Variety-specific Epidemiology ofCercospora beticolaSacc. and Consequences for Threshold-based Timing of Fungicide Application in Sugar Beet
| Autor: | Christian Kluth, Bernward Märländer, Ulrike Kaiser |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
2. Zero hunger
0106 biological sciences biology Physiology 04 agricultural and veterinary sciences Plant Science Fungi imperfecti 15. Life on land Plant disease resistance Pesticide biology.organism_classification Cercospora beticola 01 natural sciences Fungicide Horticulture Agronomy 040103 agronomy & agriculture Genetics 0401 agriculture forestry and fisheries Leaf spot Sugar beet Biennial plant Agronomy and Crop Science 010606 plant biology & botany |
| Zdroj: | Journal of Phytopathology. 158:296-306 |
| ISSN: | 1439-0434 0931-1785 |
| DOI: | 10.1111/j.1439-0434.2009.01618.x |
| Popis: | In Central Europe, fungicides to control leaf spot disease in sugar beet caused by Cercospora beticola are applied based on thresholds of disease incidence (DI, per cent of infected plants). As variety-specific fungicide application was not analyzed to date, the epidemiology of C. beticola and its effect on white sugar yield (WSY) in varieties with different susceptibility were investigated at seven sites in Germany and Austria in 2004 and 2005. All varieties reached the summary thresholds 5 ⁄ 15 ⁄ 45% DI in all environments. Fitting a logistic growth curve to DI revealed significant differences among varieties. At high disease pressure, susceptible varieties reached a considerably higher disease severity (DS, per cent of infected leaf area) at harvest and a larger area under disease progress curve (AUDPC) than resistant varieties. Fitting a logistic growth curve to DS showed an increasing differentiation among varieties with time. The growth rate estimated based on the logistic growth curve was the only variable that performed equally well in differentiating varieties under low and high disease pressure. With increasing disease pressure, varieties differed considerably in WSY, but differences between susceptible and resistant varieties were significant only in some environments. The disease-loss relation between AUDPC and relative WSY was varietyspecific. Resistant varieties had an approximately identical WSY with and without infection and compensated for negative infection effects even at higher AUDPC. Therefore, at high disease pressure, resistant varieties had a higher relative yield compared to susceptible ones. However, our results indicate that there is no need to develop variety-specific thresholds, but resistant varieties reach the established thresholds later than susceptible ones. Consequently, the time of fungicide application can be delayed in resistant varieties. This will help to reduce the use of fungicides to the bare essentials as requested for the integrated crop protection management. |
| Databáze: | OpenAIRE |
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