(Manuscript received 2017; accepted for publication 5 February 2018)
Abstract. The aim of the present article was to introduce the new Bulgarian sunflower hybrid Sevar, which since 2015 has been included in the European Catalog of Field and Vegetable Crop Varieties. Sunflower hybrid Sevar was developed at Dobrudzha Agricultural Institute (DAI), General Toshevo. The hybrid is male sterile, two-linear and was obtained by interlinear hybridization. The parental components are line 807А, which possesses cytoplasmic male sterility, and the father line is 509R, a branched fertility restorer line developed through in vitro methods. The two lines demonstrated very good combining ability. Sevar is an early maturing hybrid, with duration of the vegetation period of 107–110 days. Plant height is within the range of 155-160cm, and the head diameter is 26–29cm. The seeds have absolute weight 48–57g and oil content 49–50%. The oil is of linoleic type. The percent of kernel in the seed is 75 – 76%, and the protein in the whole seed is 19–20%. The weight of seeds per plant is 69-80g, and the number of seeds is 1150-1300. The duration of flowering is 10–12 days. The maximum seed yield obtained in the experimental fields of DAI is 4300 kg/ha, and in the neighboring Romania – 6406 kg/ha. In the breeding fields of DAI, the hybrid was tested three years according to a scheme approved for this crop. During the testing period, Sevar exceeded the mean standard by seed yield with 2.7–11.8%. By oil yield, the exceeding during the three years was within 3.5 – 19.1%. The highest yield was observed in 2010 – 4002 kg/ha seed yield and 1985 kg/ha oil yield. The oil content of this hybrid reached 49.6% and was higher than the standards San Luka and Brio. Sevar is resistant to the economically important diseases downy mildew (up to race 731) and the parasite Orobanche (up to race F). Hybrid Sevar was registered in Romania with certificate No. 4934/09.06.2015 and was included in the European Catalog of Field and Vegetable Crop Varieties.