Screening preharvest/postharvest strategies to prevent fruit rot decay

In fruit growing preharvest sprayings in the orchard are mainly applied to protect fruit from decaying. Next to multisite fungicides (captan, thiram, tolylfluanid) the most commonly used products recognized for the Belgium market are Bellis (pyraclostrobin & boscalid) and the combination of Topsin M (thiophanate-methyl) and Frugico (diethofencarb). In general the spraying schedule varies depending on weather conditions (infection risk), preharvest interval of available fungicides, fruitgrower and cultivar of pome fruit (apple/pear). Facing the climatological conditions before picking the residue loading on the fruit surface can differ enormously. Also wet (pre)grading is considered to decrease the product residue resulting to fruits which are less protected before entering the cold storage room. In this context a partially replacement of the preharvest treatments by one postharvest application could offer a reliable alternative to the PPP reduction program (Plant Protection Products) in the orchard. A standardized application method by dipping or drenching will cover the fruits homogenically resulting in a rationalized fungicide use compared to the preharvest sprayings in the orchard. For the Belgium market Philabuster (imazalil & pyrimethanil) is registered for postharvest treatments since for this product a proper solution for the waste water of postharvest uses was developed to protect surface waters (Funds technology). Philabuster provides an advanced mould control towards fruit rot pathogens Gloeosporium spp., Botrytis cinerea and Penicillium spp. In this context several trials were set up to evaluate the biological efficacy of Philabuster alone or in combination with preharvest sprayings in the orchard. In concrete different preharvest spraying schedules were applied in the last six weeks before harvest on apple and pear facing parameters as rational fungicide use, antifungal effectiveness and cost price. The purpose was to select the optimal combination in use of preharvest fungicides with Philabuster as postharvest treatment, which offer full protection towards all key pathogens in apple and pear.     

Summer Epidemics of Apple Scab: The Relationship between Measurements and their Implications for the Development of Predictive Models and Threshold Levels under Different Disease Control Regimes

A 2‐year study on epidemic progress of apple scab was conducted at Randwijk, the Netherlands, in 1998 and 1999. The summer epidemic caused by conidia was studied instead of the well‐described spring season epidemic originating from ascospores. The aim was to investigate relationships between disease measurements, i.e. disease incidence and severity measures of apple scab, and their implications for the development of predictive models and threshold levels. The study characterized good relationships between the measurements on cultivar Jonagold using regression analyses in three disease control regimes (untreated, organic and integrated). For fruit quality prediction, the relationship between fruit incidence (I_f) and leaf incidence (I_l) in the organic control regime was given by I_f = 1.966 + 0.402 × (I_l) (R² = 0.92). As a result of low level of disease in the integrated control regime, shoot incidence (I_s), with higher values than leaf incidence, was better suited for prediction. The relationship was given by I_f = ?0.162 + 0.028 × (I_s) (R² = 0.91). For the integrated control regime, disease threshold levels were constructed for timing of the final fungicide application. If an apple grower wants to keep fruit infection under 1% incidence (harvest scab threshold), the timing of the final fungicide application (action threshold) should correspond to 4% shoot scab incidence at the beginning of August. The results are compared with similar studies and their biological interpretation is discussed.     

Evaluation of the Use of Ammonium Bicarbonate and Oregano (Origanum vulgare ssp. hirtum) Extract on the Control of Apple Scab

In vitro experiments showed that ammonium bicarbonate and aqueous extracts of oregano were effective in inhibiting conidia germination and germ‐tube elongation of Venturia inaequalis. Complete inhibition was achieved by 1% ammonium bicarbonate, 2% oregano extract and 0.01% synthetic fungicide difenoconazole. Two orchard experiments were conducted on the highly susceptible cv. Mutsu to apple scab to investigate the efficacy of ammonium bicarbonate alone or in combination with an aqueous extract of oregano for the control of apple scab. In 2008 and 2009, except for the applications of 1% aqueous extract of oregano, the applications of ammonium bicarbonate (0.5 and 1%) and difenoconazole (0.01%) to trees at 10‐day intervals significantly reduced disease incidence and severity on leaves and fruit compared to the water‐treated control. In both years, the efficacy of 0.5 and 1% ammonium bicarbonate in inhibiting both disease incidence and severity on leaves and fruit was equally effective in all monthly assessments from June to September. Combining 0.5 and 1% ammonium bicarbonate with 1% aqueous extract of oregano did not significantly improve the efficacy of stand‐alone applications of treatments in the final assessment in 2008 and 2009. All treatments were neither phytotoxic to leaves and fruit nor did they adversely affect quality parameters of fruit including physiological disorders and taste both at harvest and after storage. These results indicate that ammonium bicarbonate treatment may be applied as an alternative chemical for the control of apple scab.     

The suppression of Phytophthora syringae in orchard soil by furalaxyl as a means of controlling fruit rot of apple and pear

Apple orchard soil treated with Aaterra (etridiazole), A5430 (furalaxyl), copper sulphate, LS 74–783 (aluminium tris(ethyl phosphonate)) or water in mid-August 1977 was assayed for Phytophthora syringae by an apple fruit baiting method immediately after fungicide application and at weekly intervals for 8 wk. There was no infection of baits placed in the orchard and this was attributed to low rainfall. When wetted and baited, samples of surface soil caused from 0 to 85% fruit infection depending on the time of sampling and soil treatment. In control soil, fungus activity was low in the first 4 wk, high in the fifth wk and fluctuated widely thereafter. In samples from soils treated with Aaterra, copper sulphate or LS 74–783 activity was first apparent in the fifth wk and then fluctuated roughly in parallel with that of control soil although at generally lower levels. Changing levels of activity were apparently related to air temperature during baiting. No infection of fruits occurred in any samples from soil treated with furalaxyl. Further assays of this soil indicated a complete suppression of P. syringae to at least 10 cm soil depth. Furalaxyl is sufficiently active to be considered as a soil treatment for controlling Phytophthora fruit rot of apple and pear.     

果实种类及发育阶段对梨小食心虫幼虫钻蛀率和蛹重的影响

【目的】明确梨小食心虫Grapholitha molesta在寄主果实上的钻蛀率和蛹重与寄主种类和果实发育阶段的关系,为其田间预测预报和综合防控提供技术依据。【方法】在室内条件下测定了接卵后72 h梨小食心虫初孵幼虫在不同发育阶段的3个种共6个品种水果［苹果Malus pumila (嘎啦苹果), 桃Amygdalus persica (大久保毛桃、丰白毛桃和霞光油桃), 梨Pyrus bretschneideri (砀山酥梨和玉露香梨)］果实上的钻蛀率以及在不同果实状态的4个水果品种(大久保毛桃、丰白毛桃、砀山酥梨和玉露香梨)果实上72 h的钻蛀率;比较了接卵后24 h和72 h初孵幼虫在不同发育阶段的3个苹果品种(嘎啦苹果、富士苹果和金冠苹果)果实上的钻蛀率;并测定了不同发育阶段的金冠苹果、富士苹果、嘎啦苹果、砀山酥梨和丰白毛桃上的梨小食心虫蛹重。【结果】接卵后72 h梨小食心虫初孵幼虫在6个不同水果品种果实上的钻蛀率从高到低依次为：霞光油桃＞嘎啦苹果＞砀山酥梨＞玉露香梨＞大久保毛桃＞丰白毛桃;除霞光油桃外,其他5个水果品种果实的发育阶段显著影响初孵幼虫钻蛀率。对于嘎啦苹果,接卵后72 h初孵幼虫在其幼果上的钻蛀率最高(73.69%),在其着色期果实上钻蛀率最低(32.51%);在大久保毛桃、丰白毛桃、砀山酥梨和玉露香梨上,接卵后72 h初孵幼虫的钻蛀率均随果实生长发育而增加。初孵幼虫在3 个苹果品种着色期和成熟期果实上的钻蛀率随处理时间的增加而显著下降,而在其幼果上变化不显著。寄主种类及其发育阶段也显著影响梨小食心虫蛹重,成熟毛桃和梨饲养的雌、雄蛹重显著高于未成熟果实饲养的蛹重,着色期苹果不利于蛹重的增加。【结论】果实种类及发育阶段显著影响梨小食心虫初孵幼虫钻蛀率和蛹重,取食成熟期梨和桃的梨小食心虫初孵幼虫钻蛀率和蛹重显著高于取食未成熟果实的个体。     

Effects of Trichosporon sp. in Combination with Calcium and Fungicide on Biocontrol of Postharvest Diseases in Apple Fruits

The capability of yeast Trichosporon sp., an antagonist isolated from peach fruit, in biological control was evaluated in apple ( Malus domestica Borkh. cv. Fuji) fruits, when inoculated with different concentrations of Botrytis cinerea Pers. and Penicillium expansum (Link) Thom, as well as in combination with calcium and fungicide. The concentrations of the yeast cells and pathogen spores obviously influenced disease incidence and lesion development in apples. There was a significant negative correlation between concentrations of the yeast cells and infectivity of the pathogens. When the yeast cell suspensions reached the concentration of 108 colony-forming units (CFU)/mL, there was no infection caused by B. cinerea and P. expansum with spore concentrations below 106 spores/mL in apple fruits. The yeast at concentrations of 106-107 CFU/mL in combination with fungicide (iprodione at 50 μL/L) provided control of decay caused by B. cinerea and P．expansum better than separate application. Effect of controlling gray mould and blue mould rots was enhanced when Trichosporon sp., even at low concentration of 105 CFU/mL, was applied in the presence of 1%-2% CaCl2 in an aqueous suspension.     

Occurrence and Latent Infection of Alternaria Rot of Pingguoli Pear (Pyrus bretschneideri Rehd. cv. Pingguoli) Fruits in Gansu, China

Alternaria rot of Pingguoli pear occurred after latent infection. Fruit surfaces were asymptomatic within 60 days storage under cold condition (0°C, RH 85–90%), but black‐grey hyphae could be seen in the lenticels or calyx tube of Pingguoli pear after 90 days of storage. The tissue collapsed and resulted in visible black spots as the hyphae spread over the fruit. Average incidence of Alternaria rot of fruits from an orchard in Gansu was 28.86% at 100 days of storage. The main fungus isolated from the Alternaria rot on stored Pingguoli pear was identified as Alternaria alternata (Fr. : Fr.) Keissl. This pathogen was able to initially infect the fruit via two pathways during the growing season, and then remain in a latent state. The fungus first colonized the styles at the full‐blossoming stage, and then grew into the carpel cavities progressively after 50 days from petal fall. The percentage latent infection of A. alternata was up to 45% in the carpel cavity until the harvest time. The fungus also attacked fruit surfaces and remained latent in the fruit peel during fruit development. The percentage of A. alternata latent infection at the calyx end, middle part and stem end of the fruit peel was 40%, 24% and 42.8%, respectively, at harvest time.     

Fruit Softening III. Requirement for Oxygen and pH Effects

The regulation of the softening of the cortical tissue of appleand pear fruits was investigated. Transfer of pear fruits toa nitrogen atmosphere arrested fruit softening and pectin degradationwithin 24 h. Anoxia also inhibited softening of discs cut fromripening pear fruits within 6 h, but polygalacturonase (EC 3.2.1.15 [EC] )activity was not substantially impaired and pectin degradationcontinued as in air. Discs of apple tissue softened more slowlythan pear but apple discs were firmer after 24 h under anoxiathan in air. Softening of pear tissue could be reversed by infiltration withpH 8.0 buffer or calcium chloride solution up to day 3 of ripeningat 18 °C. Buffer at pH 3.0 had no effect on fruit firmnessbut eliminated the effect of calcium in a combined treatment.A mixture of buffer at pH 80 and calcium chloride increasedfirmness more than either treatment alone. A similar reversalof softening could be achieved with apple fruit tissue afterstorage for 28 weeks.     

水杨酸（SA）对果实成熟的影响

水杨酸是一种天然抑制剂,对植物有多种多样的作用,新近研究报道,它是乙烯生物合成的一种新的抑制剂。本文用水杨酸处理番茄、苹果、梨等果实,储藏在室温下,不时检查SA对果实贮存保鲜的影响。其结果表明SA处理的果实,PG活性比对照低,而硬度大,抗病力强。番茄,苹果和梨的无病好果率比对照果提高10％以上。上述结果证明,用SA处理绿熟番茄及梨和苹果,能有效保存果实新鲜,增强抗病力和延长货架的寿命。     

Evaluation of microcapsule trunk injections for the control of apple scab and powdery mildew

A 3‐year field trial was conducted using established apple cv. Crown Gold and English oak (Quercus robur L.) to assess the efficacy of eight fungicides applied via microcapsule trunk injection against the foliar pathogens apple scab (Venturia inaequalis) and powdery mildew (Phyllactinia sp). In both apple cv. Crown Gold and English oak, the fungicide myclobutanil was not taken up when microcapsules were inserted into the tree vascular system at the root flare. Disease severity in injected trees, excluding myclobutanil, was lower over the following two growing seasons compared to water‐injected controls indicating seven of the eight fungicides used in this study provided a significant degree of protection against scab and powdery mildew infection. A difference in the magnitude of pathogen control achieved was recorded between fungicides. Of the fungicides tested, penconazole, pyrifenox and carbendazim significantly reduced disease severity and significantly increased leaf chlorophyll (Fv/Fm) and SPAD values as a measure of tree vitality and chlorophyll content, respectively, in both apple cv. Crown Gold and English oak over two growing seasons after microcapsule injection. Based on the results of this investigation, it is suggested that these three fungicides be used in preference to thiabendazole, fosetyl‐aluminium, triadimefon and propiconazole for the control of apple scab and powdery mildew where outbreaks of these foliar pathogens are problematic.     

Micronised and non-micronised sulphur applications control peach scab equally well with negligible differences in fruit quality

In a 2-year study, micronised (finely ground) and non-micronised sulphur spray programmes were investigated for peach scab control and influence on peach fruit quality variables including fruit colouration, soluble solids content and flesh firmness. Both sulphur programmes, applied six or 11 times at 15 kg ha⁻¹, controlled scab equally well in both years on cultivars (cvs) Contender and Cresthaven. Six applications of a half dosage of both micronised and non-micronised sulphur programmes were significantly less effective ( P  < 0.05) compared with all other programmes when scab incidence was >90% on cv. Contender. None of the sulphur programmes influenced significantly ( P  < 0.05) colouration and flesh firmness of harvested fruits compared with the industry standard (a chlorothalonil–captan programme). Only soluble solids concentrations showed significant differences among fungicide programmes ( P  < 0.05), but these differences were not consistent with either particle sizes of sulphur fungicide or reduced application fungicide programmes. In conclusion, our study showed that (a) micronised sulphur did not control peach scab more effectively compared to non-micronised sulphur; (b) six applications of sulphur were sufficient to control peach scab when disease pressure was low to medium; and (c) neither six nor 11 applications of sulphur-based products applied at 15 kg ha⁻¹ had commercially relevant negative impacts on important peach fruit quality variables.     

Pouteria caimito fruit derived nanoparticles inhibited the apple ring rot disease as well as extended the shelf-life of sliced apples

BackgroundApple disease, exaggerated by Botryosphaeria dothidea, is a foremost intimidating problem for extending the apple fruit shelf-life and producing substantial economic losses for cultivators and distributors. Alternate sources are urgently needed to prevent or inhibit the ring rot infection of apple fruit instigated by Botryosphaeria dothideaObjectiveIn this current study, we premeditated to make novel organic nanoparticles as of Pouteria caimito fruit extract and calcium chloride (PCNP), which were used to evaluate the preventive outcome of Botryosphaeria dothidea-caused apple disease on postharvest apple fruits.ResultsOur findings corroborated that the fruit derived nanoparticle had been confirmed for quality and size by altered estimations such as fourier transform infrared (FTIR), UV–vis spectroscopic analysis, scanning electron microscope and energy dispersive X-ray (SEM and EDX) estimation, and dynamic light scattering (DLS) analysis. In addition, we have investigated the excellent inhibitory action of the pathogen infection in apples initiated by Botryosphaeria dothidea. The protective enzymes function was pointedly improved in nanoparticle-treated apple fruits once equated with those of control apple fruits. The catalase (CAT) and superoxide dismutase (SOD) activities were pointedly improved in nanoparticle-treated fruits when compared to those of control fruits. The shelf-life extension studies were conducted for 7 days with a fresh-cut apple. The total soluble solid, pH, weight loss, and sensory studies were analyzed, and they proved the extension of sliced apple shelf life up to 7 days.ConclusionsThe discoveries of this study provided a well-organized, harmless, and environment-friendly substitute to control the apple disease as well as the durability postponement of sliced apples 7 days or may longer.     

Evaluation of the pear ester kairomone as a formulation additive for the granulovirus of codling moth (Lepidoptera: Tortricidae) in pome fruit

(E,Z) -2,4-decadienoate (pear ester) is a larval kairomone for the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). Orchard studies were conducted in 2005 and 2006 in apple, Malus domestica Borkhausen, and pear, Pyrus communis L., to evaluate a 5% active ingredient (AI), microencapsulated formulation of pear ester (PE-MEC) as an insecticidal additive for the codling moth granulovirus (CpGV). Although CpGV applied at 5-15-d intervals at commercial rates (2.2 X 10(12)-10(13) granules per ha) killed the majority (82-94%) of larvae found inside infested fruit, it did not eliminate significant damage, i.e., 30-92% fruit injury at harvest versus 51-82% in controls. PE-MEC treatments had significant but inconsistent results in our tests. In apple (mixed cultivars), PE-MEC (3.7-4.7 g [AI] /ha) plus CpGV reduced the percentage of fruit injured during the second but not the first larval generation, compared with CpGV alone, but there no was no additional population reduction (live larvae collected from infested fruit and tree bands). In 'Bartlett' pear, PE-MEC (3.7 g [AI] /ha) plus CpGV significantly increased larval mortality and reduced deep fruit entries at harvest over CpGV alone in 2006, but similar improvements were not observed in 2005 when a lower rate (1.5 g [AI] /ha) was tested. Surprisingly, compared with untreated controls, the PE-MEC formulation alone also reduced fruit injury (mid-season in Bartlett) and larval survivorship inside infested fruit at harvest (2006 apple tests and both years in Bartlett). Although pear ester seems amenable as a kairomonal adjuvant for use with insecticides, our inconsistent data with CpGV in apple and pear suggest practical improvements in formulation and application strategies (e.g., to optimize and maintain attractive release rates) are needed.     

Larval performance of the oriental fruit moth across fruits from primary and secondary hosts

A common characteristic of many invasive herbivorous insects is their ability to utilize a broad range of host plants. By using various hosts in phenological succession, multivoltine herbivores may increase the number of successful annual generations, at the same time as potentially increasing their overall fitness. To achieve such success, herbivores must be able to develop efficiently on the nutritional resources offered by their hosts. The oriental fruit moth Cydia (= Grapholita) molesta (Busck) (Lepidoptera: Tortricidae) is one of the most damaging invasive insect species. Peach (Prunus persica) is its primary host, whereas the pome fruits apple (Malus × domestica Borkh) and pear (Pyrus communis) are considered as secondary hosts. In many parts of its geographical range, including southern Europe, populations of the moth switch from peach to apple or pear orchards during the growing season. The present study tests whether this temporal switch is supported by the physiological capability of the larvae with respect to developing efficiently on fruits of these taxonomically‐related host plants. Larvae are reared on peach, apple or pear fruits; several life‐history traits are measured; and correlations between the traits are calculated. The results obtained show that larvae do not have the same physiological capability with respect to using apple or pear fruits as hosts compared with using peach fruit. Pear fruit in particular is a sub‐optimal diet. These findings suggest that, in the case of continuous geographical expansion, concomitantly with global warming, apple orchards might support oriental fruit moth populations better than pear orchards, and that the switch onto novel hosts might be accompanied by restricted population growth.     

Role of lipopeptides produced by Bacillus subtilis GA1 in the reduction of grey mould disease caused by Botrytis cinerea on apple

AIM: Test of Bacillus subtilis strain GA1 for its potential to control grey mould disease of apple caused by Botrytis cinerea. METHODS AND RESULTS: GA1 was first tested for its ability to antagonize in vitro the growth of a wide variety of plant pathogenic fungi responsible for diseases of economical importance. The potential of strain GA1 to reduce post-harvest infection caused by B. cinerea was tested on apples by treating artificially wounded fruits with endospore suspensions. Strain GA1 was very effective at reducing disease incidence during the first 5 days following pathogen inoculation and a 80% protection level was maintained over the next 10 days. Treatment of fruits with an extract of GA1 culture supernatant also exerted a strong preventive effect on the development of grey mould. Further analysis of this extract revealed that strain GA1 produces a wide variety of antifungal lipopeptide isomers from the iturin, fengycin and surfactin families. A strong evidence for the involvement of such compounds in disease reduction arose from the recovery of fengycins from protected fruit sites colonized by bacterial cells. CONCLUSIONS: The results presented here demonstrate that, despite unfavourable pH, B. subtilis endospores inoculated on apple pulp can readily germinate allowing significant cell populations to establish and efficient in vivo synthesis of lipopeptides which could be related to grey mould reduction. SIGNIFICANCE AND IMPACT OF THE STUDY: This work enables for the first time to correlate the strong protective effect of a particular B. subtilis strain against grey mould with in situ production of fengycins in infected sites of apple fruits.     

Polyribosomes from aging apple and cherry fruit

The sequence of events which occurs during the ripening of the Passe-Crassane pear fruit have been previously studied. In this work, we have investigated the ripening of another climacteric fruit (Pyrus malus L. cv Golden Delicious) and of a nonclimacteric fruit (Prunus avium L. cv Bigarreau Napoléon). We show that both climacteric fruits exhibit the same preclimacteric sequence of events. Differences exist, however, between the Golden Delicious apple and the Passe-Crassane pear in that the protein synthesis capacity of the two fruits is not the same during the over-ripening period. On the other hand, a nonclimacteric fruit, the Bigarreau Napoléon cherry, does not show an increase in its protein synthesis capacity during the over-ripening period.     

Effects of varying pollen load on fruit set,seed set and seedling performance in apple and pear

Two apple crosses and one pear cross were carried out using three different pollen densities. In one of the apple crosses, both fruit and seed set decreased when a mixture of pollen and powder (diluted pollen treatment) was used for pollination. Also, seedlings from the undiluted treatment were more vigorous than those originating from pollination with diluted pollen. In the other apple cross, however, no effect on fruit set, seed set or growth in the first year was found. Mean diameter after the second year differed among treatments, but did not seem to be related to pollen density. For pear, the number of good seeds decreased and the number of deaf, probably unfertilized, seeds increased with decreasing pollen density. However, there was no apparent significant effect of pollen density on seedling growth. With respect to scab resistance and mildew attack in both apple crosses, no differences among treatments were found. The results indicate that gametophytic competition may occur in apple crosses, but that it is probably weaker in pear.     

苹果蠹蛾滞育特性研究进展

苹果蠹蛾是苹果、梨等仁果类果树上的重要害虫,也是重要的入侵害虫。其具有寄主广泛、适生性强、蛀果为害等特点,一旦侵入很难彻底根除。老熟幼虫脱果后寻找隐蔽场所滞育的习性是其适应不利环境和维持种群繁衍的重要生存策略。本文就苹果蠹蛾幼虫滞育的诱导和终止因素、滞育场所的选取及聚集习性、滞育幼虫对环境的适应能力及内在生理生化特性以及针对滞育幼虫的防治技术等研究进行了综述,为探明苹果蠹蛾的灾变机理、预测预报和防治提供依据。     

Tufted apple bud moth (Lepidoptera: Tortricidae) management model for processing apples based on early season pheromone trap capture

Sixteen years of archived tufted apple bud moth, Platynota idaeusalis (Walker), trap capture data were compared with archived fruit injury data collected at the Penn State University Fruit Research and Extension Center to define the relationship of trap capture to fruit injury. Pheromone trap capture until 15 June was the best predictor of fruit injury at harvest. Using the regression equation of fruit injury on early season trap capture, and other assumptions about insecticide cost and fruit yield, a management model was developed for apple growers in the Mid-Atlantic region. When the model was tested on archived trap capture and fruit injury data, the results indicated that a grower would lose money on average by always treating and save money on average by never treating. By using the model, a grower could expect to save more money than by never treating. The model showed sensitivity to fruit price, insecticide price, and fruit yield.     

Response of female oriental fruit moth to volatiles from apple and peach trees at three phenological stages

The attractiveness of peach ( Prunus persica L. Batsch) and apple ( Malus domestica L. Borkh.) (both Rosaceae) tissue to gravid female oriental fruit moth, Grapholita (=  Cydia ) molesta (Busck) (Lepidoptera: Tortricidae), was assessed at three distinct stages throughout the growing season using a dual-choice bioassay. Plant material offered to the female moths consisted of a plant shoot in early spring, before fruit became available. Later, it consisted of a leaf-bearing twig and a fruit, either alone or in combination. The level of attraction of the female moths to the various plant tissues varied substantially over time and according to the plant species. Before fruit became available, female moths were significantly attracted to peach as well as to apple shoots. During the early fruit growth stage, moths were attracted to a leaf-bearing twig originating from a peach tree, but not to that from an apple tree. In peach, it was the vegetative tissue that accounted for the attraction, whereas in apple, it was the reproductive tissue (a developing fruit). During the late fruit growth stage, both peach fruit and apple fruit were highly attractive, whereas a twig with leaves from either an apple or a peach tree was neither attractive nor repellent to the female moths. This changing female olfactory response to volatiles emitted by vegetative tissue and fruits from the two host plant species with progressing season is discussed with respect to the biology and the dispersal of this moth species.