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Scab, caused by the fungal pathogen V. inaequalis (Vi), is the most economically important apple disease. During infection, Vi occupies the subcuticular environment, where it develops specialized infection structures, called stromata and runner hyphae. These structures are thought to be important for fungal nutrition and the delivery of proteins, with many of these anticipated to function as virulence factors (effectors) in promoting host infection or avirulence factors (Avr effectors) in triggering host resistance. To date, nothing is known about how these structures are differentiated and protected from recognition by the host immune system. Likewise, little is known about the identity and function of Vi effector proteins. To better control scab, a greater understanding of the molecular mechanisms underpinning infection structure differentiation and protection, as well as Vi virulence and avirulence, is first needed. In Chapter 2, a comprehensive review of apoplastic effector proteins from plant-associated fungi (and oomycetes) was provided. Given that Vi is an extracellular pathogen, this review provided insights into the potential types of effector proteins secreted by Vi into the subcuticular environment. Then, in Chapter 3, a multidisciplinary approach based on bioinformatics, transcriptomics, and structural biology was used to identify and characterize Vi effector candidates (ECs). This revealed that ECs were predominantly expressed in two temporal waves, and that many belonged to expanded protein families with predicted structural similarity to virulence and avirulence effectors from other plant-pathogenic fungi. This analysis helped to generate a list of ECs for further study and contributed to a better understanding of effector biology and evolution. Next, in Chapter 4, a multidisciplinary approach based on transcriptomics, proteomics, glycomics, and confocal microscopy was used to study Vi cell wall carbohydrate composition during the differentiation of i

Scab, caused by the biotrophic fungal pathogen Venturia inaequalis, is the most economically important disease of apples. During infection, V. inaequalis colonizes the subcuticular host environment, where it develops specialized infection structures called runner hyphae and stromata. These structures are thought to be involved in nutrient acquisition and effector (virulence factor) delivery, but also give rise to conidia that further the infection cycle. Despite their importance, very little is known about how these structures are differentiated. Likewise, nothing is known about how these structures are protected from host defenses or recognition by the host immune system. To better understand these processes, we first performed a glycosidic linkage analysis of sporulating tubular hyphae from V. inaequalis developed in culture. This analysis revealed that the V. inaequalis cell wall is mostly composed of glucans (44%) and mannans (37%), whereas chitin represents a much smaller proportion (4%). Next, we used transcriptomics and confocal laser scanning microscopy to provide insights into the cell wall carbohydrate composition of runner hyphae and stromata. These analyses revealed that, during subcuticular host colonization, genes of V. inaequalis putatively associated with the biosynthesis of immunogenic carbohydrates, such as chitin and b-1,6-glucan, are downregulated relative to growth in culture, while on the surface of runner hyphae and stromata, chitin is deacetylated to the less-immunogenic carbohydrate chitosan. These changes are anticipated to enable the subcuticular differentiation of runner hyphae and stromata by V. inaequalis, as well as to protect these structures from host defenses and recognition by the host immune system. IMPORTANCE Plant-pathogenic fungi are a major threat to food security. Among these are subcuticular pathogens, which often cause latent asymptomatic infections, making them difficult to control. A key feature of these pathogens is thei, QC 20230823

Apple scab symptoms on fruit.

Apple scab symptoms on leaves.

Apple scab symptoms on fruit.

Apple scab symptoms on leaves.

Decision support systems can be used to monitor disease development of apple scab. Decision support systems require weather data to function, which in Sweden is currently provided by conventional weather stations. Conventional weather stations supply reliable weather data if correctly installed and maintained but are costly and require continuous error-checking. Virtual weather data is becoming an increasingly popular option, where the data is calculated based on a combination of observations from local weather stations and weather radar and satellites. In this study, virtual weather data was compared with physical weather stations for apple scab monitoring, to evaluate the suitability of virtual data as a replacement for conventional weather stations. This was done by evaluating differences in predicted apple scab infections using the apple scab model in the decision support system RIMpro for the 2019 and 2020 seasons. Virtual weather data lacks the leaf wetness parameter, which had to be calculated based on other weather parameters. Thus, the use of leaf wetness calculations as an alternative to leaf wetness sensors was investigated. The study showed that virtual weather data correctly predicted the number and severity of infections, similar to conventional weather stations, with some margin of error especially for low category infections. This indicates that virtual weather data could be a suitable replacement for physical weather stations. With respect to the discrepancies seen in infection severity, few were due to a difference in leaf wetness, demonstrating that leaf wetness calculations may indeed be a suitable option for replacing leaf wetness sensors. This study was carried out after the 2020 apple scab season ended; thus, some crucial aspects were not accounted for, such as checking for errors from the weather stations during the seasons studied. Before implementation of virtual data can take place in Sweden, the virtual data should be evaluated during the

[ES] La sarna del manzano es una enfermedad comercialmente importante. Para poder controlar esta enfermedad, se utiliza una gran cantidad de fungicidas en los campos de cultivo. La opinión pública está preocupada por el uso de fungicidas y su efecto en la salud humana y el medio ambiente. Además, de otros métodos de control, los inductores de defensa de la planta pueden ser una alternativa para reducir el uso de fungicidas; particularmente Acibenzolar-S-Methyl (ingrediente activo del producto Bion). Sin embargo, no se ha realizado ningún estudio para ver los efectos de ASM en una amplia gama de cepas y si el uso repetido de ASM resulta en la selección de cepas que son menos sensibles a ASM. Para responder a esta pregunta de manejo sostenible, se realizaron experimentos en condiciones controladas sobre 94 cepas de Venturia inaequalis: 34 de huertos no tratados, 30 cepas de un huerto con Manejo Integrado de Plagas (IPM) y 30 cepas de un huerto con tratamientos de IPM y ASM ligeros. Cada cepa se inoculó en 8 plantas tratadas con ASM y 8 plantas tratadas con agua. La severidad de la enfermedad se observó en cada planta de 7 a 16 días después de la inoculación. Se encontró una amplia gama de variación de la gravedad de la enfermedad, es decir, la agresividad de las cepas. ASM fue eficaz para la mayoría de las cepas. Sin embargo, la eficiencia de ASM fue muy variable dependiendo de la cepa, y algunas cepas mostraron un efecto no significativo de ASM. La mayoría de estas cepas fueron muestreadas de huertos no tratados con ASM, solo una cepa fue muestreada del huerto tratado con ASM. Este resultado sugiere que a pesar de la existencia de cepas que tienen una baja sensibilidad a ASM, estas cepas no se seleccionaron mediante el uso repetido de ASM en un huerto manejado en IPM ligero. Se necesitan más estudios y datos para comprender este proceso., [EN] Apple scab is a commercially important disease and to control this disease a large amount of fungicides is used in orchards. People are now concern against fungicide use and its effect on human health and environment. In addition to other control methods, plant defense inducers may be a solution for reducing fungicide use; particularly Acibenzolar-S-Methyl (active ingredient of Bion product). However, no study has been done to see effects of ASM to a vast range of strains and if repeated use of ASM results in selection of strains that are less sensitive to ASM. To answer this question of sustainability experiments were conducted in controlled condition on 94 strains of Venturia inaequalis: 34 from untreated orchards, 30 strains from an orchard with light Integrated Pest Management (IPM) and 30 strains from an orchard with light IPM and ASM treatments. Each strain was inoculated on 8 ASM and 8 water- treated plants. Disease severity was observed on each plant from 7 to 16 days after inoculation. Wide range of variation of disease severity in other words aggressiveness of strains was found. ASM was effective to most of the strains. However, the efficiency of ASM was very variable depending of the strain, and a few strains showed non-significant effect of ASM. Most of them were sampled from non ASM treated orchards, only one strain was sampled from ASM treated orchard. This result suggests that despite the existence of strains that have a low sensitivity to ASM, these strains were not selected by repeated use of ASM in an orchard managed in light IPM. More study and data are needed to understand this process.

[ES] La sarna del manzano es una enfermedad comercialmente importante. Para poder controlar esta enfermedad, se utiliza una gran cantidad de fungicidas en los campos de cultivo. La opinión pública está preocupada por el uso de fungicidas y su efecto en la salud humana y el medio ambiente. Además, de otros métodos de control, los inductores de defensa de la planta pueden ser una alternativa para reducir el uso de fungicidas; particularmente Acibenzolar-S-Methyl (ingrediente activo del producto Bion). Sin embargo, no se ha realizado ningún estudio para ver los efectos de ASM en una amplia gama de cepas y si el uso repetido de ASM resulta en la selección de cepas que son menos sensibles a ASM. Para responder a esta pregunta de manejo sostenible, se realizaron experimentos en condiciones controladas sobre 94 cepas de Venturia inaequalis: 34 de huertos no tratados, 30 cepas de un huerto con Manejo Integrado de Plagas (IPM) y 30 cepas de un huerto con tratamientos de IPM y ASM ligeros. Cada cepa se inoculó en 8 plantas tratadas con ASM y 8 plantas tratadas con agua. La severidad de la enfermedad se observó en cada planta de 7 a 16 días después de la inoculación. Se encontró una amplia gama de variación de la gravedad de la enfermedad, es decir, la agresividad de las cepas. ASM fue eficaz para la mayoría de las cepas. Sin embargo, la eficiencia de ASM fue muy variable dependiendo de la cepa, y algunas cepas mostraron un efecto no significativo de ASM. La mayoría de estas cepas fueron muestreadas de huertos no tratados con ASM, solo una cepa fue muestreada del huerto tratado con ASM. Este resultado sugiere que a pesar de la existencia de cepas que tienen una baja sensibilidad a ASM, estas cepas no se seleccionaron mediante el uso repetido de ASM en un huerto manejado en IPM ligero. Se necesitan más estudios y datos para comprender este proceso., [EN] Apple scab is a commercially important disease and to control this disease a large amount of fungicides is used in orchards. People are now concern against fungicide use and its effect on human health and environment. In addition to other control methods, plant defense inducers may be a solution for reducing fungicide use; particularly Acibenzolar-S-Methyl (active ingredient of Bion product). However, no study has been done to see effects of ASM to a vast range of strains and if repeated use of ASM results in selection of strains that are less sensitive to ASM. To answer this question of sustainability experiments were conducted in controlled condition on 94 strains of Venturia inaequalis: 34 from untreated orchards, 30 strains from an orchard with light Integrated Pest Management (IPM) and 30 strains from an orchard with light IPM and ASM treatments. Each strain was inoculated on 8 ASM and 8 water- treated plants. Disease severity was observed on each plant from 7 to 16 days after inoculation. Wide range of variation of disease severity in other words aggressiveness of strains was found. ASM was effective to most of the strains. However, the efficiency of ASM was very variable depending of the strain, and a few strains showed non-significant effect of ASM. Most of them were sampled from non ASM treated orchards, only one strain was sampled from ASM treated orchard. This result suggests that despite the existence of strains that have a low sensitivity to ASM, these strains were not selected by repeated use of ASM in an orchard managed in light IPM. More study and data are needed to understand this process.

[ES] La sarna del manzano es una enfermedad comercialmente importante. Para poder controlar esta enfermedad, se utiliza una gran cantidad de fungicidas en los campos de cultivo. La opinión pública está preocupada por el uso de fungicidas y su efecto en la salud humana y el medio ambiente. Además, de otros métodos de control, los inductores de defensa de la planta pueden ser una alternativa para reducir el uso de fungicidas; particularmente Acibenzolar-S-Methyl (ingrediente activo del producto Bion). Sin embargo, no se ha realizado ningún estudio para ver los efectos de ASM en una amplia gama de cepas y si el uso repetido de ASM resulta en la selección de cepas que son menos sensibles a ASM. Para responder a esta pregunta de manejo sostenible, se realizaron experimentos en condiciones controladas sobre 94 cepas de Venturia inaequalis: 34 de huertos no tratados, 30 cepas de un huerto con Manejo Integrado de Plagas (IPM) y 30 cepas de un huerto con tratamientos de IPM y ASM ligeros. Cada cepa se inoculó en 8 plantas tratadas con ASM y 8 plantas tratadas con agua. La severidad de la enfermedad se observó en cada planta de 7 a 16 días después de la inoculación. Se encontró una amplia gama de variación de la gravedad de la enfermedad, es decir, la agresividad de las cepas. ASM fue eficaz para la mayoría de las cepas. Sin embargo, la eficiencia de ASM fue muy variable dependiendo de la cepa, y algunas cepas mostraron un efecto no significativo de ASM. La mayoría de estas cepas fueron muestreadas de huertos no tratados con ASM, solo una cepa fue muestreada del huerto tratado con ASM. Este resultado sugiere que a pesar de la existencia de cepas que tienen una baja sensibilidad a ASM, estas cepas no se seleccionaron mediante el uso repetido de ASM en un huerto manejado en IPM ligero. Se necesitan más estudios y datos para comprender este proceso., [EN] Apple scab is a commercially important disease and to control this disease a large amount of fungicides is used in orchards. People are now concern against fungicide use and its effect on human health and environment. In addition to other control methods, plant defense inducers may be a solution for reducing fungicide use; particularly Acibenzolar-S-Methyl (active ingredient of Bion product). However, no study has been done to see effects of ASM to a vast range of strains and if repeated use of ASM results in selection of strains that are less sensitive to ASM. To answer this question of sustainability experiments were conducted in controlled condition on 94 strains of Venturia inaequalis: 34 from untreated orchards, 30 strains from an orchard with light Integrated Pest Management (IPM) and 30 strains from an orchard with light IPM and ASM treatments. Each strain was inoculated on 8 ASM and 8 water- treated plants. Disease severity was observed on each plant from 7 to 16 days after inoculation. Wide range of variation of disease severity in other words aggressiveness of strains was found. ASM was effective to most of the strains. However, the efficiency of ASM was very variable depending of the strain, and a few strains showed non-significant effect of ASM. Most of them were sampled from non ASM treated orchards, only one strain was sampled from ASM treated orchard. This result suggests that despite the existence of strains that have a low sensitivity to ASM, these strains were not selected by repeated use of ASM in an orchard managed in light IPM. More study and data are needed to understand this process.

The Venturia genus comprises fungal species that are pathogens on Rosaceae host plants, including V. inaequalis and V. asperata on apple, V. aucupariae on sorbus and V. pirina on pear. Although the genetic structure of V. inaequalis populations has been investigated in detail, genomic features underlying these subdivisions remain poorly understood. Here, we report whole genome sequencing of 87 Venturia strains that represent each species and each population within V. inaequalis. We present a PacBio genome assembly for the V. inaequalis EU-B04 reference isolate. The size of selected genomes was determined by flow cytometry, and varied from 45 to 93 Mb. Genome assemblies of V. inaequalis and V. aucupariae contain a high content of transposable elements (TEs), most of which belong to the Gypsy or Copia LTR superfamilies and have been inactivated by Repeat-Induced Point mutations. The reference assembly of V. inaequalis presents a mosaic structure of GC-equilibrated regions that mainly contain predicted genes and AT-rich regions, mainly composed of TEs. Six pairs of strains were identified as clones. Single-Nucleotide Polymorphism (SNP) analysis between these clones revealed a high number of SNPs that are mostly located in AT-rich regions due to misalignments and allowed determining a false discovery rate. The availability of these genome sequences is expected to stimulate genetics and population genomics research of Venturia pathogens. Especially, it will help understanding the evolutionary history of Venturia species that are pathogenic on different hosts, a history that has probably been substantially influenced by TEs.

The Venturia genus comprises fungal species that are pathogens on Rosaceae host plants, including V. inaequalis and V. asperata on apple, V. aucupariae on sorbus and V. pirina on pear. Although the genetic structure of V. inaequalis populations has been investigated in detail, genomic features underlying these subdivisions remain poorly understood. Here, we report whole genome sequencing of 87 Venturia strains that represent each species and each population within V. inaequalis. We present a PacBio genome assembly for the V. inaequalis EU-B04 reference isolate. The size of selected genomes was determined by flow cytometry, and varied from 45 to 93 Mb. Genome assemblies of V. inaequalis and V. aucupariae contain a high content of transposable elements (TEs), most of which belong to the Gypsy or Copia LTR superfamilies and have been inactivated by Repeat-Induced Point mutations. The reference assembly of V. inaequalis presents a mosaic structure of GC-equilibrated regions that mainly contain predicted genes and AT-rich regions, mainly composed of TEs. Six pairs of strains were identified as clones. Single-Nucleotide Polymorphism (SNP) analysis between these clones revealed a high number of SNPs that are mostly located in AT-rich regions due to misalignments and allowed determining a false discovery rate. The availability of these genome sequences is expected to stimulate genetics and population genomics research of Venturia pathogens. Especially, it will help understanding the evolutionary history of Venturia species that are pathogenic on different hosts, a history that has probably been substantially influenced by TEs.

This study presents the results of a multiple-year evaluation (1991-1996; 2005-2007) of susceptibility of more than 100 apple cultivars to Venturia inaequalis, Podosphaera leucotricha and Erwinia amylovora under agroecological conditions existing in Serbia. Some of the most popular cultivars were found highly susceptible to V. inaequalis (Cripps Pink, Mutsu, Gloster 69, Wellspur); while Golden Delicious, Richared, Gala, Čačanska pozna, Čadel and Jonagold were susceptible; Idared, Granny Smith and Jonathan moderately susceptible; Lord Lamburne and London Pepping, as well as several autochthonous cultivars were moderately resistant; and a group of resistant cultivars included Prima, Priscilla, Williams Pride, Dayton, Enterprise, Gold Rush, Golden Orange, many of the Re-cultivars (Germany), as well as Baujade, Selena, Dukát, Produkta, Topaz, some older cvs. (Worcester Pearmain, Merton Worcester, James Grieve, Akane, Astilish, Astrachan Red and Discovery), some Co-op selections (USA) and NS hybrids (Serbia). Regarding powdery mildew, Idared and Jonathan were highly susceptible; Gala, Akane, Jonagold, Priscilla, Mutsu, Čačanska pozna, Golden Delicious, Granny Smith, Čadel and GoldRush were susceptible; Wellspur, Astrachan Red, Richared, Jonadel, Dayton and several autochthonous cultivars were moderately susceptible; Lord Lamburne, Astlisch, Prima, Champagne Reinette, Discovery and many autochthonous cultivars were moderately resistant; while most Re-cvs. (Germany), several cultivars from the Czech Republic, some selections from the USA and UK and most NS hybrids (Serbia) were resistant. Also, some cultivars showed variable susceptibility depending on location (Williams Pride, Gloster 69, Baujade and Produkta). E. amylovora was observed only in 2007 and at relatively low intensity (up to 12% infection). The highest disease severity was observed on cv. Elstar, then Granny Smith, Idared and Jonagored; while the lowest was found on Red Chief and Hapke apple trees., Ovaj rad prikazuje rezultate višegodišnjeg proučavanja (1991-1996; 2005-2007) osetljivosti više od 100 sorti jabuke prema patogenima Venturia inaequalis, Podosphaera leucotricha i Erwinia amylovora u agroekološkim uslovima Srbije. Neke od dobro poznatih sorti su visoko osetljive prema V. inaequalis (Cripps Pink, Mutsu, Gloster 69, Wellspur); osetljive su Golden Delicious, Richared, Gala, Čačanska pozna, Čadel i Jonagold; umereno osetljive su Idared, Granny Smith i Jonathan; umereno otporne su Lord Lamburne i London Pepping, kao i nekoliko autohtonih sorti; grupa otpornih uključuje sorte Prima, Priscilla, Williams Pride, Dayton, Enterprise, Gold Rush, Golden Orange, mnoge Re-sorte (Nemačka), Baujade, Selena, Dukát, Produkta, Topaz, neke starije sorte (Worcester Pearmain, Merton Worcester, James Grieve, Akane, Astilish, Astrachan Red i Discovery), neke Co-op selekcije (USA) i NS hibridi (Srbija). Prema pepelnici vrlo osetljive su bile sorte Idared i Jonathan; osetljive Gala, Akane, Jonagold, Priscilla, Mutsu, Čačanska pozna, Golden Delicious, Granny Smith, Čadel i GoldRush; umereno osetljive Wellspur, Astrachan Red, Richared, Jonadel, Dayton i nekoliko autohtonih sorti; umereno otporne su Lord Lamburne, Astlisch, Prima, Champagne Reinette, Discovery i mnoge autohtone sorte; i otporne su Re-sorte, nekoliko sorti iz Češke Republike, neke selekcije poreklom iz USA i UK i većina NS hibrida. Takođe, neke sorte su i varirale u osetljivosti (Williams Pride, Gloster 69, Baujade i Produkta). E. amylovora je beležena samo 2007. godine sa relativno malim intenzitetom bolesti (infekcija do 12%). Najveći intenzitet bolesti je primećen kod sorte Elstar, zatim slede sorte Granny Smith, Idared, Jonagored; a najmanji intenzitet je bio kod sorti Red Chief i Hapke.

Reducing apple (Malus x domestica Borkh.) crop load during bloom is a reliable option for increasing fruit quality and return bloom. In this thesis, multiple approaches to improving bloom thinning practices are discussed. The first project analyzed the pollen tube growth of several crabapple cultivars. Previous research had improved the use of bloom thinning chemicals, by coordinating the application timing with the pollen tube growth between pollination and fertilization. However, pollen tube growth rates have only been measured in a few genotypes. In Chapter 2, the pollen tube growth rates of five crabapple cultivars were measured in the styles of 'Fuji', 'Golden Delicious', and 'Pink Lady' flowers, at four temperatures 12, 18, 24 and 30 C. Complex relationships were found among paternal pollen tube growth, maternal cultivar, and temperature. Chapters 3 and 4 describe projects where organically-approved chemicals, including the biofungicide, Regalia, were evaluated for their ability to simultaneously reduce crop load and decrease early season disease infection. These chemicals were applied in conventionally managed orchards (Chapter 3), and in an organically-managed 'Honeycrisp' orchard (Chapter 4). The number of chemicals approved for bloom thinning is limited, especially in the Eastern U.S. where lime sulfur and oil applications are not permitted during bloom. These studies indicate Regalia, applied during bloom, can reduce crop load and provide early season disease control. The research presented in this thesis provides new knowledge that can be incorporated into crop load management practices in both conventional and organic apple orchards.

Pesticides represent the major input in pome fruit across Europe. They are mainly used on a calendar-based approach in order to control a large number of pests and diseases causing both direct and indirect losses. This situation has stimulated research for innovative tools and methods for pest management and the PURE project (. www.pure-ipm.eu) organised a biointensive framework to demonstrate that several solutions are now available but they need to be properly transferred to the growers to be applied on a large scale. This paper presents the experience of the PURE project across demonstration orchards in different countries. The aim was to develop a multicriteria evaluation to help more clearly define the advantages and disadvantages of applying innovative Integrated Pest Management (IPM) systems, for different pests (pear psylla and apple codling moth) and diseases (pear brown spot and apple scab) on pome fruit, compared to standard IPM (i.e. currently adopted IPM system). The multicriteria approach permitted to assess environmental risks, economic effects and sustainability impact for each of the innovative systems tested. This multicriteria assessment showed that, in general, innovative performed better than standard for environmental quality and provided similar yield and pest management without any significant extra costs.

The study on resource management for apple scab and sanjose scale of apple in Kashmir Valley of J&K State was conducted purposively in Sopore and Patten tehsils of Baramulla district covering 4 villages with a sample size of 200 apple growers selected through random sampling method. The study revealed that all the apple growers (100%) from rainfed and irrigated areas were applying the resource management practices such as checking the expiry of chemical before purchase, undertake precautions while using chemicals and sprayers, purchaseeconomical and convenient packing’s of plant protection chemicals, check the working condition of the sprayers on regular basis, undertaking care and maintenance of sprayers regularly and were able to repair the minor defects of sprayers by self followed by (66%) apple growers who had decided to planed plant protection schedule in advance. The data further showed that hired labour for disease and pest management of apple were available easily and locally, and as per requirement (100%). As regards prevailing wage rates (88%) farmers from rainfed and (91%) from irrigated area reported that these were reasonable. Plant protection chemicals needed for control of disease and pest of apple were found adopted by cent per cent farmers. The plant protection chemicals were also available in suitable packings (97%) and before the expiry date (96%). The critical evaluation of the plant protection chemicals and equipments before their use with regard to their quality being taken care by all the apple growers would help in eradication of the disease from the region.

Venturia inaequalis is a common apple disease in Serbia and its intensity depends on weather conditions. The most successful method of combating apple scab is to use a lower dose of an active ingredient and increase its effectiveness by adding substances that do not cause environmental damage. The effectiveness of a fungicide mixture of captan and potassium phosphite against V. inaequalis was investigated in apple orchards in 2008 and 2009. A relevant EPPO standard method was used in all trials. Captan 50 WP was used as a standard fungicide. In order to determine the exact conditions marking the onset of apple infection, key meteorological conditions were monitored in the orchards using an automated iMetos weather station and a Lufft electronic instrument. The results showed high efficacy of the tested fungicides which remained similar in both years of investigation. The intensity of leaf infection after treatment with the mixture of captan and potassium phosphite was 0.7-2.4%, while fruit infection was 0.5-3.0%. The efficacy of this mixture ranged from 96.3-97.9% on leaves and 87.4-98.7% on fruits. The standard fungicide Captan 50 WP showed an efficacy ranging from 95.3-96.7% on leaves and from 87.8-99.3% on fruits. No statistically significant differences were found between the fungicide tested and the standard fungicide., Venturia inaequalis je široko rasprostranjena bolest jabuke u Srbiji, a njen intenzitet zavisi od vremenskih uslova. Najuspešniji metod borbe protiv čađave krastavosti jabuke je korišćenje manjih doza aktivnih materija uz istovremeno povećavanje efikasnosti dodavanjem supstanci koje ne prouzrokuju štetu u životnoj sredini. Tokom 2008 i 2009 godine, proučavana je efikasnost fungicidne mešavine kaptana i kalijum fosfita protiv V. inaequalis u jabučnjacima. U svim ogledima je korišćen standardni EPPO metod. Captan 50 WP je korišćen kao standardni fungicid. Kako bi se tačno odredili uslovi za početak zaraze na jabuci, praćeni su osnovni meteorološki parametri u voćnjacima pomoću iMetos stanice i elektronskog uređaja Lufft. Rezultati su pokazali visoku efikasnost testiranih fungicida koja je bila slična u obe godine istraživanja. Intenzitet zaraze lista nakon tretmana mešavinom kaptana i kalijum fosfita bio je 0.7-2.4%, dok je zaraženost plodova bila 0.5-3.0%. Efikasnost mešavine bila je 96.3-97.9% na listovima, a 87.4-98.7% na plodovima. Standardni fungicid Captan 50 WP pokazao je efikasnost u opsegu 95.3-96.7% na listovima i 87.8-99.3% na plodovima. Nisu konstatovane statistički značajne razlike između ispitivanog i standardnog fungicida.

Copper citrate is a complex compound of copper, which is characterized by a higher degree of dissociation in relation to the other copper compounds that are presently in the use and can be used in lower concentrations for the control of plant pathogens. Apple scab (Venturia inaequalis) is on of the economically most important diseases of apples in all regions where this fruit species grown. A successful apple production is not possible without intensive chemical control. The use of copperbased products to protect apples, positioned at the start of the growing season. The earliest apple infections are the most destructive, and the effective protection of the apples in this period is very important. The aim of this study was to evaluate in vitro the influence of copper citrate at different concentrations applied to the growth of V. inaequalis colonies. The results show that copper citrate in significantly lower concentrations of application 0.2 and 0.1 % higher than the standard product, effectively inhibiting the growth of V. inaequali mycelium (colony), which is the result of significantly higher amounts of copper ions, that is released from compound., Bakar-citrat je kompleksno jedinjenje bakra koje se odlikuje višim stepenom disocijacije u odnosu na druga bakarna jedinjenja koja su trenutno u primeni pa se može koristiti u nižim koncentracijama za suzbijanje biljnih patogena. Čađava pegavost lista i krastavost plodova (Venturia inaequalis) je jedna od ekonomski najštetnijih bolesti jabuke u svim regionima gde se ova voćna vrsta gaji. Uspešna proizvodnja jabuke nije moguća bez izvođenja intenzivnih hemijskih mera zaštite. Primena preparata na bazi bakra u zaštiti jabuke, pozicionirana je na sam početak vegetacije. Najranije zaraze jabuke su i najdestruktivnije, pa je efikasna zaštita jabuke u ovom periodu veoma važna. Cilj ovog rada je da se u in vitro uslovima ispita uticaj bakar-citrata u različitim koncentracijama primene na porast kolonija Venturia inaequalis. Dobijeni rezultati pokazuju da bakar citrat u znatno nižim koncentracijama primene 0,2 i 0,1% nego sandardni preparat, efikasno blokira porast micelije (kolonija) fitopatogene gljive V. inaequalis, što je rezultat znatno veće količine bakarnih jona koje ovo jedinjenje oslobađa.

Apple scab caused by Venturia inaequalis (Cooke) G. Winter is recognized as the most important disease of apples in Serbia. Fungicides remain the primary tool for managing this disease and, due to its polycyclic nature; repeated applications are required over the course of a single season. During 2004-2010 we have conducted many trials for evaluation of chemical control of this disease. The following compounds were tested: pyraclostrobin + dithianon, trifloxystrobin + captan, kresoxim-methyl + dithianon, difenoconazole, pirimethanil, boscalid + pyraclostrobin, pyrimethanil + fluquinconazol and fenbuconazole. Trials were set according to EPPO guideline PP 1/5(3). A complete randomized block design with four replicates per treatment was used in the experiments. Mean percent disease control values were calculated from the evaluations made towards the end of the trials, when differentiation between the treatments was the most obvious. Data were analysed by one-way completely randomized ANOVA, and means comparison performed by Duncan's test. The infection of untreated control plots ranged from 23.0% to 77.5%. All treatments were effective against V. ineaqualis and significantly reduced disease severity in all experiments, compared with the untreated control. Comparing the tested fungicides, pyrimethanil applied alone and mixtures of trifloxystrobin + captan, kresoxim-methyl + dithianon, pyrimethanil + fluquinconazol and pyraclostrobin + dithianon demonstrated the highest efficacy in all trials (85.6%-97.2%). DMI fungicides (difenoconazole and fenbuconazole) and mixture of boscalid + pyraclostrobin exhibited lower efficacy (68.5%-75.1%) compared to other tested materials.

Apple scab (causal organism: Venturia inaequalis) is an economically devastating disease of apples that is predominantly controlled with fungicides. Of the chemical classes currently available, the sterol-inhibiting (SI) and strobilurin (QoI) fungicides are the most commonly used. Recent observations indicate that V. inaequalis populations in Virginia have developed resistance to myclobutanil and other SIs. However, little is known about the frequency and distribution of SI and QoI resistance in Virginia's scab populations. The first objective of this research was to evaluate V. inaequalis populations in Virginia for SI and QoI resistance. Fungal isolates were collected from experimental orchards at the Alson H. Smith Jr., Agricultural Research and Extension Center (AHS AREC) and from commercial orchards in Virginia and Maryland. Sensitivities were determined by assessing colony growth at 19°C on potato dextrose agar (PDA) amended with 0 or 1.0 µg ml-1 of myclobutanil (SI) (N=87) or trifloxystrobin (QoI) (N=25) at 28 days. A range of fungicide sensitivity was observed for both chemical classes. The second objective of this research was to monitor the temporal dynamics of SI resistance over five sequential field seasons. To monitor shoot growth, neon rubber bands were placed over actively growing shoot tips following myclobutanil application or sample collection. Fungal isolates were collected from the same trees from 2007 through 2010 (N=176) and compared with isolates collected from wild apple seedlings (N=3). A continuum of SI resistance was observed for each year, and the V. inaequalis population exhibited a baseline shifted toward reduced sensitivity. The third objective of this research was to examine the spatial distribution of SI fungicide resistance within the tree canopy in a lower-density orchard (less than 150 trees A-1). Leaves collected from larger trees (>8m) in a lower-density orchard at the AHS AREC were analyzed for manganese deposition, pre- and po

Apple scab caused by Venturia inaequalis (Cooke) G. Winter is recognized as the most important disease of apples in Serbia. Fungicides remain the primary tool for managing this disease and, due to its polycyclic nature; repeated applications are required over the course of a single season. During 2004-2010 we have conducted many trials for evaluation of chemical control of this disease. The following compounds were tested: pyraclostrobin + dithianon, trifloxystrobin + captan, kresoximmethyl + dithianon, difenoconazole, pirimethanil, boscalid + pyraclostrobin, pyrimethanil + fluquinconazol and fenbuconazole. Trials were set according to EPPO guideline PP 1/5(3). A complete randomized block design with four replicates per treatment was used in the experiments. Mean percent disease control values were calculated from the evaluations made towards the end of the trials, when differentiation between the treatments was the most obvious. Data were analysed by one-way completely randomized ANOVA, and means comparison performed by Duncan's test. The infection of untreated control plots ranged from 23.0% to 77.5%. All treatments were effective against V. ineaqualis and significantly reduced disease severity in all experiments, compared with the untreated control. Comparing the tested fungicides, pyrimethanil applied alone and mixtures of trifloxystrobin + captan, kresoxim-methyl + dithianon, pyrimethanil + fluquinconazol and pyraclostrobin + dithianon demonstrated the highest efficacy in all trials (85.6%-97.2%). DMI fungicides (difenoconazole and fenbuconazole) and mixture of boscalid + pyraclostrobin exhibited lower efficacy (68.5% - 75.1%) compared to other tested materials.

Ispitivana je efikasnost nekoliko kombinacija fungicida u suzbijanju Venturia inaequalis na jabuci u poljskim uslovima. U 2005-oj i 2006-oj godini ispitivana je efikasnost Flint Plus (trifloksistrobin + kaptan) i Tercel (piraklostrobin + ditianon) u odnosu na standardne fungicide Zato 50-WG (trifloksistrobin) i Stroby + Delan (kresoksim-methil + ditianon) na lokalitetima Mihajlovac, Radmilovac i Landol. Oba ispitivana fungicida ispoljila su visoku efikasnost u suzbijanju čađave pagavosti jabuke. Između efikasnosti Flint Plus (91.3-98.5%) i Zato 50-WG (68.2% i 78.4%), i Tercel (88.7-93.5%) i kombinacije fungicida Stroby + Delan (77.9% i 82.1%) zabeležena je statistički značajna razlika. Naši ogledi su pokazali da su ispitivane kombinacije fungicida visoko efikasne protiv V. inaequalis čak i u uslovima jake zaraze., The efficacy of several fungicide mixtures in controlling Venturia inaequalis in apple was evaluated in field trials. The efficacies of Flint Plus (trifloxystrobin + captan) and Tercel (pyraclostrobin + dithianon) in comparison with standard fungicides Zato 50-WG (trifloxystrobin) and Stroby + Delan (kresoxim-methyl + dithianon) were tested in the localities Mihajlovac, Radmilovac and Landol in 2004 and 2005. Both tested fungicides exhibited high efficacy in controlling apple scab. There were significant differences in the efficacies of Flint Plus (91.3-98.5%) and Zato 50-WG (68.2% and 78.4%); and Tercel (88.7-93.5%) and Stroby + Delan (77.9% and 82.1%). Our experiments showed that the investigated fungicide mixtures are highly effective against V. inaqeulais, even under high disease pressure.

Black spot or apple scab is a major disease in apple (Malus domestica) production. Its control is especially difficult in organic production systems that rely on copper- and sulphur-based fungicides which are not very effective and demand a high number of applications throughout the season. The most commonly used fungicide in organic apple production is lime sulphur, which is known to be phytotoxic, especially towards the cultivar 'Braeburn'. The influence of different application rates of lime sulphur (1% anti 2%) was evaluated when applied 11 times throughout the growing season from October to February. As varieties differ in their susceptibility to lime sulphur, the two cultivars 'Royal Gala' and 'Braeburn' were compared in this study. Black spot incidence and severity, russet development and postharvest quality parameters were evaluated. At harvest, residues of sulphur on and in the apple were determined as total sulphur, total water-soluble non-protein thiol compounds and cysteine content. Both cultivars behaved similarly to the application of lime sulphur, but 'Braeburn' was affected to a greater extent. Lime sulphur decreased background colour, blush, firmness, soluble solids content and dry matter content in both cultivars; fruit size in 'Braeburn' and titratable acidity in 'Royal Gala'. The changes observed can possibly be attributed at least in part to the decrease in the photosynthetic rate, which was especially drastic in 'Braeburn'. Lime sulphur caused increased russet on 'Royal Gala', but not on 'Braeburn'. Significant sulphur residues were found in the skin and flesh of both cultivars and part of the lime sulphur applied was metabolized into water-soluble non-protein thiols and cysteine. These results are of significant interest to the organic industry as the use of lime sulphur may compromise the residue-free status of organic apples and could have an influence on consumer acceptance and flavour.

The efficacy of several fungicide mixtures in controlling Venturia inaequalis in apple was evaluated in field trials. The efficacies of Flint Plus (trifloxystrobin + captan) and Tercel (pyraclostrobin + dithianon) in comparison with standard fungicides Zato 50-WG (trifloxystrobin) and Stroby + Delan (kresoxim-methyl + dithianon) were tested in the localities Mihajlovac, Radmilovac and Landol in 2004 and 2005. Both tested fungicides exhibited high efficacy in controlling apple scab. There were significant differences in the efficacies of Flint Plus (91.3-98.5%) and Zato 50-WG (68.2% and 78.4%); and Tercel (88.7-93.5%) and Stroby + Delan (77.9% and 82.1%). Our experiments showed that the investigated fungicide mixtures are highly effective against V. inaqeulais, even under high disease pressure., Ispitivana je efikasnost nekoliko kombinacija fungicida u suzbijanju Venturia inaequalis na jabuci u poljskim uslovima. U 2005-oj i 2006-oj godini ispitivana je efikasnost Flint Plus (trifloksistrobin + kaptan) i Tercel (piraklostrobin + ditianon) u odnosu na standardne fungicide Zato 50-WG (trifloksistrobin) i Stroby + Delan (kresoksim-methil + ditianon) na lokalitetima Mihajlovac, Radmilovac i Landol. Oba ispitivana fungicida ispoljila su visoku efikasnost u suzbijanju čađave pagavosti jabuke. Između efikasnosti Flint Plus (91.3-98.5%) i Zato 50-WG (68.2% i 78.4%), i Tercel (88.7-93.5%) i kombinacije fungicida Stroby + Delan (77.9% i 82.1%) zabeležena je statistički značajna razlika. Naši ogledi su pokazali da su ispitivane kombinacije fungicida visoko efikasne protiv V. inaequalis čak i u uslovima jake zaraze.

Distribution of Venturia inaequalis ascospores versus time during an infection event was investigated by integrating in a dynamic simulation model the available knowledge on the biology of infection processes and the effect of environmental conditions. Processes of spore immigration on leaf surface, germination, appressorium formation, and successful infection establishment were incorporated into the model by elaborating mathematical equations depending on air temperature and length of the wet period. Survival of spores belonging to different development stages (ungerminated, germinated, with appressorium) was also included in the model as a function of temperature, relative humidity, and duration of wetness interruption. Based on comparison with previously published data the architecture of the model and its algorithms can be considered accurate and robust. Nevertheless, validation of model simulations under orchard conditions will be necessary before its use in management decisions.

The largest number of fungicide treatments in disease control of apple are realised against apple scab. However, a small number of available fungicides which were frequently used in increased doses caused the problems of less susceptibility of pathogen to applied fungicides. The effect of different temperatures and media on pathogen colony growth and sporulation were investigated to find out the optimal conditions for pathogen development. The optimal temperature for colony growth was 15-20ºC, minimal around 1ºC, a maximal 27ºC. The most suitable medium for pathogen sporulatuiin was malt agar, and insignificantly less suitable was PDA. Sporulation was the more abundant at 15ºC (1,6 x 105 spora/ml)., Najveći broj tretmana u zaštiti jabuke izvodi se protiv prouzrokovača čađave pegavosti lista i krastavost plodova. Međutim, mali broj raspoloživih fungicida, često primenjih u povećanim količinama, uzrokuje pojavu smanjene osetljivosti patogena prema upotrebljavanim fungicidima. Zato se javila potreba ispitivanja ove pojave i u laboratorijskim uslovima. Da bi se ova istraživanja sprovela potrebno je ispitati uslove pod kojima patogen ima optimalni porast i fruktifikaciju, u cilju iznalaženja najboljih podloga i uslova za gajenje patogena koji bi poslužili u ispitivanjima njegove osetljivosti prema fungcidima u laboratorijskim uslovima. Prema dobijenim rezultatima, temperaturni optimum za porast kolonija je između 15º i 20ºC, minimum je oko 1ºC, a maksimum je 27ºC. Najpogodnija podloga za sporulaciju patogena je podloga od slada, a neznatno slabija sporulacija je na podlozi od krompira. Utvrđeno je da je intenzitet sporulacije najveći pri temperaturi od 15ºC, na podlozi od slada (1, 6 x 105 spora/ml).

The largest number of fungicide treatments in disease control of apple are realised against apple scab. However, a small number of available fungicides which were frequently used in increased doses caused the problems of less susceptibility of pathogen to applied fungicides. The effect of different temperatures and media on pathogen colony growth and sporulation were investigated to find out the optimal conditions for pathogen development. The optimal temperature for colony growth was 15-20ºC, minimal around 1ºC, a maximal 27ºC. The most suitable medium for pathogen sporulatuiin was malt agar, and insignificantly less suitable was PDA. Sporulation was the more abundant at 15ºC (1,6 x 105 spora/ml)., Najveći broj tretmana u zaštiti jabuke izvodi se protiv prouzrokovača čađave pegavosti lista i krastavost plodova. Međutim, mali broj raspoloživih fungicida, često primenjih u povećanim količinama, uzrokuje pojavu smanjene osetljivosti patogena prema upotrebljavanim fungicidima. Zato se javila potreba ispitivanja ove pojave i u laboratorijskim uslovima. Da bi se ova istraživanja sprovela potrebno je ispitati uslove pod kojima patogen ima optimalni porast i fruktifikaciju, u cilju iznalaženja najboljih podloga i uslova za gajenje patogena koji bi poslužili u ispitivanjima njegove osetljivosti prema fungcidima u laboratorijskim uslovima. Prema dobijenim rezultatima, temperaturni optimum za porast kolonija je između 15º i 20ºC, minimum je oko 1ºC, a maksimum je 27ºC. Najpogodnija podloga za sporulaciju patogena je podloga od slada, a neznatno slabija sporulacija je na podlozi od krompira. Utvrđeno je da je intenzitet sporulacije najveći pri temperaturi od 15ºC, na podlozi od slada (1, 6 x 105 spora/ml).

Coniothyrium-like coelomycetes are drawing attention as biological control agents, potential bioremediators, and producers of antibiotics. Four genera are currently used to classify such anamorphs, namely, Coniothyrium, Microsphaeropsis, Cyclothyrium, and Cytoplea. The morphological plasticity of these fungi, however, makes it difficult to ascertain their best generic disposition in many cases. A new genus, Paraconiothyrium is here proposed to accommodate four new species, P. estuarinum, P. brasiliense, P. cyclothyrioides, and P. fungicola. Their formal descriptions are based on anamorphic characters as seen in vitro. The teleomorphs of these species are unknown, but maximum parsimony analysis of ITS and partial SSU nrDNA sequences showed that they belong in the Pleosporales and group in a clade including Paraphaeosphaeria s. str., the biocontrol agent Coniothyrium minitans, and the ubiquitous soil fungus Coniothyrium sporulosum. Coniothyrium minitans and C. sporulosum are therefore also combined into the genus Paraconiothyrium. The anamorphs of Paraphaeosphaeria michotii and Paraphaeosphaeria pilleata are regarded representative of Paraconiothyrium, but remain formally unnamed. Paraconiothyrium species are phylogenetically distant from typical members of the other coelomycete genera mentioned above

The influence of air temperature on the release pattern of Venturia inaequalis ascospores was studied by volumetric spore samplers in two spore sampling periods. In the first period (1991-1996; Passo Segni, Ferrara), 15 ascospore dispersal events were considered occurring in daylight, with high spore counts (168-5892 ascospores per m3 air per event), at an average temperature between 8.4 and 20.3°C. Both the length of the ascospore release period and distribution of airborne spores over time were significantly influenced by temperature. A logistic regression model was used to fit the proportion of ascospores trapped from the orchard air as a function of time after the beginning of the discharge event and air temperature. The accuracy of this equation was tested against data collected in the second spore sampling period (1997-2000; Sala Bolognese, Bologna, and Castelfranco, Modena); 16 dispersal events were considered, triggered by rainfall that occurred both in the dark and in daylight, with low to high spore counts (29-458 ascospores per m3 air per event), at an average temperature between 2.8 and 14.3°C. There was a general agreement between the proportion of ascospores trapped from the orchard air during these events and that estimated by using the logistic equation - in most cases, actual and estimated values showed a high coincidence. Statistical comparison showed a significant correlation (r = 0.93, P < 0.01) between observed and estimated data.

Apple foliar and fruit scab is mostly spread and, concerning the harmful consequences, economically most important apple disease in our country. The causal agent is a phytopathogenous fungus having two developmental phases: saprophytic - teleomorphic (Venturia inaequalis (Cooke) Winter) and parasitic - anamorphic (Spilocaea pomi Fr.). It is the disease that occurs every year, but not at the same time and with the same severity. Cause is the effect of the different factors, among which the most significant are: pseudothecia maturing period and ascospore discharge (beginning and ending), severity and dynamics of ascospore discharge, the beginning of folliation and rate that apple leaf mass increases, distribution of rainfalls and dew, length of wetting period and air temperature. Based on the knowledge of biological and epidemiological characteristics of pathogen and monitoring the meteorological indicators, the conditions required for occurrence and spread of the disease can be registered and consequently the deadlines and modes of applications of control measure can be determined. The basic concept in forecasting and controlling infection should be based on making efforts to prevent primary infections in the course of a whole ascospore discharge period, specially pointing to blocking the earliest infections. If these efforts were made successfully, all problems that would be caused by occurrence and spread of secondary infections would be dealt with. From experience and according to the results obtained for many years of the Institute for plant protection and environment from Belgrade, with an aim to successful forecasting occurrence and spread as well as efficient control of this disease, it is necessary to observe the following procedures: Monitoring the saprophytic phase of the causal agent of a disease - Monitoring apple phenology - Monitoring meteorological conditions needed for realization of infections - Determination of method of apple orchard protection (ch

Utah pests fact sheet about the description and management of apple scab, caused by the fungus Venturia inaequalis, that has occurred infrequently throughout Utah apple orchards.

Utah pests fact sheet about the description and management of apple scab, caused by the fungus Venturia inaequalis, that has occurred infrequently throughout Utah apple orchards.

Cílem této diplomové práce bylo stanovit aromaticky aktivní látky a sledovat senzorickou kvalitu jablek. Teoretická část se zabývá popisem, složením a vlastnostmi jablek, také informuje o aromatických látkách, jejich stanovení a možnostech senzorického hodnocení jablek. Je zde popsána metoda stanovení aromaticky aktivních látek pomocí plynové chromatografie v kombinaci s izolační technikou mikroextrakce tuhou fází. V experimentální části byla metoda SPME-GC-FID aplikována na vzorky jablek vybraných odrůd speciálně šlechtěných proti strupovitosti (Venturia inaequalis), což bylo 24 genotypů a odrůda Golden Delicious jako standard. Celkem bylo identifikováno 60 různých aromaticky aktivních látek, z toho 22 alkoholů, 12 aldehydů, 11 ketonů, 10 esterů a 5 organických kyselin. Počet a koncentrace identifikovaných látek se lišily v závislosti na odrůdě. Senzorická analýza byla provedena pomocí kategorových ordinálních stupnic a profilového testu., The aim of this master‘s thesis was to determine the aroma active compounds and monitor the sensory quality of apples. The theoretical part deals with the description, composition and properties of apples, information about the aroma compounds, their determination and possibilities for sensory evaluation of apples is also given. The gas chromatography method combined with the solid-phase microextraction, utilized for the specification of aroma compounds, is described. In the experimental part, the SPME-GC-FID method was applied on selected cultivars of apples specially cultivated against apple scab (Venturia inaequalis), i.e. 24 genotypes and Golden Delicious as the control variety. In total 60 various aroma compounds were identified, 22 alcohols, 12 aldehydes, 11 ketones, 10 esters and 5 organic acids. The number and concentration of compounds identified differed according to the cultivars. Sensory analysis was performed using category ordinal scales and the profile test.

Cílem této diplomové práce bylo stanovit aromaticky aktivní látky a sledovat senzorickou kvalitu jablek. Teoretická část se zabývá popisem, složením a vlastnostmi jablek, také informuje o aromatických látkách, jejich stanovení a možnostech senzorického hodnocení jablek. Je zde popsána metoda stanovení aromaticky aktivních látek pomocí plynové chromatografie v kombinaci s izolační technikou mikroextrakce tuhou fází. V experimentální části byla metoda SPME-GC-FID aplikována na vzorky jablek vybraných odrůd speciálně šlechtěných proti strupovitosti (Venturia inaequalis), což bylo 24 genotypů a odrůda Golden Delicious jako standard. Celkem bylo identifikováno 60 různých aromaticky aktivních látek, z toho 22 alkoholů, 12 aldehydů, 11 ketonů, 10 esterů a 5 organických kyselin. Počet a koncentrace identifikovaných látek se lišily v závislosti na odrůdě. Senzorická analýza byla provedena pomocí kategorových ordinálních stupnic a profilového testu., The aim of this master‘s thesis was to determine the aroma active compounds and monitor the sensory quality of apples. The theoretical part deals with the description, composition and properties of apples, information about the aroma compounds, their determination and possibilities for sensory evaluation of apples is also given. The gas chromatography method combined with the solid-phase microextraction, utilized for the specification of aroma compounds, is described. In the experimental part, the SPME-GC-FID method was applied on selected cultivars of apples specially cultivated against apple scab (Venturia inaequalis), i.e. 24 genotypes and Golden Delicious as the control variety. In total 60 various aroma compounds were identified, 22 alcohols, 12 aldehydes, 11 ketones, 10 esters and 5 organic acids. The number and concentration of compounds identified differed according to the cultivars. Sensory analysis was performed using category ordinal scales and the profile test.

Cílem této diplomové práce bylo stanovit aromaticky aktivní látky a sledovat senzorickou kvalitu jablek. Teoretická část se zabývá popisem, složením a vlastnostmi jablek, také informuje o aromatických látkách, jejich stanovení a možnostech senzorického hodnocení jablek. Je zde popsána metoda stanovení aromaticky aktivních látek pomocí plynové chromatografie v kombinaci s izolační technikou mikroextrakce tuhou fází. V experimentální části byla metoda SPME-GC-FID aplikována na vzorky jablek vybraných odrůd speciálně šlechtěných proti strupovitosti (Venturia inaequalis), což bylo 24 genotypů a odrůda Golden Delicious jako standard. Celkem bylo identifikováno 60 různých aromaticky aktivních látek, z toho 22 alkoholů, 12 aldehydů, 11 ketonů, 10 esterů a 5 organických kyselin. Počet a koncentrace identifikovaných látek se lišily v závislosti na odrůdě. Senzorická analýza byla provedena pomocí kategorových ordinálních stupnic a profilového testu., The aim of this master‘s thesis was to determine the aroma active compounds and monitor the sensory quality of apples. The theoretical part deals with the description, composition and properties of apples, information about the aroma compounds, their determination and possibilities for sensory evaluation of apples is also given. The gas chromatography method combined with the solid-phase microextraction, utilized for the specification of aroma compounds, is described. In the experimental part, the SPME-GC-FID method was applied on selected cultivars of apples specially cultivated against apple scab (Venturia inaequalis), i.e. 24 genotypes and Golden Delicious as the control variety. In total 60 various aroma compounds were identified, 22 alcohols, 12 aldehydes, 11 ketones, 10 esters and 5 organic acids. The number and concentration of compounds identified differed according to the cultivars. Sensory analysis was performed using category ordinal scales and the profile test.

Cílem této diplomové práce bylo stanovit aromaticky aktivní látky a sledovat senzorickou kvalitu jablek. Teoretická část se zabývá popisem, složením a vlastnostmi jablek, také informuje o aromatických látkách, jejich stanovení a možnostech senzorického hodnocení jablek. Je zde popsána metoda stanovení aromaticky aktivních látek pomocí plynové chromatografie v kombinaci s izolační technikou mikroextrakce tuhou fází. V experimentální části byla metoda SPME-GC-FID aplikována na vzorky jablek vybraných odrůd speciálně šlechtěných proti strupovitosti (Venturia inaequalis), což bylo 24 genotypů a odrůda Golden Delicious jako standard. Celkem bylo identifikováno 60 různých aromaticky aktivních látek, z toho 22 alkoholů, 12 aldehydů, 11 ketonů, 10 esterů a 5 organických kyselin. Počet a koncentrace identifikovaných látek se lišily v závislosti na odrůdě. Senzorická analýza byla provedena pomocí kategorových ordinálních stupnic a profilového testu., The aim of this master‘s thesis was to determine the aroma active compounds and monitor the sensory quality of apples. The theoretical part deals with the description, composition and properties of apples, information about the aroma compounds, their determination and possibilities for sensory evaluation of apples is also given. The gas chromatography method combined with the solid-phase microextraction, utilized for the specification of aroma compounds, is described. In the experimental part, the SPME-GC-FID method was applied on selected cultivars of apples specially cultivated against apple scab (Venturia inaequalis), i.e. 24 genotypes and Golden Delicious as the control variety. In total 60 various aroma compounds were identified, 22 alcohols, 12 aldehydes, 11 ketones, 10 esters and 5 organic acids. The number and concentration of compounds identified differed according to the cultivars. Sensory analysis was performed using category ordinal scales and the profile test.