Effect of an Aggressive New Race Broomrape (Orobanche Cumana L.) on Agronomical and Technological Traits of the Sunflower in Mediterranean Environments

Sunflower ( Helianthus annuus L.) is the most important edible oil crop in Turkey as 85% of the edible oil consumed is made from it. A major limiting factor in sunflower-producing countries is infestation by the parasitic plant Orobanche cumana . In all regions of Turkey where sunflower is grown, sunflower plants exhibiting various degrees of infestation by this parasite and various invasive groups of this parasite have been observed. The aim of this study was to assess the tolerance of sunflower varieties to the new aggressive parasitic race and to determine its effect on agronomical and technological traits of the sunflower. Our results over a two-year study of agronomically important traits indicate that the hybrids, HA-4 and HA-5, are fully resistant to the parasite under field conditions and had significantly higher seed yield and oil content than the standards. Therefore, new sources of genetic resistance and herbicide-resistant sunflower hybrids are required against highly invasive races for this region.