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Forecasting systems for controlling downy mildew (peronospora destruction) in onion

Main subject area: Forecasting, mildew, onion

Short project description

Onion production is threatened by epidemics of downy mildew (Peronospora destructor). To control the disease, fungicides are sprayed repeatedly (8-10 times) in a season. However, this excessive use of a fungicide is unsustainable and counterproductive to the green agenda. There is thus the need to reduce the use of fungicides. One way of regulating the use of a fungicide is via disease forecasting systems/models. These forecasting models predict when conditions favorable for infection by a pathogen are present, and thus recommend the application of fungicide. Currently, there are no forecasting models for timing the application of fungicides in onions in Denmark. However, there are existing models (e.g. MILLIONCAST, DOWNYCAST) that have proven useful in other countries. The objective of this project is to evaluate different forecasting models from the literature for timing fungicides and biological control agents for controlling downy mildew in onions.

The project is part of the InnovateIPM project (https://agro.au.dk/forskning/projekter/innovate-ipm)

Department and supervisor

Isaac Kwesi Abuley

Tenure Track assistant professor

Project start

Ideally, from Ju 2024, but a different start date can be arranged

Physical location of project and students work

Forsøgsvej 1, 4200, Slagelse

Extent and type of project

ECTS: 45 or 60 ECTS


ARAÚJO, E. R., ALVES, D. P. & KNOTH, J. R. 2017. Weather-based decision support reduces the fungicide spraying to control onion downy mildew. Crop Protection, 92, 89-92.

ARAÚJO, E. R., RESENDE, R. S., ALVES, D. P. & HIGASHIKAWA, F. S. 2019. Integrating cultivar resistance and disease warning system to control downy mildew of onion. Australasian Plant Disease Notes, 15, 1.

GILLES, T., PHELPS, K., CLARKSON, J. P. & KENNEDY, R. 2004. Development of MILIONCAST, an Improved Model for Predicting Downy Mildew Sporulation on Onions. Plant Disease, 88, 695-702.

JESPERSON, G. D. & SUTTON, J. C. 1987. Evaluation of a forecaster for downy mildew of onion (Allium cepa L.). Crop Protection, 6, 95-103.


VAN DER HEYDEN, H., BILODEAU, G. J., CARISSE, O. & CHARRON, J.-B. 2020. Monitoring of Peronospora destructor Primary and Secondary Inoculum by Real-Time qPCR. Plant Disease, 104, 3183-3191.