Perfecting potato disease predictions

Teagasc highlights the impacts of its latest research in "Research impact highlights in 2020". Research into potato blight undertaken by Steven Kildea and Mladen Čučak qualified as one of the highlights. Teagasc is engaged in an extensive range of research of national and international collaboration

Following a critical evaluation of the late blight risk prediction model used to forecast potato late blight in Ireland, Met Éireann has incorporated suggested revisions into its late blight forecasting model. The project was undertaken as part of a collaborative effort between Teagasc, Maynooth University and Met Éireann.

As part of the Teagasc potato breeding programme, from 2006-2016 outbreaks of the late blight disease were recorded together with weather conditions preceding each outbreak, making it possible to improve disease prediction. This included reducing the threshold of relative humidity and the definition of leaf wetness to include both rainfall and/or relative humidity >90%. Using these changes, it was hypothesised that significant reductions in fungicide usage could be achieved.

Field trials undertaken during 2017-2019 validated the improved predictably of these revisions, with significantly lower levels of disease observed in the revised model compared to the model operated by Met Éireann. This increased predictability ensured fungicide applications could be better targeted, allowing for reduced fungicide usage across the season. Following these findings, from 2021 onwards Met Éireann has issued late blight forecasts based on this revised model.

Correspondence: stephen.kildea@teagasc.ie
Other contributors: Rowan Fealy (Maynooth University) and Keith Lambkin (Met Éireann).
Funding: Department of Agriculture, Food and the Marine Research Stimulus Fund (EPIC project).

Find out more here about the 2020 Research Impact Highlights from Teagasc