Strategies to Control Late Blight in Potatoes in Europe

Abstract

In Europe an aggressive genetically diverse population of potato late blight is present which regularly causes problems in all potato growing regions. It is therefore of the utmost importance that blight is managed in an integrated way by combining a range of measures. Hygiene measures can keep the number of primary sources of inoculum low. In a number of European countries campaigns are ongoing to increase the awareness of growers to reduce the risk of early inoculum sources such as dumps, volunteers and infected seed. The use of varieties with stable resistance for foliar and tuber blight is also a part of an integrated control strategy. In intermediate resistant varieties possibilities are investigated to reduce the input of fungicides. Fungicides still have a key role to play in the integrated control of late blight. In order to optimize the use of fungicides it is important to know the effectiveness and type of activity of the active ingredients to control blight. The use of fungicides should be targeted by using information on infection conditions based on weather data, disease pressure and fungicide characteristics. Decision Support Systems (DSS) can be used to integrate and organize all the available information required for decisions to control late blight. INTRODUCTIONLate blight was first introduced into Europe in the 1840s and is now the most serious potato disease. Nowadays an aggressive genetically diverse population with both the A1 and A2 mating type is present which regularly causes problems in all potato growing regions in Europe. In this situation the first outbreaks of late blight are detected earlier in the season and the development of the epidemic during blight conducive weather can be faster compared to the pre-1980s situation in which Europe had an asexual genetically similar population. It is therefore of the utmost importance that potato late blight is managed stringently by combining a range of control measures. In this paper some examples are presented of elements that can be part of an integrated control strategy of potato late blight. Measures are described related to the management of primary infection sources as well as the integration of resistant cultivars in the control strategy. Also the optimal use of a wide range of fungicides is presented and some examples of Decision Support Systems used in Europe are presented.

Reduced efficacy of fluazinam against Phytophthora infestans in the Netherlands

“…The average number of sprays per season varies from 7 to 20 depending on the weather, disease pressure and crop (Schepers et al 2009;Cooke et al 2011). Since its introduction in the Netherlands in 1992, fluazinam has been used in late blight control strategies in ware and starch potatoes.…”

Spatiotemporal analysis of Phytophthora infestans population diversity and disease risk in Great Britain

“…In addition to crop failures and decreased yield, the potato late blight pathogen is responsible for significant economic costs associated with fungicide use and storage losses due to tuber blight. Integrated management of the pathogen relies on a wide range of strategies, including the control of primary inoculum sources, the use of resistant cultivars, and optimizing fungicide usage in response to a demonstrated need via scouting or forecasting (Cooke et al, 2011; Ritchie et al, 2019; Schepers et al, 2009). Populations of the pathogen have changed in recent years, and this has direct implications for the management of the potato late blight disease (Cooke et al, 2012).…”