛋白质含量为密闭果园的143.5%、107.8%.叶片的发育质量与其所处的光照辐射环境有着密切联系,密闭果园经间伐、改形后,果园群体结构和冠层光照得以改善,促进了叶片生长发育,提高了叶片光合效能,降低了果园土壤水分的无效消耗,是陇东旱塬苹果产区密闭果园适宜的调整、优化方案.  相似文献   

10.
Plant architecture of apple trees in commercial orchards was rapidly changed from traditional tall trees to dwarf trees to optimize yield and fruit quality. Additionally, hail nets are widely used to prevent yield loss by hail. These changes are expected to considerably influence the orchard microclimate and thus the developmental rates of pest insects in apple. However, these relationships have not yet been fully elucidated. The present study was conducted over the seasonal cycle to investigate the influence of plant architecture and hail nets on the habitat temperatures of the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), in apple, Malus domestica Borkh. (Rosaceae). Within the canopies, leaf area index (LAI) and global site factor (GSF) were quantified using hemispherical photography. Temperature was analysed for the main habitats of the different codling moth stages, i.e., air within the canopy, bark of tree stems, and apple fruit. In dwarf trees, LAI was lower, leading to a higher GSF than in tall trees. Hail nets did not influence LAI and GSF. Results for dwarf trees compare as follows with those for tall trees: Average air temperatures within the canopy were 0.7 °C higher during daytime, whereas 0.4 °C lower at night. Mean surface temperatures of bark were 0.9 °C higher on sunny and 0.4 °C on overcast days. Mean surface temperatures of apple fruits were 1.8–2.7 °C higher on sunny days, but 0.6 °C cooler on overcast days. The effect of hail nets was confined to a reduction of the air temperature within the canopy by approximately 0.2–0.8 °C. Bark and apple surface temperatures were not significantly affected. Based on the temperature differences in the habitats considered, the calculated development of the codling moth in dwarf trees was on average 3 days faster than in tall trees. The calculations imply a negligible effect of hail nets on codling moth development.  相似文献   

11.
Winter tree pruning is a cultural practice known to modify vegetative growth, which is likely to affect the development of pests. However, it has been poorly addressed as a cultural control method for diminishing the population levels of the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae), in peach [ Prunus persica (L.) Batsch (Rosaceae)] orchards. In this study, we conducted a 2-year, on-station experiment to evaluate how winter pruning affects peach– M. persicae interactions, by examining tree vegetative growth, aphid population dynamics, and crop yield and fruit quality. We collected data under an insect-proof shelter on adult peach trees submitted to various levels of pruning and artificially infested with aphids. Our results showed that pruning enhanced shoot growth due to the proportion of growing shoots, which increased exponentially (10–60%), whereas the growth rate of growing shoots was not affected. The degree of infestation of peach trees increased with increasing pruning intensity. This effect was mainly due to the increase of the proportion of growing shoots, on which aphids developed better than on rosettes. In turn, the higher the aphid infestation, the higher the aphid-induced shoot-tip damage, leaf curling, and leaf fall that disturbed the growth of growing shoots. However, aphids did not considerably reduce fruit quality at harvest. They did not affect fresh fruit weight, and the refractometric index (indicator of sugar content) was reduced by only 3–4%. The relevance of winter pruning as a cultural method for pest control in orchards conducted under integrated fruit production guidelines is discussed.  相似文献   

12.
The apple maggot, Rhagoletis pomonella (Walsh), was monitored with baited yellow panels and red spheres in commercial orchards, abandoned orchards, and unsprayed backyard apple trees in 1998 and 1999. Apple maggot adults were captured in all apple habitats, but the capture levels in the abandoned orchards and unsprayed backyard trees tended to be higher than in the commercial orchards. Peak capture occurred between mid-July and late August in both years. Emergence cages seeded with infested fruits were used to investigate bivoltinism, which was observed in both years.  相似文献   

13.
Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV) and Apple mosaic virus are economically important viruses infecting fruit tree species worldwide. To evaluate the occurrence of these pome fruit viruses in Latvia, a large‐scale survey was carried out in 2007. Collected samples were tested for infection by DAS ELISA and multiplex RT‐PCR. The accuracy of the detection of the viruses in multiplex RT‐PCR was confirmed by sequencing amplified PCR fragments. The results showed a wide occurrence of viruses in apple and pear commercial orchards established from non‐tested planting material. More than 89% of the tested apple trees and more than 60% of pear trees were infected with one or more pome fruit viruses. Analyses showed that the high occurrence of viruses in several apple cultivars is due to the propagation of infected clonal rootstocks and scions from infected mother trees. Sequence analyses targeting the 3′‐terminal region of the tested viruses showed various degrees of genetic diversity within respective virus isolates. This is the first report of the occurrence of ACLSV, ASGV and ASPV in apple and pear trees in Latvia and demonstrates their genetic diversity in different host genotypes.  相似文献   

14.
洛川苹果园土壤水分变化特征   总被引:7,自引:0,他引:7  
全面掌握洛川果园的土壤水分环境特征,不仅可为苹果的园址选择、砧穗组合和改进土壤水分管理措施提供理论依据,而且对我国苹果产区果园提质增效具有借鉴价值.采用定点土壤水分连续监测法,对洛川苹果园的总体土壤水分环境以及不同生长年限、不同立地类型和乔、矮化果园的土壤水分分异特征进行分析.结果表明: 苹果树根际区 (0~200 cm)土壤水分普遍亏欠,且0~60 cm土层的水分亏欠小于60~200 cm土层;生长季0~60 cm土层贮水量与降水量的变化一致,土壤相对含水量大多<60%,季节性旱象严重;果园剖面土壤含水量变异系数随土壤深度加深而递减;随果园生长年限的增大,土壤剖面贮水量下降;在栽培密度一致的条件下,矮化果园5 m土层土壤含水量均高于乔化果园,而栽培密度大的矮化果园的土壤贮水量低于栽培密度小的乔化果园;塬地成龄果园的土壤水分含量最高,川地次之,台地相对较低.密度对果园土壤水分含量有很大影响,在栽培密度一致的条件下,采用矮化栽培能减少土壤水分消耗,显著提高果园土壤含水量;挖株降低栽培密度是维持苹果园土壤水分平衡、实现可持续发展的有效途径.  相似文献   

15.
Because of the potentially serious damage rosy apple aphid, Dysaphis plantaginea (Passerini) (Homoptera: Aphididae), can cause to apple fruit and branch development, prophylactic insecticides are often used for control. If biological control could be relied on, the amount of pesticide applied in orchards could be reduced. This study examined biological control of rosy apple aphid in eastern West Virginia and the potential for enhancement through conservation biological control, in particular, the effect of interplanting extrafloral nectar-bearing peach trees. By 20 d after first bloom, only 2% of fundatrices initially present survived to form colonies based on regression of data from 687 colonies. Exclusion studies showed that many of the early colonies were probably destroyed by predation; the major predator responsible seemed to be adult Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). Mortality before apple bloom was most important in controlling rosy apple aphid population growth but by itself is not sufficiently reliable to prevent economic injury. Interplanting of extrafloral nectar-bearing trees did not increase biological control, and interplanting with 50% trees with extrafloral nectar glands reduced biological control. The number of leaf curl colonies in the 50% interplanted orchards was lower than in monoculture orchards, suggesting a preference of alate oviparae for more diverse habitats, supporting the resource concentration hypothesis but not at a level sufficient to prevent injury. Predation and parasitism after the formation of leaf curl colonies was not adequate to control rosy apple aphid populations.  相似文献   

16.
Studies were conducted in 1997 and 1998 to evaluate the effects of three particle film formulations consisting of kaolin and adjuvants on neonate larvae, ovipositing adult females, and eggs of the codling moth, Cydia pomonella (L.). Neonate larval walking speed, fruit discovery rate, and fruit penetration rate on apple host plants coated with particle films were significantly lower than on host plants without particle films in laboratory assays. Females oviposited less on host plants covered with a particle film residue than on untreated plants in laboratory choice and no-choice tests. Hatch rate of codling moth neonate larvae was unaffected by particle films sprayed on host plants either before or after oviposition. Fruit infestation rates were significantly reduced on particle film-treated trees compared with untreated trees for both first- and second-generation codling moth in field trials in both apple and pear orchards. Particle films appear to be a promising supplemental control approach for codling moth in orchards where moth density is high, and may represent a stand-alone method where moth densities are lower.  相似文献   

17.
In commercial orchards in Massachusetts in 2003, we conducted experiments aimed at developing guidelines for use of perimeter-row trap trees baited with grandisoic acid plus benzaldehyde as sentinels in a practical approach to determining need and timing of insecticide applications against overwintered plum curculios, Conotrachelus nenuphar (Herbst). Evaluations were based on percentages of sampled fruit injured by plum curculio. Trap trees baited with grandisoic acid released at approximately 1 mg/d plus benzaldehyde released at approximately 40 mg/d performed as well as or better than trap trees baited with greater or lesser amounts of these attractants in combination. The distance over which a trap tree baited with such odor was effective in aggregating damage to fruit extended to at least 31-33 m (maximum evaluated) along a perimeter row. Trap trees at corners of orchard blocks were as effective as perimeter-row trap trees midway between corner trees. Within the canopy of a trap tree, damage did not tend significantly to be localized in the vicinity of the odor source but tended to be rather evenly distributed among various sectors of the canopy. Finally, among three candidate thresholds evaluated as a trigger for insecticide application, a threshold of one freshly injured fruit proved better than thresholds of two or four freshly injured fruit out of 50 fruit sampled on a trap tree in assuring that orchard-wide damage would remain below a preset economic injury level of 1%. Our findings lead us to suggest that after a whole-orchard application of insecticide to apple trees in Massachusetts orchards shortly after petal fall, subsequent applications of insecticide against plum curculio can be confined to peripheral-row trees and be driven by a provisional threshold of one freshly injured fruit out of 50 fruit sampled on a perimeter-row trap tree baited with the above-mentioned odor.  相似文献   

18.
Over a 3-year period (1997–1999), we examined the influence of tree size on effectiveness of traps for behaviourally controlling apple maggot flies, Rhagoletis pomonella (Walsh), in small blocks of trees in Massachusetts commercial apple orchards. Traps were red spheres coated with Tangletrap and baited with an attractive synthetic host fruit odour (butyl hexanoate). Traps were placed 6 m apart on perimeter apple trees of each block and were designed to intercept apple maggot flies immigrating into blocks from unmanaged host trees. Based on captures of adults by unbaited red spheres placed near the centre of each block to monitor degree of adult penetration into the interior and on percentages of fruit injured by apple maggot, traps surrounding blocks of small trees (1.5 m canopy diameter) planted at high density were more effective in controlling apple maggot flies (relative to control obtained by insecticide sprays used in comparison blocks) than were traps surrounding blocks of large trees (3.7 m canopy diameter) planted at low density, with traps surrounding blocks of medium-size trees (2.5 m canopy diameter) planted at medium density generally providing an intermediate level of control.  相似文献   

19.
Biocontrol using naturally occurring predators is often limited by population parameters of those predators. Earwigs, Forficula auricularia L. (Dermaptera: Forficulidae), are important predators in fruit orchards. They are capable of suppressing outbreaks of pest species, such as pear psyllid and various apple aphid species. Earwigs therefore play an important role in integrated pest management in fruit orchards and are essential in organic top fruit cultures. However, earwig populations are very unstable, showing large between-year variation in densities, which limits their practical use. Extensive knowledge of regulating processes of populations is therefore crucial for efficient orchard management. A 2-year phenological study in several apple and pear orchards in Belgium showed a significant displacement of third instars during the second brood in relation to the presence of adults. We also observed a yearly population crash at the time of moulting into adults. This population decrease was correlated with earwig numbers at peak density. The crash occurred at lower earwig densities in apple orchards than in pear orchards. Six possible regulating mechanisms for this density-dependent decrease are discussed: (1) migration, (2) pesticides or orchard management, (3) starvation, (4) pathogens, (5) parasites and parasitoids, and (6) predation or cannibalism. If we can identify these regulating processes, specific management activities could be developed to prevent the population crash, hereby increasing population densities in the orchards.  相似文献   

20.
One of the five most important global biodiversity hotspots, the Neotropical Atlantic forest supports a diverse community of birds that nest in tree cavities. Cavity‐nesting birds may be particularly sensitive to forestry and agricultural practices that remove potential nest trees; however, there have been few efforts to determine what constitutes a potential nest tree in Neotropical forests. We aimed to determine the characteristics of trees and cavities used in nesting by excavators (species that excavate their own nest cavity) and secondary cavity‐nesters (species that rely on existing cavities), and to identify the characteristics of trees most likely to contain suitable cavities in the Atlantic forest of Argentina. We used univariate analyses and conditional logistic regression models to compare characteristics of nest trees paired with unused trees found over three breeding seasons (2006–2008). Excavators selected dead or unhealthy trees. Secondary cavity‐nesters primarily selected cavities that were deep and high on the tree, using live and dead cavity‐bearing trees in proportion to their availability. Nonexcavated cavities suitable for birds occurred primarily in live trees. They were most likely to develop in large‐diameter trees, especially grapia Apuleia leiocarpa and trees in co‐dominant or suppressed crown classes. To conserve cavity‐nesting birds of the Atlantic forest, we recommend a combination of policies, economic assistance, environmental education, and technical support for forest managers and small‐scale farmers, to maintain large healthy and unhealthy trees in commercial logging operations and on farms.  相似文献   

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