FRESENIUS ENVIRONMENTAL BULLETIN, cilt.24, ss.4095-4101, 2015 (SCI-Expanded)
Sunflower is an indispensable crop for rain-fed conditions in Turkey, where productivity of sunflower has been dependant on rainfall during growing season. This research was carried out to investigate the potential of row direction, plant arrangement and seed priming in increasing yield and oil ratio of sunflower under rain-fed conditions in Turkey. The experiment was established during the summer seasons of 2010 and 2011 using four row directions (North-East, South-West, Northeast-Southwest and Northwest-Southeast), three plant arrangements (70 x 30, 60 x 35 and 50 x 42 cm) and seed priming treatments (control, hydropriming and KNO3) with the cultivar Sanbro MR. In the study, days to flowering, plant height, head diameter, thousand seed weight, seed yield, oil ratio and photosynthetic parameters were investigated. The results showed that seed yield, yield components, oil ratio, and photosynthetic parameters were higher in 2011 due to high precipitation and low temperature. Seed yield obtained from all row directions ranged from 2106-2367 kg ha(-1) in 2010 and 41154263 kg ha(-1) in 2011, with no significant differences between row directions. None of the row directions tested enhanced seed yield or oil content. Hydropriming and the plant arrangement of 60 x 35 cm were found to be effective for increasing seed yield. The rate of photosynthesis also was higher in 2011, along with the investigated agronomic characteristics. Seed priming increased the rate of photosynthesis and the increased photosynthetic activity was evaluated as an indicator of improved seed yield. It was concluded that a plant arrangement of 60 x 35 cm and hydropriming should be the preferred techniques for increasing seed yield of sunflower regardless of row direction.