Authors: IRENA BRAZAUSKIENE, EGLE PETRAITIENE, GINTARAS BRAZAUSKAS, ANTANAS RONIS
Abstract: The productivity of winter oilseed rape cultivars is limited by various pests and diseases. The aim of this study was to determine the differences in the susceptibility of Lithuanian-grown winter rape cultivars to main fungal diseases, their yield performance, and their response to the fungicide application. A 2-factorial field experiment was carried out at the Institute of Agriculture of the Lithuanian Research Centre for Agriculture and Forestry over 3 growing seasons (2007/08, 2008/09, and 2009/10). The influence of fungicide application and cultivar (15 cultivars during the first and second seasons, and 6 cultivars during the third season) on the incidence and severity of phoma stem canker, alternaria black spot, and sclerotinia stem rot, as well as on the seed yield and thousand-seed weight, was evaluated. Experimental findings indicated that the incidence and severity of fungal diseases varied considerably among the growing seasons. The incidence of basal phoma stem canker was significantly influenced by the cultivar during all 3 growing seasons; however, significant effect of the cultivar on the mean severity of basal canker was obtained only in 2009. Fungicide spray applications significantly decreased the incidence and severity of fungal diseases and significantly increased the seed yield of winter rape. Significant and positive yield response to the fungicide application was obtained for almost all tested cultivars during the first 2 seasons. Cultivars that were higher yielding without treatment (Insider, Sunday, Monalisa, Rally, and Titan) showed lower response to the fungicide application. The use of fungicides demonstrated the highest economic return from the cultivars Lirajet, Casino, Siska, Liprima, and Valesca.
Keywords: Diseases, economic benefit, fungicides, seed yield, winter rape
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