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Kremer P.,Johannes Gutenberg University Mainz | Schluter J.,Johannes Gutenberg University Mainz | Racca P.,Central Institution for Decision Support Systems in Crop Protection ZEPP | Fuchs H.-J.,Johannes Gutenberg University Mainz | Lang C.,Association of Sugar Beet Farmers in Hesse and Rhineland Palatinate
Climatic Change | Year: 2016

In this study the possible impact of climate change on the occurrence of the Cercospora leaf spot disease (CLS) in sugar beet, triggered by the fungus Cercospora beticola sacc., and its regional differentiation in Southwest Germany was analyzed by means of the forecasting model CERCBET1. The model projects the day of the year (DOY) when 1 %, 50 % and 100 % of the fields in the region are potentially infested by Cercospora Leaf Spot disease (CLS1, CLS50 and CLS100). To run the disease model the data of the REgional climate MOdel REMO were used. The possible impact of climate change on the occurrence was studied comparing three time windows: baseline period ‘B′ (1971–2000), medium-term period ‘K‘ (2021–2050), long-term period ‘L‘ (2071–2100). In addition the ontogenesis of the young sugar beet plants was simulated using a leaf-growth model. The results of CERCBET1 and the leaf-growth model were compared to draw conclusions whether CLS potentially would occur in a different leaf stage. The dates of completion of the 20- and 40-leaf stage (B20 and B40) therefore were examined. The simulation results indicate an earlier CLS occurrence as well as an accelerated leaf growth due to the projected climate change. The disease might occur in earlier growth stages of the sugar beet plants. A possible consequence of the earlier CLS occurrence could be an increasing number of necessary fungicide applications also regarding the prolonged growing season. For period L, especially, projections are difficult to make due to the uncertainties of the archived breeding progress, particularly regarding the breeding for resistance, the development of fungicides and the future socio-economic development. © 2016 Springer Science+Business Media Dordrecht

Racca P.,Central Institution for Decision Support Systems in Crop Protection ZEPP | Kakau J.,Osnabruck University of Applied Sciences | Kleinhenz B.,Central Institution for Decision Support Systems in Crop Protection ZEPP | Kuhn C.,Central Institution for Decision Support Systems in Crop Protection ZEPP
Journal of Plant Diseases and Protection | Year: 2015

There is a general agreement that climate change, in the medium and long term perspective, may affect agricultural crops. As part of the KLIFF project (‘Klimafolgenforschung in Niedersachsen’, consequences of climatic change in Lower Saxony), the impact of climatic changes on the main crops grown in Lower Saxony (Germany) were analyzed with regard to the potential risks of plant diseases. However, climate does not only affect pathogens and diseases directly, but also the phenological development of the crop plants. In the following paper, the consequences of an increase in temperature in the medium (2020–2050) and long (2070– 2100) term perspective on the appearance of the main phenological stages of wheat, sugar beet and winter oilseed rape were analyzed. In this study, three simulation models were involved that predict the appearance of phenological stages using the date of sowing of the crop and the forecasted temperatures from the climate model REMO-UBA (high resolution regional climate model data) as input data. The results of the simulations for the 3 crops show that an earlier appearance of the phenological stages in both the medium and long term simulation is to be expected. Model calculations indicate a particular shift to an earlier mean appearance of phenological stages of 0.14, 0.13 and 0.44 days year–1 (mean trend of the regression analysis for the period 1970–2100) for winter wheat, sugar beet and winter oilseed rape, respectively. Such shifts may have significant consequences for the coincidence of susceptible stages of the crop and infective stages of pathogens and may thus cause decreases, increases or balance shifts in the relative importance of individual pathogens in the future, besides the direct climate change effects on diseases. A comparison of the results of this study with available literature data shows, for example, negative consequences for wheat due to the increased risk of infection by leaf rust, tan spot and septoria leaf spot while the risk of infection of powdery mildew remains unchanged. Cercospora leaf spot on sugar beet may appear at an earlier stage of development of the plant, while the risk of Sclerotinia infection for winter oilseed rape is reduced. The advance in phenological stages of crops addressed in this study could have a positive effect on crop yield; however, this effect can be reduced due to the increased risk of diseases, particularly for wheat and sugar beet. © Eugen Ulmer KG, Stuttgart.

Richerzhagen D.,Central Institution for Decision Support Systems in Crop Protection ZEPP | Richerzhagen D.,Leibniz University of Hanover | Racca P.,Central Institution for Decision Support Systems in Crop Protection ZEPP | Zeuner T.,Central Institution for Decision Support Systems in Crop Protection ZEPP | And 4 more authors.
Journal of Plant Diseases and Protection | Year: 2011

The effect of climate change on the temporal and regional occurrence of Cercospora leaf spot (CLS) of sugar beet in Lower Saxony is analysed using the forecasting model CERCBET1. Based on the hourly weather parameters temperature and relative humidity, this model predicts three events: the time when 1%, 50% and 100% of the fields in a region are infested (T1, T50 and T100). Input data are the results of the regional climate model REMO. The effects of climate change are studied in three time windows: a baseline period B (1971-2000), a medium-term period M (2021-2050) and a long-term period L (2071-2100). A comparison of the time windows B and M shows that T1 has an earlier occurrence by 5.2 days, T50 by 6.7 days and T100 by 10.6 days. In period L, T1 is reached 22.9 days earlier than in period B; the occurrence of T50 and T100 is 25.2 and 32.7 days earlier. For a regional risk analysis, Lower Saxony is subdivided into four interpolation areas. In all three time windows, in every season the epidemic starts in the west and ends in the north, while the east and the south are consistently in the middle of the timeline. One consequence of the earlier occurrence could be an increase of the frequency of fungicide application but from today's perspective the consequences are hardly predictable due to the lack of knowledge about multiple interactions between host and pathogen and the social-economic developments in the future. © Eugen Ulmer KG, Stuttgart.

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