Partners and International Organizations
(English)
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AT, BE, BG, CH, CY, CZ, DE, DK, ES, FI, FR, GR, HR, HU, IE, IL, IT, LU, NL, NO, PL, PT, RO, RS, SE, SI, SK, TR, UK
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Abstract
(English)
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Current and projected climate change in temperate regions of Europe will lead to higher and more extreme temperature distributions and less stable precipitation regimes with increased drought and flooding risks, respectively. In addition to such direct climate change effects on agricultural cropping systems, also pest and disease populations will be largely influenced which will affect plant health and productivity. Species ranges will likely be extended from South to North, generation time will be shortened, and infection periods will shift within seasons, all of which can jeopardise the sustainability of present plant protection strategies. Whereas crop yield is generally expected to benefit from milder temperatures, the impact on pest and disease is rarely investigated in detail. One major reason is the problem of downscaling climate predictions to the temporal and spatial scale of pest and disease life cycles. In the present project, we have approached to close that gap by impact modelling on hourly scale and downscaling on spatial scale by adapting a stochastic weather generator for pest and disease modelling. The impact of climate change and variability was evaluated for two major pest and disease threats to apple, one of the most important commercial and rural crops across Europe. Thereby codling moth, Cydia pomonella, serves as a relevant model for a pest with multiple generations per year that already under present climate requires intensive efforts to control without generating resistance to insecticides. Fire blight, caused by the invasive quarantine bacterium Erwinia amylovora, substantially threatens sustainable apple/pear production across Europe. Although Fire blight infection risk and thus control measures are closely linked to abiotic conditions, particularly during the most epidemiological important flowering period, no significant change in the number of infection days can be detected from the median scenario of temperature, precipitation frequency and intensity changes in Northern Switzerland. Only the station Magadino in Southern Switzerland shows an significant increase in the fire blight infections. Nevertheless, there may be a higher risk of environmental drawback from antibiotic Streptomycin applications for fire blight management under conditions of changing climate. For Codling moth, under conditions of changing climate the risk of a pronounced second generation (45% larval emergence) will increase to 70-100%. Also an increased risk up to 100% of an additional third generation (as measured by adult flight start) will be found in Swiss apple orchards. We identified a significant two-week shift to earlier dates in codling moth phenological events, such as overwintering adult flight start. The magnitude of first generation pupae and all later events will significantly increase under changing climate conditions. Additionally first generation pupae and later events will be prolonged. Codling moth, will have to be controlled in future over multiple generations of high magnitude which means that all current strategies, especially pheromone mating disruption, have to be combined and carefully supplemented by newly available plant protection agents to sustain their success and avoid development of resistances. The outcome of the project enables us to estimate risks of climate change for recent pest and disease management scenarios, and to adapt plant protection strategies to maintain their sustainability. The general results and methodologies of the project may easily be adapted in further pest and disease combinations as well as in other cropping systems.
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