158 results on '"STENBERG, JOHAN A."'
Search Results
2. Updated pest risk assessment of Phytophthora ramorum in Norway:Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Thomsen, Iben Margrete, Alsanius, Beatrix, Flø, Daniel, Krokene, Paal, Wendell, Micael, Wright, Sandra A. I., Magnusson, Christer, Stenberg, Johan, Børve, Jorunn, Nybakken, Line, Nicolaisen, Mogens, Sæthre, May-Guri, Thomsen, Iben Margrete, Alsanius, Beatrix, Flø, Daniel, Krokene, Paal, Wendell, Micael, Wright, Sandra A. I., Magnusson, Christer, Stenberg, Johan, Børve, Jorunn, Nybakken, Line, Nicolaisen, Mogens, and Sæthre, May-Guri
- Published
- 2023
3. SLAGGBETONG OCH DESS HÅLLFASTHETUTVECKLING VID OLIKA HÄRDNINGSTEMPERATURER .
- Author
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Andersson, Oscar, Stenberg, Johan, Andersson, Oscar, and Stenberg, Johan
- Abstract
Bygg- och infrastruktursektorn präglas av betongkonstruktioner av diverse utformning där koldioxidutsläpp är ett känt problem hos betongindustrin. Bindemedlet cement utgör den största delen av koldioxidutsläppen, därav forskas det på alternativa material till cement där ett av de materialen är slagg. Att använda betong med höga ersättningsandelar av slagg är något som är möjligt under förutsättningar att forskning bedrivs, för att kunna säkerställa god funktion enligt standarder. Examensarbetet ämnar undersöka temperaturens inverkan vid härdningsprocessen. Examensarbetet möjliggjordes med hjälp av en litteraturstudie, dialog med Oskar Linderoth på Swerock samt via gjutning av betongkuber med vattenhärdning i laborationsmiljö. Hållfasthet testades med hydraulikpress på Örebro Universitet. De betongsammansättningar som gjöts hade 40% respektive 60% slagginblandning. Betongkuberna härdades i vattenbad i 20°C i inomhusklimat samt i 40°C i ett värmeskåp. Slutligen tryckprovades respektive betongsammansättning efter 3, 7 och 28 dygn. Totalt omfattade härdning och provtryckning 12 kuber. Resultaten visar att en högre härdningstemperatur medför en högre tryckhållfasthet mellan 3 och 28 dygn både vid 40% respektive 60% slagginblandning. I betongen med 40% slagginblandning ger den högre härdningstemperaturen initialt en högre hållfasthet, men den betongen med lägre härdningstemperatur sammanfaller med den högre efter 28 dygn. Den betongen med 60% slagginblandning har en mer parallell hållfasthetsutveckling mellan den lägre respektive högre härdningstemperaturen efter 3 och 28 dygn. Den högre härdningstemperaturen medför som tidigare en högre hållfasthet än den lägre härdningstemperaturen. Slutligen tyder resultaten på att en högre slagginblandning generellt medför en något lägre initial hållfasthet tidigt i härdningsprocessen, men att den kring 28 dygn har liknande eller högre hållfasthet än den betongen med mindre slagg. Slutsatsen är att Swerocks produkter visar tendenser, The construction and infrastructure sector consists of a lot of concrete structures where carbon dioxide emissions are a known problem in the concrete industry. The binder cement makes up the largest part of the carbon dioxide emissions, hence research is being done on alternative materials to cement and one of those materials is slag. Using concrete with high replacement proportions of slag is something that is possible under conditions that research is conducted, to ensure good function according to requirements. The thesis intends to investigate the effect of temperature in the curing process. The degree project was made possible with the help of a literature study, dialogue with Oskar Linderoth at Swerock and via casting of concrete cubes with water curing in a laboratory environment. Strength development was tested at Örebro University with a hydraulic press. The concrete compositions that were cast had 40% and 60% slag mixture, respectively. The concrete cubes were hardened in a water bath at 20°C in an indoor climate and at 40°C in a heating cabinet. Finally, the respective concrete composition was tested for strenght after 3, 7 and 28 days. In total, curing and casting comprised 12 cubes. The results show that a higher curing temperature results in a higher compressive strength between 3 and 28 days both at 40% and 60% slag mixture, respectively. In the concrete with 40% slag mixture, the higher curing temperature initially gives a higher strength, but the concrete with a lower curing temperature coincides with the higher one after 28 days. The concrete with 60% slag mixture has a more parallel strength development between the lower and higher curing temperature, respectively, after 3 and 28 days. As before, the higher curing temperature results in a higher strength than the lower curing temperature. Finally, the results indicate that a higher slag mixture generally results in a slightly lower initial strength early in the hardening process, but that it is
- Published
- 2022
4. SLAGGBETONG OCH DESS HÅLLFASTHETUTVECKLING VID OLIKA HÄRDNINGSTEMPERATURER .
- Author
-
Andersson, Oscar, Stenberg, Johan, Andersson, Oscar, and Stenberg, Johan
- Abstract
Bygg- och infrastruktursektorn präglas av betongkonstruktioner av diverse utformning där koldioxidutsläpp är ett känt problem hos betongindustrin. Bindemedlet cement utgör den största delen av koldioxidutsläppen, därav forskas det på alternativa material till cement där ett av de materialen är slagg. Att använda betong med höga ersättningsandelar av slagg är något som är möjligt under förutsättningar att forskning bedrivs, för att kunna säkerställa god funktion enligt standarder. Examensarbetet ämnar undersöka temperaturens inverkan vid härdningsprocessen. Examensarbetet möjliggjordes med hjälp av en litteraturstudie, dialog med Oskar Linderoth på Swerock samt via gjutning av betongkuber med vattenhärdning i laborationsmiljö. Hållfasthet testades med hydraulikpress på Örebro Universitet. De betongsammansättningar som gjöts hade 40% respektive 60% slagginblandning. Betongkuberna härdades i vattenbad i 20°C i inomhusklimat samt i 40°C i ett värmeskåp. Slutligen tryckprovades respektive betongsammansättning efter 3, 7 och 28 dygn. Totalt omfattade härdning och provtryckning 12 kuber. Resultaten visar att en högre härdningstemperatur medför en högre tryckhållfasthet mellan 3 och 28 dygn både vid 40% respektive 60% slagginblandning. I betongen med 40% slagginblandning ger den högre härdningstemperaturen initialt en högre hållfasthet, men den betongen med lägre härdningstemperatur sammanfaller med den högre efter 28 dygn. Den betongen med 60% slagginblandning har en mer parallell hållfasthetsutveckling mellan den lägre respektive högre härdningstemperaturen efter 3 och 28 dygn. Den högre härdningstemperaturen medför som tidigare en högre hållfasthet än den lägre härdningstemperaturen. Slutligen tyder resultaten på att en högre slagginblandning generellt medför en något lägre initial hållfasthet tidigt i härdningsprocessen, men att den kring 28 dygn har liknande eller högre hållfasthet än den betongen med mindre slagg. Slutsatsen är att Swerocks produkter visar tendenser, The construction and infrastructure sector consists of a lot of concrete structures where carbon dioxide emissions are a known problem in the concrete industry. The binder cement makes up the largest part of the carbon dioxide emissions, hence research is being done on alternative materials to cement and one of those materials is slag. Using concrete with high replacement proportions of slag is something that is possible under conditions that research is conducted, to ensure good function according to requirements. The thesis intends to investigate the effect of temperature in the curing process. The degree project was made possible with the help of a literature study, dialogue with Oskar Linderoth at Swerock and via casting of concrete cubes with water curing in a laboratory environment. Strength development was tested at Örebro University with a hydraulic press. The concrete compositions that were cast had 40% and 60% slag mixture, respectively. The concrete cubes were hardened in a water bath at 20°C in an indoor climate and at 40°C in a heating cabinet. Finally, the respective concrete composition was tested for strenght after 3, 7 and 28 days. In total, curing and casting comprised 12 cubes. The results show that a higher curing temperature results in a higher compressive strength between 3 and 28 days both at 40% and 60% slag mixture, respectively. In the concrete with 40% slag mixture, the higher curing temperature initially gives a higher strength, but the concrete with a lower curing temperature coincides with the higher one after 28 days. The concrete with 60% slag mixture has a more parallel strength development between the lower and higher curing temperature, respectively, after 3 and 28 days. As before, the higher curing temperature results in a higher strength than the lower curing temperature. Finally, the results indicate that a higher slag mixture generally results in a slightly lower initial strength early in the hardening process, but that it is
- Published
- 2022
5. Effects of strawberry resistance and genotypic diversity on aphids and their natural enemies
- Author
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Musaqaf, Nimra, Sigsgaard, Lene, Markussen, Bo, Stenberg, Johan A., Musaqaf, Nimra, Sigsgaard, Lene, Markussen, Bo, and Stenberg, Johan A.
- Abstract
Ecological theory hypothesizes that plant trait diversity may be as important as the presence of specific functional traits (e.g., resistance) for the herbivore and predator communities within a population. We used experimental populations of wild woodland strawberry (Fragaria vesca) to test whether the degree of plant genotypic diversity and/or the existence of specific resistance traits play a role in the host plant's community structure specifically, the community of generalist and specialist aphids and their natural enemies. In 2019, we studied the aphid abundance and relative predator abundance in an experimental field site in Alnarp, Southern Sweden; the field consisted of plots planted with combinations of 20 different wild strawberry genotypes. These strawberry genotypes were previously identified as either susceptible to or resistant against the herbivorous beetle (Galerucella tenella). Two aphid species, Chaetosiphon fragaefolii (specialist) and the exotic Aphis gossypii (generalist) were found in the plots and of the two species A. gossypii was dominant. The abundance of the specialist aphid (C. fragaefolii) was highest in susceptible plots with high genotypic diversity, while the generalist (A. gossypii) was highest in plots with a mix of resistant and susceptible plants with high genotypic diversity. Anthocorid predators, developed significantly higher population densities in strawberry plots with high genotypic diversity. Overall, predator abundance showed a positive correlation with aphid abundance. These results show that the specific functional trait of resistance as well as plant diversity affected aphids. Knowledge about these effects can be important factors to consider when designing strawberry plantings less susceptible to aphids.
- Published
- 2022
6. Effects of strawberry resistance and genotypic diversity on aphids and their natural enemies
- Author
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Musaqaf, Nimra, Sigsgaard, Lene, Markussen, Bo, Stenberg, Johan A., Musaqaf, Nimra, Sigsgaard, Lene, Markussen, Bo, and Stenberg, Johan A.
- Abstract
Ecological theory hypothesizes that plant trait diversity may be as important as the presence of specific functional traits (e.g., resistance) for the herbivore and predator communities within a population. We used experimental populations of wild woodland strawberry (Fragaria vesca) to test whether the degree of plant genotypic diversity and/or the existence of specific resistance traits play a role in the host plant's community structure specifically, the community of generalist and specialist aphids and their natural enemies. In 2019, we studied the aphid abundance and relative predator abundance in an experimental field site in Alnarp, Southern Sweden; the field consisted of plots planted with combinations of 20 different wild strawberry genotypes. These strawberry genotypes were previously identified as either susceptible to or resistant against the herbivorous beetle (Galerucella tenella). Two aphid species, Chaetosiphon fragaefolii (specialist) and the exotic Aphis gossypii (generalist) were found in the plots and of the two species A. gossypii was dominant. The abundance of the specialist aphid (C. fragaefolii) was highest in susceptible plots with high genotypic diversity, while the generalist (A. gossypii) was highest in plots with a mix of resistant and susceptible plants with high genotypic diversity. Anthocorid predators, developed significantly higher population densities in strawberry plots with high genotypic diversity. Overall, predator abundance showed a positive correlation with aphid abundance. These results show that the specific functional trait of resistance as well as plant diversity affected aphids. Knowledge about these effects can be important factors to consider when designing strawberry plantings less susceptible to aphids.
- Published
- 2022
7. Pollinators and herbivores interactively shape selection on strawberry defence and attraction
- Author
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Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., Stenberg, Johan A., Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
Tripartite interactions between plants, herbivores, and pollinators hold fitness consequences for most angiosperms. However, little is known on how plants evolve in response-and in particular what the net selective outcomes are for traits of shared relevance to pollinators and herbivores. In this study, we manipulated herbivory ("presence" and "absence" treatments) and pollination ("open" and "hand pollination" treatments) in a full factorial common-garden experiment with woodland strawberry (Fragaria vesca L.). This design allowed us to quantify the relative importance and interactive effects of herbivore- and pollinator-mediated selection on nine traits related to plant defence and attraction. Our results showed that pollinators imposed stronger selection than herbivores on traits related to both direct and indirect (i.e., tritrophic) defence. However, conflicting selection was imposed on inflorescence density: a trait that appears to be shared by herbivores and pollinators as a host plant signal. However, in all cases, selection imposed by one agent depended largely on the presence or ecological effect of the other, suggesting that dynamic patterns of selection could be a common outcome of these interactions in natural populations. As a whole, our findings highlight the significance of plant-herbivore-pollinator interactions as potential drivers of evolutionary change, and reveal that pollinators likely play an underappreciated role as selective agents on direct and in direct plant defence.
- Published
- 2021
- Full Text
- View/download PDF
8. Pollinators and herbivores interactively shape selection on strawberry defence and attraction
- Author
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Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., Stenberg, Johan A., Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
Tripartite interactions between plants, herbivores, and pollinators hold fitness consequences for most angiosperms. However, little is known on how plants evolve in response-and in particular what the net selective outcomes are for traits of shared relevance to pollinators and herbivores. In this study, we manipulated herbivory ("presence" and "absence" treatments) and pollination ("open" and "hand pollination" treatments) in a full factorial common-garden experiment with woodland strawberry (Fragaria vesca L.). This design allowed us to quantify the relative importance and interactive effects of herbivore- and pollinator-mediated selection on nine traits related to plant defence and attraction. Our results showed that pollinators imposed stronger selection than herbivores on traits related to both direct and indirect (i.e., tritrophic) defence. However, conflicting selection was imposed on inflorescence density: a trait that appears to be shared by herbivores and pollinators as a host plant signal. However, in all cases, selection imposed by one agent depended largely on the presence or ecological effect of the other, suggesting that dynamic patterns of selection could be a common outcome of these interactions in natural populations. As a whole, our findings highlight the significance of plant-herbivore-pollinator interactions as potential drivers of evolutionary change, and reveal that pollinators likely play an underappreciated role as selective agents on direct and in direct plant defence.
- Published
- 2021
- Full Text
- View/download PDF
9. Pollinators and herbivores interactively shape selection on strawberry defence and attraction
- Author
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Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., Stenberg, Johan A., Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
Tripartite interactions between plants, herbivores, and pollinators hold fitness consequences for most angiosperms. However, little is known on how plants evolve in response-and in particular what the net selective outcomes are for traits of shared relevance to pollinators and herbivores. In this study, we manipulated herbivory ("presence" and "absence" treatments) and pollination ("open" and "hand pollination" treatments) in a full factorial common-garden experiment with woodland strawberry (Fragaria vesca L.). This design allowed us to quantify the relative importance and interactive effects of herbivore- and pollinator-mediated selection on nine traits related to plant defence and attraction. Our results showed that pollinators imposed stronger selection than herbivores on traits related to both direct and indirect (i.e., tritrophic) defence. However, conflicting selection was imposed on inflorescence density: a trait that appears to be shared by herbivores and pollinators as a host plant signal. However, in all cases, selection imposed by one agent depended largely on the presence or ecological effect of the other, suggesting that dynamic patterns of selection could be a common outcome of these interactions in natural populations. As a whole, our findings highlight the significance of plant-herbivore-pollinator interactions as potential drivers of evolutionary change, and reveal that pollinators likely play an underappreciated role as selective agents on direct and in direct plant defence.
- Published
- 2021
- Full Text
- View/download PDF
10. Assessment of treatment methods and validation criteria for composting and biogas facilities in relation to plant health risks and the risk of spreading alien organisms : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, Rafoss, Trond, Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, and Rafoss, Trond
- Published
- 2021
11. Pollinators and herbivores interactively shape selection on strawberry defence and attraction
- Author
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Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., Stenberg, Johan A., Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
Tripartite interactions between plants, herbivores, and pollinators hold fitness consequences for most angiosperms. However, little is known on how plants evolve in response-and in particular what the net selective outcomes are for traits of shared relevance to pollinators and herbivores. In this study, we manipulated herbivory ("presence" and "absence" treatments) and pollination ("open" and "hand pollination" treatments) in a full factorial common-garden experiment with woodland strawberry (Fragaria vesca L.). This design allowed us to quantify the relative importance and interactive effects of herbivore- and pollinator-mediated selection on nine traits related to plant defence and attraction. Our results showed that pollinators imposed stronger selection than herbivores on traits related to both direct and indirect (i.e., tritrophic) defence. However, conflicting selection was imposed on inflorescence density: a trait that appears to be shared by herbivores and pollinators as a host plant signal. However, in all cases, selection imposed by one agent depended largely on the presence or ecological effect of the other, suggesting that dynamic patterns of selection could be a common outcome of these interactions in natural populations. As a whole, our findings highlight the significance of plant-herbivore-pollinator interactions as potential drivers of evolutionary change, and reveal that pollinators likely play an underappreciated role as selective agents on direct and in direct plant defence.
- Published
- 2021
- Full Text
- View/download PDF
12. Assessment of treatment methods and validation criteria for composting and biogas facilities in relation to plant health risks and the risk of spreading alien organisms : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, Rafoss, Trond, Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, and Rafoss, Trond
- Published
- 2021
13. Assessment of treatment methods and validation criteria for composting and biogas facilities in relation to plant health risks and the risk of spreading alien organisms : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, Rafoss, Trond, Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, and Rafoss, Trond
- Published
- 2021
14. Pest risk categorization – New plant health regulations for Norway : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Krokene, Paal, Hatteland, Bjørn Arild, Magnusson, Christer, Flø, Daniel, Thomsen, Iben M., Stenberg, Johan A., Brurberg, May Bente, Wendell, Micael, Nicolaisen, Mogens, Rossmann, Simeon, Talgø, Venche, Krokene, Paal, Hatteland, Bjørn Arild, Magnusson, Christer, Flø, Daniel, Thomsen, Iben M., Stenberg, Johan A., Brurberg, May Bente, Wendell, Micael, Nicolaisen, Mogens, Rossmann, Simeon, and Talgø, Venche
- Abstract
In an ongoing effort to renew Norwegian regulations related to plants and measures against plant pests, the Norwegian Food Safety Authority asked The Norwegian Scientific Committee for Food and Environment (VKM) which of the currently regulated pests that should still be regulated (either as a quarantine pest (QP) or a regulated non-quarantine pest (RNQP) for Norway), and whether there are any species that should be deregulated. Following such a risk categorization process the Norwegian Food Safety Authority will determine if pest risk assessments (PRA’s) should be performed for quarantine pests. International trade regulations define quarantine pests (QPs) as pests of potential economic importance to an area that are not yet present, or are present but not widely distributed and are subject to official control. A regulated non-quarantine pest (RNQP) is a pest whose presence in plants for planting affects the intended use of those plants with an economically unacceptable impact and which is therefore subject to official control within the territory of the importing contracting party and regulated in international trade. In this report VKM presents an overview of the pest categorisation of some of the pests regulated in the current Norwegian regulation and concludes on whether each pest should be regulated as a potential QP, RNQP or none of these categories for Norway. The pest categorisation process – the process of determining whether a pest has or has not the characteristics of a QP or RNQP – has been done using the FinnPRIO model. The FinnPRIO model is a pest risk ranking tool that uses a hypervolume approach carry out quick, semiquantitative expert assessments and that allows a high number of pest risk categorizations to be done cost-effectively and in a short period of time. In total 33 pests were assessed as per request from the Norwegian Food Safety Authority. Of those 33 pests VKM suggests that the vast majority – 32 pests – are kept as a QPs for Norway. How
- Published
- 2021
15. 'Resistance Mixtures' Reduce Insect Herbivory in Strawberry (Fragaria vesca) Plantings
- Author
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Koski, Tuuli-Marjaana, De Jong, Sanne, Muola, Anne, Amby, Daniel B., Andreasson, Erik, Stenberg, Johan A., Koski, Tuuli-Marjaana, De Jong, Sanne, Muola, Anne, Amby, Daniel B., Andreasson, Erik, and Stenberg, Johan A.
- Published
- 2021
16. Assessment of treatment methods and validation criteria for composting and biogas facilities in relation to plant health risks and the risk of spreading alien organisms : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, Rafoss, Trond, Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, and Rafoss, Trond
- Published
- 2021
17. Pollinators and herbivores interactively shape selection on strawberry defence and attraction
- Author
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Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., Stenberg, Johan A., Egan, Paul A., Muola, Anne, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
Tripartite interactions between plants, herbivores, and pollinators hold fitness consequences for most angiosperms. However, little is known on how plants evolve in response-and in particular what the net selective outcomes are for traits of shared relevance to pollinators and herbivores. In this study, we manipulated herbivory ("presence" and "absence" treatments) and pollination ("open" and "hand pollination" treatments) in a full factorial common-garden experiment with woodland strawberry (Fragaria vesca L.). This design allowed us to quantify the relative importance and interactive effects of herbivore- and pollinator-mediated selection on nine traits related to plant defence and attraction. Our results showed that pollinators imposed stronger selection than herbivores on traits related to both direct and indirect (i.e., tritrophic) defence. However, conflicting selection was imposed on inflorescence density: a trait that appears to be shared by herbivores and pollinators as a host plant signal. However, in all cases, selection imposed by one agent depended largely on the presence or ecological effect of the other, suggesting that dynamic patterns of selection could be a common outcome of these interactions in natural populations. As a whole, our findings highlight the significance of plant-herbivore-pollinator interactions as potential drivers of evolutionary change, and reveal that pollinators likely play an underappreciated role as selective agents on direct and in direct plant defence.
- Published
- 2021
- Full Text
- View/download PDF
18. Assessment of treatment methods and validation criteria for composting and biogas facilities in relation to plant health risks and the risk of spreading alien organisms : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
-
Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, Rafoss, Trond, Alsanius, Beatrix, Magnusson, Christer, Nicolaisen, Mogens, Wright, Sandra A. I., Wendell, Micael, Krokene, Paal, Stenberg, Johan, Thomsen, Iben M, and Rafoss, Trond
- Published
- 2021
19. 'Resistance Mixtures' Reduce Insect Herbivory in Strawberry (Fragaria vesca) Plantings
- Author
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Koski, Tuuli-Marjaana, De Jong, Sanne, Muola, Anne, Amby, Daniel B., Andreasson, Erik, Stenberg, Johan A., Koski, Tuuli-Marjaana, De Jong, Sanne, Muola, Anne, Amby, Daniel B., Andreasson, Erik, and Stenberg, Johan A.
- Published
- 2021
20. Plant resistance does not compromise parasitoid-based biocontrol of a strawberry pest
- Author
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Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., Stenberg, Johan A., Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., and Stenberg, Johan A.
- Abstract
Plant nutritional quality can influence interactions between herbivores and their parasitoids. While most previous work has focused on a limited set of secondary plant metabolites, the tri-trophic effects of overall phenotypic resistance have been understudied. Furthermore, the joint effects of secondary and primary metabolites on parasitoids are almost unexplored. In this study, we compared the performance and survival of the parasitoid species Asecodes parviclava Thompson on wild woodland strawberry (Fragaria vesca L.) genotypes showing variation in resistance against the parasitoid’s host, the strawberry leaf beetle (Galerucella tenella L.). Additionally, we related the metabolic profiles of these plant genotypes to the tritrophic outcomes in order to identify primary and secondary metabolites involved in regulating plant potential to facilitate parasitism. We found that parasitoid performance was strongly affected by plant genotype, but those differences in plant resistance to the herbivore were not reflected in parasitoid survival. These findings could be explained in particular by a significant link between parasitoid survival and foliar carbohydrate levels, which appeared to be the most important compounds for parasitism success. The fact that plant quality strongly affects parasitism should be further explored and utilized in plant breeding programs for a synergistic application in sustainable pest management.
- Published
- 2020
- Full Text
- View/download PDF
21. Plant resistance does not compromise parasitoid-based biocontrol of a strawberry pest
- Author
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Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., Stenberg, Johan A., Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., and Stenberg, Johan A.
- Abstract
Plant nutritional quality can influence interactions between herbivores and their parasitoids. While most previous work has focused on a limited set of secondary plant metabolites, the tri-trophic effects of overall phenotypic resistance have been understudied. Furthermore, the joint effects of secondary and primary metabolites on parasitoids are almost unexplored. In this study, we compared the performance and survival of the parasitoid species Asecodes parviclava Thompson on wild woodland strawberry (Fragaria vesca L.) genotypes showing variation in resistance against the parasitoid’s host, the strawberry leaf beetle (Galerucella tenella L.). Additionally, we related the metabolic profiles of these plant genotypes to the tritrophic outcomes in order to identify primary and secondary metabolites involved in regulating plant potential to facilitate parasitism. We found that parasitoid performance was strongly affected by plant genotype, but those differences in plant resistance to the herbivore were not reflected in parasitoid survival. These findings could be explained in particular by a significant link between parasitoid survival and foliar carbohydrate levels, which appeared to be the most important compounds for parasitism success. The fact that plant quality strongly affects parasitism should be further explored and utilized in plant breeding programs for a synergistic application in sustainable pest management.
- Published
- 2020
- Full Text
- View/download PDF
22. Plant resistance does not compromise parasitoid-based biocontrol of a strawberry pest
- Author
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Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., Stenberg, Johan A., Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., and Stenberg, Johan A.
- Abstract
Plant nutritional quality can influence interactions between herbivores and their parasitoids. While most previous work has focused on a limited set of secondary plant metabolites, the tri-trophic effects of overall phenotypic resistance have been understudied. Furthermore, the joint effects of secondary and primary metabolites on parasitoids are almost unexplored. In this study, we compared the performance and survival of the parasitoid species Asecodes parviclava Thompson on wild woodland strawberry (Fragaria vesca L.) genotypes showing variation in resistance against the parasitoid’s host, the strawberry leaf beetle (Galerucella tenella L.). Additionally, we related the metabolic profiles of these plant genotypes to the tritrophic outcomes in order to identify primary and secondary metabolites involved in regulating plant potential to facilitate parasitism. We found that parasitoid performance was strongly affected by plant genotype, but those differences in plant resistance to the herbivore were not reflected in parasitoid survival. These findings could be explained in particular by a significant link between parasitoid survival and foliar carbohydrate levels, which appeared to be the most important compounds for parasitism success. The fact that plant quality strongly affects parasitism should be further explored and utilized in plant breeding programs for a synergistic application in sustainable pest management.
- Published
- 2020
- Full Text
- View/download PDF
23. Risk assessment of the biological control product Atheta-System with the organism Atheta coriaria Kraatz : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Stenberg, Johan A., Nielsen, Anders, Stenberg, Johan A., and Nielsen, Anders
- Abstract
Atheta-System with the rove beetle Atheta coriaria (Kraatz 1856) as the active organism is sought to be used as a biocontrol agent for augmentation biological control in Norway. Atheta-System is intended for use against soil dwelling stages of fungus gnats (e.g. Bradysiapaupera), shore flies (Scatella stagnalis), and thrips (e.g. Frankliniella occidentallis) in greenhouses, plastic tunnels, and other closed or controlled climate cultivations of horticultural crops, incl. soft-fruit crops, vegetables, ornamentals, and kitchen herbs.
- Published
- 2020
24. Risk assessment of the biological control product Limonica with the organism Amblydromalus limonicus : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Nielsen, Anders, Stenberg, Johan A., Wendell, Micael, Nielsen, Anders, Stenberg, Johan A., and Wendell, Micael
- Abstract
The product Limonica, with the predatory mite Amblydromalus limonicus as the active organism, is sought to be used as a biological control agent in Norway. Limonica is intended for use against western flower thrips (Frankliniella occidentallis), other thrips (e.g. Thripstabaci), spider mites and white flies (e.g. Trialeurodes, Aleyrodes and Bemisia spp.) in protected horticultural crops such as cucumber, sweet pepper, strawberry and ornamentals. The product is not recommended for greenhouse-grown tomatoes.
- Published
- 2020
25. Risk assessment of the biological control product ANDERcontrol with the organism Amblyseius andersoni : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Stenberg, Johan A., Nielsen, Anders, Wendell, Micael, Stenberg, Johan A., Nielsen, Anders, and Wendell, Micael
- Abstract
ANDERcontrol with the predatory mite Amblyseius andersoni as the active organism is sought to be used as a biological control agent in Norway. ANDERcontrol is intended for use against different mites (such as the two-spotted, fruit-tree, and red spider mite, russetmite, cyclamen mite) and in horticultural crops such as fruits, berries, vegetables, and ornamental.
- Published
- 2020
26. Plant resistance does not compromise parasitoid-based biocontrol of a strawberry pest
- Author
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Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., Stenberg, Johan A., Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., and Stenberg, Johan A.
- Abstract
Plant nutritional quality can influence interactions between herbivores and their parasitoids. While most previous work has focused on a limited set of secondary plant metabolites, the tri-trophic effects of overall phenotypic resistance have been understudied. Furthermore, the joint effects of secondary and primary metabolites on parasitoids are almost unexplored. In this study, we compared the performance and survival of the parasitoid species Asecodes parviclava Thompson on wild woodland strawberry (Fragaria vesca L.) genotypes showing variation in resistance against the parasitoid’s host, the strawberry leaf beetle (Galerucella tenella L.). Additionally, we related the metabolic profiles of these plant genotypes to the tritrophic outcomes in order to identify primary and secondary metabolites involved in regulating plant potential to facilitate parasitism. We found that parasitoid performance was strongly affected by plant genotype, but those differences in plant resistance to the herbivore were not reflected in parasitoid survival. These findings could be explained in particular by a significant link between parasitoid survival and foliar carbohydrate levels, which appeared to be the most important compounds for parasitism success. The fact that plant quality strongly affects parasitism should be further explored and utilized in plant breeding programs for a synergistic application in sustainable pest management.
- Published
- 2020
- Full Text
- View/download PDF
27. Plant resistance does not compromise parasitoid-based biocontrol of a strawberry pest
- Author
-
Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., Stenberg, Johan A., Weber, Daniela, Egan, Paul A., Muola, Anne, Ericson, Lars E., and Stenberg, Johan A.
- Abstract
Plant nutritional quality can influence interactions between herbivores and their parasitoids. While most previous work has focused on a limited set of secondary plant metabolites, the tri-trophic effects of overall phenotypic resistance have been understudied. Furthermore, the joint effects of secondary and primary metabolites on parasitoids are almost unexplored. In this study, we compared the performance and survival of the parasitoid species Asecodes parviclava Thompson on wild woodland strawberry (Fragaria vesca L.) genotypes showing variation in resistance against the parasitoid’s host, the strawberry leaf beetle (Galerucella tenella L.). Additionally, we related the metabolic profiles of these plant genotypes to the tritrophic outcomes in order to identify primary and secondary metabolites involved in regulating plant potential to facilitate parasitism. We found that parasitoid performance was strongly affected by plant genotype, but those differences in plant resistance to the herbivore were not reflected in parasitoid survival. These findings could be explained in particular by a significant link between parasitoid survival and foliar carbohydrate levels, which appeared to be the most important compounds for parasitism success. The fact that plant quality strongly affects parasitism should be further explored and utilized in plant breeding programs for a synergistic application in sustainable pest management.
- Published
- 2020
- Full Text
- View/download PDF
28. Pest risk assessment of selected Epitrix species : Scientific Opinion of the Panel on Plant Health of the Norwegian Scientific Committee for Food and Environment
- Author
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Stenberg, Johan A., Flø, Daniel, Kirkendall, Lawrence, Krokene, Paal, Stenberg, Johan A., Flø, Daniel, Kirkendall, Lawrence, and Krokene, Paal
- Abstract
Epitrix is a taxonomically complex genus, with 162 described species all over the world, and most likely many more undescribed species. Due to taxonomic difficulties identifying the species, there is considerable uncertainty regarding which species that feed on cultivated crops. At least 13 Epitrix species are known to damage the tubers of potato, which is the crop of concern in northern Europe. At least five of those Epitrix species (E. hirtipennis, E. fasciata, E.cucumeris, E. papa and E. pubescens) have established themselves outside their native range, spurring concerns that they may spread further and potentially cause damage in new areas where potato is cultivated. It is unknown how most of these species have moved from country to country, but there have been several interceptions of unknown Epitrix species in shipments of ware potatoes.
- Published
- 2019
29. Is there a best woodland strawberry (Fragaria vesca)? : a consumer survey of preferred sensory properties and cultivation characteristics of woodland strawberries
- Author
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Wendin, Karin, Egan, Paul, Olsson, Viktoria, Forsberg, Sarah, Nilsson, Annika, Stenberg, Johan, Wendin, Karin, Egan, Paul, Olsson, Viktoria, Forsberg, Sarah, Nilsson, Annika, and Stenberg, Johan
- Abstract
In order to guide strawberry breeders, consumers' preferences and attitudes regarding fruit traits and cultivation practices were investigated. Differences and similarities between consumers of different age and gender were also explored. Consumer data from a total of 176 Swedish respondents showed that the most important factors influencing the consumers' preferences were the characteristic flavour of the woodland strawberry, the sweetness and the naturalness. Regarding visual appearance, it was shown that colour intensity, roundness and seed density could explain why the consumers' preferences for the fruits varied. These results may guide the breeding of new strawberry cultivars in the future., Multi functional resistance : a key to i ntegrated pest management, pollination, and fruit quality
- Published
- 2019
- Full Text
- View/download PDF
30. Roe deer prefer mixed-sex willow stands over monosexual stands but do not discriminate between male and female plants
- Author
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Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., Stenberg, Johan A., Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., and Stenberg, Johan A.
- Abstract
Male and female plants of dioecious species often experience differential herbivory, possibly due to differences in defences such as secondary metabolite composition or nutritional quality. These plant sex effects on herbivory have been extensively studied for plant individuals, but not for stands/populations. For mobile herbivores, such as deer, stands may be a more relevant scale to study than individual plants. We predicted that male Salts viminalis plants should be subject to more extensive roe deer (Capreolus capreolus) browsing than female plants due to weaker defence in male plants. Furthermore, we expected that mixed-sex stands should experience more damage than monosexual stands due to positive effects of diet mixing on browsing by generalists. We tested for differences in roe deer browsing in plots that were either monosexual male or female, or a mix of male and female plants in a replicated field experiment. Roe deer browsing was estimated after one growth season with heavy herbivory. We also measured plant secondary metabolite concentrations and nitrogen content in leaves from all experimental clones to test the assumption that the sexes differed in defence or nutrients. Mixed-sex plots were more extensively browsed than monosexual plots. However, there was no difference in browsing between male and female plant individuals within mixed-sex plots or between monosexual plots. Plant secondary metabolite profiles differed between male and female plants, while nitrogen content did not. Our findings suggest that the diversified plant secondary metabolite contents of mixed-sex plots may have led to more extensive herbivory. Higher browsing of plant sex mixes may impact both natural and commercial S. viminalis stands with different sex ratios.
- Published
- 2018
- Full Text
- View/download PDF
31. Is there a best woodland strawberry (Fragaria vesca)? : a consumer survey of preferred sensory properties and cultivation characteristics of woodland strawberries
- Author
-
Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, Stenberg, Johan, Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, and Stenberg, Johan
- Abstract
Introduction Resistant varieties are important to combat agricultural pathogens and pests in strawberry and other crops. Consequently, plant breeders aim to develop crop varieties with higher resistance in order to increase sustainability. However, plant resistance may affect quality, e.g. sensory properties of the fruits, and thereby consumer acceptance. The development of new varieties may also affect consumer attitudes. The purpose of this study was to investigate consumers’ preferences and attitudes regarding woodland strawberry. Methods Consumer data from a total number of 176 (78% women and 22% men, >18 years) Swedish respondents were collected via a web based survey during two weeks in September 2017. Data were processed using descriptive and analytical statistics. Results The most preferred fruits have a significant flavor of woodland strawberry and are high in sweetness. Further, “naturalness” and “free from pesticides” were of importance to the respondents. Women were significantly more concerned of “naturalness”, especially the older women. The younger claimed that “organic production” was more important. The older consumers were significantly more interested in “healthiness” than the younger, they also found it significantly more important than the younger that strawberries could resist grey mould and pest insects. All the respondents preferred to eat strawberries fresh. Discussion In line with earlier studies, taste and flavor are the most preferred properties for consumers. In woodland strawberry, the compound methyl anthranilate is responsible for the characteristic flavor of the fruit, together with sweetness from saccharides. However, also in accordance with earlier studies, factors such as naturalness, healthiness and organic production are of greatest importance to the consumer. Though it was also apparent that different consumer groups prioritized different factors. However, common for all respondents was a strong preference to eat stra, Multifunctional resistance : a key to integrated pest management, pollination, and fruit quality
- Published
- 2018
32. Roe deer prefer mixed-sex willow stands over monosexual stands but do not discriminate between male and female plants
- Author
-
Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., Stenberg, Johan A., Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., and Stenberg, Johan A.
- Abstract
Male and female plants of dioecious species often experience differential herbivory, possibly due to differences in defences such as secondary metabolite composition or nutritional quality. These plant sex effects on herbivory have been extensively studied for plant individuals, but not for stands/populations. For mobile herbivores, such as deer, stands may be a more relevant scale to study than individual plants. We predicted that male Salts viminalis plants should be subject to more extensive roe deer (Capreolus capreolus) browsing than female plants due to weaker defence in male plants. Furthermore, we expected that mixed-sex stands should experience more damage than monosexual stands due to positive effects of diet mixing on browsing by generalists. We tested for differences in roe deer browsing in plots that were either monosexual male or female, or a mix of male and female plants in a replicated field experiment. Roe deer browsing was estimated after one growth season with heavy herbivory. We also measured plant secondary metabolite concentrations and nitrogen content in leaves from all experimental clones to test the assumption that the sexes differed in defence or nutrients. Mixed-sex plots were more extensively browsed than monosexual plots. However, there was no difference in browsing between male and female plant individuals within mixed-sex plots or between monosexual plots. Plant secondary metabolite profiles differed between male and female plants, while nitrogen content did not. Our findings suggest that the diversified plant secondary metabolite contents of mixed-sex plots may have led to more extensive herbivory. Higher browsing of plant sex mixes may impact both natural and commercial S. viminalis stands with different sex ratios.
- Published
- 2018
- Full Text
- View/download PDF
33. Roe deer prefer mixed-sex willow stands over monosexual stands but do not discriminate between male and female plants
- Author
-
Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., Stenberg, Johan A., Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., and Stenberg, Johan A.
- Abstract
Male and female plants of dioecious species often experience differential herbivory, possibly due to differences in defences such as secondary metabolite composition or nutritional quality. These plant sex effects on herbivory have been extensively studied for plant individuals, but not for stands/populations. For mobile herbivores, such as deer, stands may be a more relevant scale to study than individual plants. We predicted that male Salts viminalis plants should be subject to more extensive roe deer (Capreolus capreolus) browsing than female plants due to weaker defence in male plants. Furthermore, we expected that mixed-sex stands should experience more damage than monosexual stands due to positive effects of diet mixing on browsing by generalists. We tested for differences in roe deer browsing in plots that were either monosexual male or female, or a mix of male and female plants in a replicated field experiment. Roe deer browsing was estimated after one growth season with heavy herbivory. We also measured plant secondary metabolite concentrations and nitrogen content in leaves from all experimental clones to test the assumption that the sexes differed in defence or nutrients. Mixed-sex plots were more extensively browsed than monosexual plots. However, there was no difference in browsing between male and female plant individuals within mixed-sex plots or between monosexual plots. Plant secondary metabolite profiles differed between male and female plants, while nitrogen content did not. Our findings suggest that the diversified plant secondary metabolite contents of mixed-sex plots may have led to more extensive herbivory. Higher browsing of plant sex mixes may impact both natural and commercial S. viminalis stands with different sex ratios.
- Published
- 2018
- Full Text
- View/download PDF
34. Is there a best woodland strawberry (Fragaria vesca)? : a consumer survey of preferred sensory properties and cultivation characteristics of woodland strawberries
- Author
-
Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, Stenberg, Johan, Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, and Stenberg, Johan
- Abstract
Introduction Resistant varieties are important to combat agricultural pathogens and pests in strawberry and other crops. Consequently, plant breeders aim to develop crop varieties with higher resistance in order to increase sustainability. However, plant resistance may affect quality, e.g. sensory properties of the fruits, and thereby consumer acceptance. The development of new varieties may also affect consumer attitudes. The purpose of this study was to investigate consumers’ preferences and attitudes regarding woodland strawberry. Methods Consumer data from a total number of 176 (78% women and 22% men, >18 years) Swedish respondents were collected via a web based survey during two weeks in September 2017. Data were processed using descriptive and analytical statistics. Results The most preferred fruits have a significant flavor of woodland strawberry and are high in sweetness. Further, “naturalness” and “free from pesticides” were of importance to the respondents. Women were significantly more concerned of “naturalness”, especially the older women. The younger claimed that “organic production” was more important. The older consumers were significantly more interested in “healthiness” than the younger, they also found it significantly more important than the younger that strawberries could resist grey mould and pest insects. All the respondents preferred to eat strawberries fresh. Discussion In line with earlier studies, taste and flavor are the most preferred properties for consumers. In woodland strawberry, the compound methyl anthranilate is responsible for the characteristic flavor of the fruit, together with sweetness from saccharides. However, also in accordance with earlier studies, factors such as naturalness, healthiness and organic production are of greatest importance to the consumer. Though it was also apparent that different consumer groups prioritized different factors. However, common for all respondents was a strong preference to eat stra, Multifunctional resistance : a key to integrated pest management, pollination, and fruit quality
- Published
- 2018
35. Roe deer prefer mixed-sex willow stands over monosexual stands but do not discriminate between male and female plants
- Author
-
Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., Stenberg, Johan A., Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., and Stenberg, Johan A.
- Abstract
Male and female plants of dioecious species often experience differential herbivory, possibly due to differences in defences such as secondary metabolite composition or nutritional quality. These plant sex effects on herbivory have been extensively studied for plant individuals, but not for stands/populations. For mobile herbivores, such as deer, stands may be a more relevant scale to study than individual plants. We predicted that male Salts viminalis plants should be subject to more extensive roe deer (Capreolus capreolus) browsing than female plants due to weaker defence in male plants. Furthermore, we expected that mixed-sex stands should experience more damage than monosexual stands due to positive effects of diet mixing on browsing by generalists. We tested for differences in roe deer browsing in plots that were either monosexual male or female, or a mix of male and female plants in a replicated field experiment. Roe deer browsing was estimated after one growth season with heavy herbivory. We also measured plant secondary metabolite concentrations and nitrogen content in leaves from all experimental clones to test the assumption that the sexes differed in defence or nutrients. Mixed-sex plots were more extensively browsed than monosexual plots. However, there was no difference in browsing between male and female plant individuals within mixed-sex plots or between monosexual plots. Plant secondary metabolite profiles differed between male and female plants, while nitrogen content did not. Our findings suggest that the diversified plant secondary metabolite contents of mixed-sex plots may have led to more extensive herbivory. Higher browsing of plant sex mixes may impact both natural and commercial S. viminalis stands with different sex ratios.
- Published
- 2018
- Full Text
- View/download PDF
36. Is there a best woodland strawberry (Fragaria vesca)? : a consumer survey of preferred sensory properties and cultivation characteristics of woodland strawberries
- Author
-
Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, Stenberg, Johan, Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, and Stenberg, Johan
- Abstract
Introduction Resistant varieties are important to combat agricultural pathogens and pests in strawberry and other crops. Consequently, plant breeders aim to develop crop varieties with higher resistance in order to increase sustainability. However, plant resistance may affect quality, e.g. sensory properties of the fruits, and thereby consumer acceptance. The development of new varieties may also affect consumer attitudes. The purpose of this study was to investigate consumers’ preferences and attitudes regarding woodland strawberry. Methods Consumer data from a total number of 176 (78% women and 22% men, >18 years) Swedish respondents were collected via a web based survey during two weeks in September 2017. Data were processed using descriptive and analytical statistics. Results The most preferred fruits have a significant flavor of woodland strawberry and are high in sweetness. Further, “naturalness” and “free from pesticides” were of importance to the respondents. Women were significantly more concerned of “naturalness”, especially the older women. The younger claimed that “organic production” was more important. The older consumers were significantly more interested in “healthiness” than the younger, they also found it significantly more important than the younger that strawberries could resist grey mould and pest insects. All the respondents preferred to eat strawberries fresh. Discussion In line with earlier studies, taste and flavor are the most preferred properties for consumers. In woodland strawberry, the compound methyl anthranilate is responsible for the characteristic flavor of the fruit, together with sweetness from saccharides. However, also in accordance with earlier studies, factors such as naturalness, healthiness and organic production are of greatest importance to the consumer. Though it was also apparent that different consumer groups prioritized different factors. However, common for all respondents was a strong preference to eat stra, Multifunctional resistance : a key to integrated pest management, pollination, and fruit quality
- Published
- 2018
37. Is there a best woodland strawberry (Fragaria vesca)? : a consumer survey of preferred sensory properties and cultivation characteristics of woodland strawberries
- Author
-
Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, Stenberg, Johan, Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, and Stenberg, Johan
- Abstract
Introduction Resistant varieties are important to combat agricultural pathogens and pests in strawberry and other crops. Consequently, plant breeders aim to develop crop varieties with higher resistance in order to increase sustainability. However, plant resistance may affect quality, e.g. sensory properties of the fruits, and thereby consumer acceptance. The development of new varieties may also affect consumer attitudes. The purpose of this study was to investigate consumers’ preferences and attitudes regarding woodland strawberry. Methods Consumer data from a total number of 176 (78% women and 22% men, >18 years) Swedish respondents were collected via a web based survey during two weeks in September 2017. Data were processed using descriptive and analytical statistics. Results The most preferred fruits have a significant flavor of woodland strawberry and are high in sweetness. Further, “naturalness” and “free from pesticides” were of importance to the respondents. Women were significantly more concerned of “naturalness”, especially the older women. The younger claimed that “organic production” was more important. The older consumers were significantly more interested in “healthiness” than the younger, they also found it significantly more important than the younger that strawberries could resist grey mould and pest insects. All the respondents preferred to eat strawberries fresh. Discussion In line with earlier studies, taste and flavor are the most preferred properties for consumers. In woodland strawberry, the compound methyl anthranilate is responsible for the characteristic flavor of the fruit, together with sweetness from saccharides. However, also in accordance with earlier studies, factors such as naturalness, healthiness and organic production are of greatest importance to the consumer. Though it was also apparent that different consumer groups prioritized different factors. However, common for all respondents was a strong preference to eat stra, Multifunctional resistance : a key to integrated pest management, pollination, and fruit quality
- Published
- 2018
38. Roe deer prefer mixed-sex willow stands over monosexual stands but do not discriminate between male and female plants
- Author
-
Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., Stenberg, Johan A., Moritz, Kim K., Parachnowitsch, Amy L., Julkunen-Tiitto, Riitta, Björkman, Christer, Ayres, Matthew P., and Stenberg, Johan A.
- Abstract
Male and female plants of dioecious species often experience differential herbivory, possibly due to differences in defences such as secondary metabolite composition or nutritional quality. These plant sex effects on herbivory have been extensively studied for plant individuals, but not for stands/populations. For mobile herbivores, such as deer, stands may be a more relevant scale to study than individual plants. We predicted that male Salts viminalis plants should be subject to more extensive roe deer (Capreolus capreolus) browsing than female plants due to weaker defence in male plants. Furthermore, we expected that mixed-sex stands should experience more damage than monosexual stands due to positive effects of diet mixing on browsing by generalists. We tested for differences in roe deer browsing in plots that were either monosexual male or female, or a mix of male and female plants in a replicated field experiment. Roe deer browsing was estimated after one growth season with heavy herbivory. We also measured plant secondary metabolite concentrations and nitrogen content in leaves from all experimental clones to test the assumption that the sexes differed in defence or nutrients. Mixed-sex plots were more extensively browsed than monosexual plots. However, there was no difference in browsing between male and female plant individuals within mixed-sex plots or between monosexual plots. Plant secondary metabolite profiles differed between male and female plants, while nitrogen content did not. Our findings suggest that the diversified plant secondary metabolite contents of mixed-sex plots may have led to more extensive herbivory. Higher browsing of plant sex mixes may impact both natural and commercial S. viminalis stands with different sex ratios.
- Published
- 2018
- Full Text
- View/download PDF
39. Is there a best woodland strawberry (Fragaria vesca)? : a consumer survey of preferred sensory properties and cultivation characteristics of woodland strawberries
- Author
-
Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, Stenberg, Johan, Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, and Stenberg, Johan
- Abstract
Introduction Resistant varieties are important to combat agricultural pathogens and pests in strawberry and other crops. Consequently, plant breeders aim to develop crop varieties with higher resistance in order to increase sustainability. However, plant resistance may affect quality, e.g. sensory properties of the fruits, and thereby consumer acceptance. The development of new varieties may also affect consumer attitudes. The purpose of this study was to investigate consumers’ preferences and attitudes regarding woodland strawberry. Methods Consumer data from a total number of 176 (78% women and 22% men, >18 years) Swedish respondents were collected via a web based survey during two weeks in September 2017. Data were processed using descriptive and analytical statistics. Results The most preferred fruits have a significant flavor of woodland strawberry and are high in sweetness. Further, “naturalness” and “free from pesticides” were of importance to the respondents. Women were significantly more concerned of “naturalness”, especially the older women. The younger claimed that “organic production” was more important. The older consumers were significantly more interested in “healthiness” than the younger, they also found it significantly more important than the younger that strawberries could resist grey mould and pest insects. All the respondents preferred to eat strawberries fresh. Discussion In line with earlier studies, taste and flavor are the most preferred properties for consumers. In woodland strawberry, the compound methyl anthranilate is responsible for the characteristic flavor of the fruit, together with sweetness from saccharides. However, also in accordance with earlier studies, factors such as naturalness, healthiness and organic production are of greatest importance to the consumer. Though it was also apparent that different consumer groups prioritized different factors. However, common for all respondents was a strong preference to eat stra, Multifunctional resistance : a key to integrated pest management, pollination, and fruit quality
- Published
- 2018
40. Is there a best woodland strawberry (Fragaria vesca)? : a consumer survey of preferred sensory properties and cultivation characteristics of woodland strawberries
- Author
-
Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, Stenberg, Johan, Wendin, Karin, Forsberg, Sarah, Olsson, Viktoria, Nilsson, Annika, Egan, Paul, and Stenberg, Johan
- Abstract
Introduction Resistant varieties are important to combat agricultural pathogens and pests in strawberry and other crops. Consequently, plant breeders aim to develop crop varieties with higher resistance in order to increase sustainability. However, plant resistance may affect quality, e.g. sensory properties of the fruits, and thereby consumer acceptance. The development of new varieties may also affect consumer attitudes. The purpose of this study was to investigate consumers’ preferences and attitudes regarding woodland strawberry. Methods Consumer data from a total number of 176 (78% women and 22% men, >18 years) Swedish respondents were collected via a web based survey during two weeks in September 2017. Data were processed using descriptive and analytical statistics. Results The most preferred fruits have a significant flavor of woodland strawberry and are high in sweetness. Further, “naturalness” and “free from pesticides” were of importance to the respondents. Women were significantly more concerned of “naturalness”, especially the older women. The younger claimed that “organic production” was more important. The older consumers were significantly more interested in “healthiness” than the younger, they also found it significantly more important than the younger that strawberries could resist grey mould and pest insects. All the respondents preferred to eat strawberries fresh. Discussion In line with earlier studies, taste and flavor are the most preferred properties for consumers. In woodland strawberry, the compound methyl anthranilate is responsible for the characteristic flavor of the fruit, together with sweetness from saccharides. However, also in accordance with earlier studies, factors such as naturalness, healthiness and organic production are of greatest importance to the consumer. Though it was also apparent that different consumer groups prioritized different factors. However, common for all respondents was a strong preference to eat stra, Multifunctional resistance : a key to integrated pest management, pollination, and fruit quality
- Published
- 2018
41. Plant sex effects on insect herbivores and biological control in a Short Rotation Coppice willow
- Author
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Moritz, Kim K., Bjorkman, Christer, Parachnowitsch, Amy L., Stenberg, Johan A., Moritz, Kim K., Bjorkman, Christer, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
In the wild, plant sex can affect plant-herbivore interactions and higher trophic levels, including natural enemies of the herbivores. However, the possibility of manipulating plant sex to improve biological control and reduce herbivory in domesticated dioecious crops remains unexplored. The dioecious bioenergy crop, Salix viminalis, is often planted in monoclonal, and thus monosexual, fields. We investigated whether using plant clones of either sex, or mixing plants of both sexes, reduced the performance and abundance of the herbivorous pest insect Phratora vulgatissima and its main natural enemy, Anthocoris nemorum, and whether predation was affected. The herbivore laid more eggs, and the predator survived longer, on female plants in the lab. However, these effects did not translate into differences in predation rates in laboratory experiments or differential insect abundances on plants of either sex or plantation sex composition in the field. Plant genotype did have a significant effect on insect abundances, but this was due to plant traits other than sex. The results indicate that manipulating plant sex will not lead to improved biological control or reduced insect herbivory in S. viminalis energy forestry, but suggest that a focus on plant genotypic differences offers promise for improving management practices.
- Published
- 2017
- Full Text
- View/download PDF
42. Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance
- Author
-
Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., Stenberg, Johan A., Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rugen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.
- Published
- 2017
- Full Text
- View/download PDF
43. Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance
- Author
-
Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., Stenberg, Johan A., Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rugen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.
- Published
- 2017
- Full Text
- View/download PDF
44. Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance
- Author
-
Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., Stenberg, Johan A., Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rugen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.
- Published
- 2017
- Full Text
- View/download PDF
45. Plant sex effects on insect herbivores and biological control in a Short Rotation Coppice willow
- Author
-
Moritz, Kim K., Bjorkman, Christer, Parachnowitsch, Amy L., Stenberg, Johan A., Moritz, Kim K., Bjorkman, Christer, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
In the wild, plant sex can affect plant-herbivore interactions and higher trophic levels, including natural enemies of the herbivores. However, the possibility of manipulating plant sex to improve biological control and reduce herbivory in domesticated dioecious crops remains unexplored. The dioecious bioenergy crop, Salix viminalis, is often planted in monoclonal, and thus monosexual, fields. We investigated whether using plant clones of either sex, or mixing plants of both sexes, reduced the performance and abundance of the herbivorous pest insect Phratora vulgatissima and its main natural enemy, Anthocoris nemorum, and whether predation was affected. The herbivore laid more eggs, and the predator survived longer, on female plants in the lab. However, these effects did not translate into differences in predation rates in laboratory experiments or differential insect abundances on plants of either sex or plantation sex composition in the field. Plant genotype did have a significant effect on insect abundances, but this was due to plant traits other than sex. The results indicate that manipulating plant sex will not lead to improved biological control or reduced insect herbivory in S. viminalis energy forestry, but suggest that a focus on plant genotypic differences offers promise for improving management practices.
- Published
- 2017
- Full Text
- View/download PDF
46. Plant sex effects on insect herbivores and biological control in a Short Rotation Coppice willow
- Author
-
Moritz, Kim K., Bjorkman, Christer, Parachnowitsch, Amy L., Stenberg, Johan A., Moritz, Kim K., Bjorkman, Christer, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
In the wild, plant sex can affect plant-herbivore interactions and higher trophic levels, including natural enemies of the herbivores. However, the possibility of manipulating plant sex to improve biological control and reduce herbivory in domesticated dioecious crops remains unexplored. The dioecious bioenergy crop, Salix viminalis, is often planted in monoclonal, and thus monosexual, fields. We investigated whether using plant clones of either sex, or mixing plants of both sexes, reduced the performance and abundance of the herbivorous pest insect Phratora vulgatissima and its main natural enemy, Anthocoris nemorum, and whether predation was affected. The herbivore laid more eggs, and the predator survived longer, on female plants in the lab. However, these effects did not translate into differences in predation rates in laboratory experiments or differential insect abundances on plants of either sex or plantation sex composition in the field. Plant genotype did have a significant effect on insect abundances, but this was due to plant traits other than sex. The results indicate that manipulating plant sex will not lead to improved biological control or reduced insect herbivory in S. viminalis energy forestry, but suggest that a focus on plant genotypic differences offers promise for improving management practices.
- Published
- 2017
- Full Text
- View/download PDF
47. Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance
- Author
-
Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., Stenberg, Johan A., Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rügen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.
- Published
- 2017
- Full Text
- View/download PDF
48. Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance
- Author
-
Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., Stenberg, Johan A., Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rügen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.
- Published
- 2017
- Full Text
- View/download PDF
49. Direct and Pollinator-Mediated Effects of Herbivory on Strawberry and the Potential for Improved Resistance
- Author
-
Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., Stenberg, Johan A., Muola, Anne, Weber, Daniela, Malm, Lisa E., Egan, Paul A., Glinwood, Robert, Parachnowitsch, Amy L., and Stenberg, Johan A.
- Abstract
The global decline in pollinators has partly been blamed on pesticides, leading some to propose pesticide-free farming as an option to improve pollination. However, herbivores are likely to be more prevalent in pesticide-free environments, requiring knowledge of their effects on pollinators, and alternative crop protection strategies to mitigate any potential pollination reduction. Strawberry leaf beetles (SLB) Galerucella spp. are important strawberry pests in Northern Europe and Russia. Given that SLB attack both leaf and flower tissue, we hypothesized pollinators would discriminate against SLB-damaged strawberry plants (Fragaria vesca, cultivar 'Rügen'), leading to lower pollination success and yield. In addition we screened the most common commercial cultivar 'Rugen' and wild Swedish F. vesca genotypes for SLB resistance to assess the potential for inverse breeding to restore high SLB resistance in cultivated strawberry. Behavioral observations in a controlled experiment revealed that the local pollinator fauna avoided strawberry flowers with SLB-damaged petals. Low pollination, in turn, resulted in smaller more deformed fruits. Furthermore, SLB-damaged flowers produced smaller fruits even when they were hand pollinated, showing herbivore damage also had direct effects on yield, independent of indirect effects on pollination. We found variable resistance in wild woodland strawberry to SLB and more resistant plant genotypes than the cultivar 'Rugen' were identified. Efficient integrated pest management strategies should be employed to mitigate both direct and indirect effects of herbivory for cultivated strawberry, including high intrinsic plant resistance.
- Published
- 2017
- Full Text
- View/download PDF
50. Methods to identify the prey of invertebrate predators in terrestrial field studies
- Author
-
Birkhofer, Klaus, Bylund, Helena, Dalin, Peter, Ferlian, Olga, Gagic, Vesna, Hambäck, Peter A., Klapwijk, Maartje, Mestre, Laia, Roubinet, Eve, Schroeder, Martin, Stenberg, Johan A., Porcel, Mario, Björkman, Christer, Jonsson, Mattias, Birkhofer, Klaus, Bylund, Helena, Dalin, Peter, Ferlian, Olga, Gagic, Vesna, Hambäck, Peter A., Klapwijk, Maartje, Mestre, Laia, Roubinet, Eve, Schroeder, Martin, Stenberg, Johan A., Porcel, Mario, Björkman, Christer, and Jonsson, Mattias
- Abstract
Predation is an interaction during which an organism kills and feeds on another organism. Past and current interest in studying predation in terrestrial habitats has yielded a number of methods to assess invertebrate predation events in terrestrial ecosystems. We provide a decision tree to select appropriate methods for individual studies. For each method, we then present a short introduction, key examples for applications, advantages and disadvantages, and an outlook to future refinements. Video and, to a lesser extent, live observations are recommended in studies that address behavioral aspects of predator-prey interactions or focus on per capita predation rates. Cage studies are only appropriate for small predator species, but often suffer from a bias via cage effects. The use of prey baits or analyses of prey remains are cheaper than other methods and have the potential to provide per capita predation estimates. These advantages often come at the cost of low taxonomic specificity. Molecular methods provide reliable estimates at a fine level of taxonomic resolution and are free of observer bias for predator species of any size. However, the current PCR-based methods lack the ability to estimate predation rates for individual predators and are more expensive than other methods. Molecular and stable isotope analyses are best suited to address systems that include a range of predator and prey species. Our review of methods strongly suggests that while in many cases individual methods are sufficient to study specific questions, combinations of methods hold a high potential to provide more holistic insights into predation events. This review presents an overview of methods to researchers that are new to the field or to particular aspects of predation ecology and provides recommendations toward the subset of suitable methods to identify the prey of invertebrate predators in terrestrial field research.
- Published
- 2017
- Full Text
- View/download PDF
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