Fungal disease resistance of perspective sugar beet varieties and their yield potential

Abstract

The research was conducted on 11 sugar beet varieties, grown at the Rumokai Experimental Station of the Lithuanian Research Center for Agriculture and Forestry, in 2016 and 2017. The experiments were carried out on two backgrounds: the crops were not sprayed and sprayed with fungicide epoxiconazole 125 g l^–1. During the study years, rust (causative agent Uromyces beticola), powdery mildew (causative agent Erysiphe betae Vaňha Weltzien) and leaf spot disease (causative agent Cercospora beticola Sacc.) were the most prevalent in sugar beet. Rust, the intensity of which was 9.66–61.79%, caused most damage to sugar beet. The intensity of powdery mildew was 12.71–55.98% and that of leaf spot disease was 7.47–54.23%. Of the investigated varieties of sugar beet, the most sensitive to leaf spot disease were ‘Merens’, ‘Balear’, ‘Davinci’, ‘Kashmir’ and ‘Pottok’, the most resistant were ‘Berton’, ‘Selma KWS’ and ‘Wellington’. ‘Merens’ and ‘Texel’ were the most sensitive to rust. This disease was least damaging to the ‘Minta’, ‘Berton’ and ‘Strauss’ varieties. Powdery mildew was most harmful to leaves of the ‘Merens’, ‘Balear’ and ‘Minta’ varieties of sugar beet. The most resistant to powdery mildew was ‘Texel’. According to the average two-year data, the most productive was the ‘Pottok’ variety, whose root yield was 90.46– 93.85 t ha^–1. The ‘Straus’ variety had the highest sugar content. Epoxiconazole increased the sugar beet yield from 0.44 to 6.53 t ha^–1 in 2016 and from 0.07 to 11.63 t ha^–1 in 2017.