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A field trial was conducted to observe the effects of different irrigation strategies on the yield and the water use, oil content and marginal return of sunflower which was irrigated by means of a drip system during 2010 and 2011 under Çukurova condition of Turkey. The irrigation strategies include three irrigation intervals (A1: 25 mm; A2: 50 mm; A3: 75 mm of cumulative pan evaporation) and six water levels (WL) based upon the percentages of cumulative pan evaporation (WL1= 0.50, WL2= 0.75, WL3= 1.00 and WL4= 1.25). In addition, WL5= PRD50 and WL6= PRD75 treatments were evaluated. They obtained water from alternative laterals 50% and 75% of the WL3 treatment. Additionally, a nonirrigated treatment (NI) was included as control plot in the experiment. In each of the experimental years, the largest and the smallest average yields were acquired from the A2WL4 and NI treatments, respectively. The oil content and fatty acid composition were significantly affected by irrigation strategies. The oil content increased with the increasing amount of irrigation. Among all irrigation intervals, PRD-50 (WL5) treatment provided the largest water use efficiency (WUE) and irrigation water use efficiency (IWUE) values in both growing seasons. In order to attain higher yields and a generated the marginal return, A2WL4 irrigation regime is suggested for sunflower production in the Mediterranean region. A2WL3 water strategy is proposed for an acceptable marginal return in case of water shortage.

The objectives of the present study were to evaluate the effect of drainage water at different growth stages of quinoa (cv. Titicaca) in the Çukurova region of Turkey in 2014 and 2015 on yield, yield components, water use efficiency and salt accumulation in the plant root zone. The line-source sprinkler lateral was used in order to create gradually varying deficit irrigation treatments (I1 through I5). Drainage water was applied to replenish soil water deficit in the 60 cm depth to the field capacity during four growth stages of quinoa (early vegetation, late vegetation, flowering and grain filling) in treatment plots adjacent to sprinkler lateral (I1). Total amount of drainage water applied to treatment (I1) was 344 and 400 mm; and seasonal water use (ET) was 514, and 459 mm, respectively, for two years. Irrigation levels (I1-I4) influenced significantly quinoa yields and yield components. Maximum yield was obtained from the I1 treatment as 4510-4880 kg ha-1; and the lowest yield was obtained from the rainfed treatment (I5) as 1880 and 1430 kg ha-1, respectively. Significant linear relationships were found between seed yield and ET. The yield response factor (ky) was 1.17 in 2014 and 1.06 in 2015. Soil salinity decreased with increasing depth in all treatments. In conclusion, full irrigation using drainage water (1.6 dS m-1) is recommended for sprinkler irrigated quinoa in order to obtain higher yield in the Çukurova region.

This study examines the effects of different irrigation regimes on yield, yield components, oil yield and quality and water use of sunflower (Oleko variety) irrigated with a drip system under field conditions in 2010 and 2011 growing seasons at the Alata Horticultural Research Institute, Tarsus Soil and Water Resources area in the Mediterranean region of Turkey. Irrigation regimes consisted of three irrigation intervals (A1:= 25 mm; A2:= 50 mm; A3: = 75 mm of cumulative pan evaporation) and six irrigation levels (I1=0.50, I2=0.75, I3=1.00 and I4=1.25). In addition, I5=PRD75 and I6=PRD50 treatments were considered. They received 75 and 50% of the full irrigation (I3) treatment from alternative laterals, respectively. Also, rainfed treatment is a control plot in the experiment. Maximum and minimum yields were obtained from the A2I4 and rainfed treatments, respectively in all experimental years. As the irrigation level value decreased the total yields in each irrigation interval also decreased. Seasonal irrigation amounts in the treatments varied from 199 mm to 563 mm in the experimental years. Seasonal evapotranspiration values in the treatments varied from 243 mm to 611 mm in the experimental years. Both irrigation amounts and irrigation frequencies had significantly effects on oil content of sunflower. The saturated (palmitic and stearic acid) and unsaturated (oleic and linoleic acid) fatty acid contents were significantly affected by water stress. In conclusion, A2I4 irrigation regime is recommended for sunflower production in the Mediterranean region in order to attain higher yields with improved quality. In case of water shortage, A2I13 irrigation regime is recommended to increase sunflower yield and quality.