Current potato varieties are too susceptible to late blight to be grown without chemical control under North-East European conditions

Abstract

The main aim of this research was to evaluate foliar resistance of the potato varieties of Dutch breeding company Agrico to find those most resistant to late blight in order to diminish the number of fungicide sprays required while obtaining a high yield in North-East European conditions. In the trial at the Einola Farm in 2010 and 2011, 10 potato varieties and 2 breeding lines were included. The disease scores of different varieties varied from 2.1 to 7.6 points. Nine of the varieties grown were susceptible and two varieties very susceptible to late blight. The most resistant variety was Toluca (foliar blight estimated mean value 5.9), which is immune to foliar blight in its land of origin. On the basis of two years data, we can conclude that most of the tested varieties are too susceptible to late blight to be grown without chemical control against this pathogen in North-East European conditions. © 2013 Copyright Taylor and Francis Group, LLC.