Effectiveness of chemical control products from fungal foliar diseases in sugar beets

Abstract

The most effective control products from Cercospora leaf spot and Ramularia leaf spot was fungicide, which contained active ingredient - epoxiconazole (85.4-88.2). Spraying epoxiconazole twice a growing season was 1.4 times more effective than spraying once. Lowest biological effectiveness from these diseases was using fungicide, which contained active ingredient - tebuconazole (48.6- 66.2). All tested chemical control products, from fungal leaf diseases, increased root yield (1.9-15.1 %). The strongest and significant effect of sugar beet yield was spraying fungicide, which contained active ingredient epoxiconazole (95-97 t ha'1). Lowest yield - was spraying fungicide, which contained active ingredient tebuconazole (83-87 t ha1). Sugar beet (Beta vulgaris L. ssp. vulgaris var. altissima Doell) is an important crop in Lithuania. It is the main raw material for sugar production and is used in food, chemical and other industries. Moreover, it is valuable forage for livestock. In sugar beet production, diseases are a major concern because they can result in considerable yield losses, as well as reduce sugar content, extraction and storage life of roots in clamps. The most important the most widespread and most damaging foliar fungal diseases of sugar beets in Lithuania are Cercospora leaf spot (pathogen - Cercospora beticola Sacc.) and Ramularia leaf spot (Ramularia beticola Fautrey & F. Lamb.). The use of effective disease control agents can stave off the damaging effects of pathogens on plants and prevent quality deterioration and reduction of sugar content. The current study is aimed to investigate sugar beet fungal diseases, their incidence and severity and to identify effective control products. The research was made in the Rumokai Experimental Station of the Lithuanian Research Centre for Agriculture and Forestry in 2012. There were investigated most harmful sugar beets fungal foliar leaf diseases (Cercospora leaf spot, Ramularia leaf spot) and identified effective chemical control products. Cercospora leaf spot and Ramularia leaf spot in sugar beet crop started spreading in the end of July. One month after the first fungicide spray, Cercospora leaf spot severity in fungicide sprayed plots were 2-7.2 times significantly lower than in untreated plots, Ramularia leaf spot - 1.3-3 times. Before harvesting sugar beets, Cercospora leaf spot severity in fungicide sprayed plots was 1.9-8.5 times significantly lower than in the untreated plots, Ramularia leaf spot - 2.5-7 times.