103(2)_str22

ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 103, No. 2 (2016), p. 167–174
DOI 10.13080/z-a.2016.103.022

Efficacy of fungicides in sugar beet crops

Dovilė AVIŽIENYTĖ, Zita BRAZIENĖ, Kęstutis ROMANECKAS, Antanas MARCINKEVIČIUS

Abstract

Cercospora and ramularia leaf spot are the most damaging fungal diseases of sugar beet in Europe. The aim of the current study was to evaluate the severity of fungal diseases and the efficacy of various fungicides and their doses in sugar beet crops in Lithuania. A short-term field experiment was carried out in 2012 and 2013 at Rumokai Experimental Station, Lithuanian Research Centre for Agriculture and Forestry on a moderately heavy loam Hapli-Epihypogleyic Luvisol (LVg-p-w-ha). Fungicides Impact (a.i. flutriafol), Opus (a.i. epoxiconazole), Artea (a.i. propikonazole + cyproconazole), Folicur (a.i. tebuconazole), Opera N (a.i. pyraclostrobin + epoxiconazole) were applied as a single application at the beginning of the disease occurrence (in August) and as a double application, with one spray at the beginning of the disease occurrence (in August) plus a second spray one month later (in September).

The experimental results showed that the main fungal diseases in the sugar beet crops tested were Cercospora beticola and Ramularia beticola. Erysiphe betae was of minor severity. The application of fungicides significantly decreased the severity of cercospora and ramularia leaf spots by on average 19.8–81.8% and 71.8–91.8%, respectively. The most effective fungicides were Opus (a.i. epoxiconazole) and Impact (a.i. flutriafol). A single or double application of all the investigated fungicides had essentially the same effect. The most effective against powdery mildew was fungicide Opus, treated twice.

Various active ingredients of the fungicides had insignificant effect on sugar beet yield and sucrose content in the roots. A single application of the fungicide Artea 0.5 L ha-1 (a.i. propiconazole + cyproconazole) and a double application Opus 1.0 L ha-1 (a.i. epoxiconazole) and Folicur 1.0 L ha-1 (a.i. tebuconazole) significantly decreased the content of impurities (potassium, sodium, alpha amino nitrogen) in the sugar beet roots compared with the untreated control treatment.

Key words: Beta vulgaris, Cercospora beticola, Erysiphe betae, quality, Ramularia beticola, yield.

Full text: 103_2_str22.pdf