Search

Çalışma, damla sulama sistemlerinin performans ve tıkanıklık düzeylerini belirlenmesi amacıyla 2018 yılında Kuzey Kıbrıs Türk Cumhuriyeti (KKTC) ilçeleri olan Güzelyurt, Lefkoşa 3, Girne, İskele ve Gazimağusa bölgelerinde toplam 17 üreticiye ait tarımsal işletmelerde yürütülmüştür. Yapılan çalışma geniş kapsamlı olup ada genelinde damla sulama sistemini kullanan üreticiler örnek alan olarak belirlenmiştir. Çalışmada bölgeler; Güzelyurt “GY”, Lefkoşa “L”, Gazimağusa “GM”, Girne “G” ve İskele “İ” simgeleri ile gösterilmiş ve üretici ismi (1, 2, 3 ve 4) rakamla ifade edilerek konular oluşturulmuştur. Çalışma bölgesinde ki üreticilere ait damlatıcı yapım farklılık katsayısı değerleri çok düşük ve istenmeyen sınır değerlerinin altında çıkmıştır. Çalışmada damlatıcı türdeşlik değeri en düşük %60.2 ile GM4 üreticisinde, en yüksek değer %89.1 ile G1 üreticisinde elde edilirken, en düşük istatistiksel damlatıcı üniformite değeri %49.5 ile GM1 ve en yüksek %89.1 ile GY1 üreticindeki damla sisteminden elde edilmiştir. Çalışmada bölgelerindeki üreticiler sulama kaynağı olarak Güzelyurt akiferini kullanmaktadır. Güzelyurt akiferi bölgesine düşen yağış miktarının düşük olması, yöredeki çiftçilerin aşırı akiferden su çekmesi ve denizden akifere tuz taşınımlarının artması akifer suyunun tuzlanmasına neden olmaktadır. Bölgede damla yönteminde akiferden suyun kalitesinin düşük ve denetim birimindeki arıtma fitrelerinin arıtmada yetersiz olmasından dolayı sistemini performansını etkilediği ve tıkanmalara neden olduğu belirlenmiştir.

This study evaluated the yield and water productiivty response of quinoa to regulated deficit irrigation (RDI), partial root-zone drying (PRD) and conventional deficit irrigation (DI) and full irrigation (FI) using surface (SD) and subsurface drip (SSD) systems in 2016 and 2017 in the eastern Mediterranean region of Turkey. The treatments consisted of RDI, PRD50, DI50, DI75 and FI. A rainfed treatment (RF) was also included in the study. The experimental design was split plots with four replications. DI75 and DI50 received 75 and 50% of FI, respectively. PRD50 received 50% of FI, but from alternative laterals. RDI received 50% of FI during vegetative stage until flowering, and then received 100% of water requirement. The results showed that quinoa under SD used slightly more water than SSD due to reduced surface evaporation. RDI resulted in water saving of 23 and 21% for SD and SSD, respectively, compared to FI; and RDI produced statistically similar grain yields to FI. DI75 treatment resulted in water savings of 16% for both drip methods in the first year and 10 and 25% for SD and SSD systems, respectively, in the second year. PRD50 produced greater yield than DI50 eventhough they received the same amount of irrigation water. RF and PRD50 treatments resulted in significantly greater water productivity (WP) values than other treatments. There was no significant difference between SD and SSD regarding the grain and dry matter yields and WP values. Thus, RDI and DI75 appear to be good alternatives to FI for sustainable quinoa production in the Mediterranean region.

The effects of various irrigation strategies applied with drip system and different planting dates on yield, components and water use efficiency of chickpea (Cicer arietinum L.; var. Inci), were evaluated during 2010 and 2011 under Mediterranean conditions. The treatments included full irrigation (FI), mild deficit irrigation (DI-75), severe deficit irrigation (DI-25), partial root-zone drying (PRD-50), and non-irrigated (DRY) for winter and spring planting times. DI-75, PRD-50, and DI-25 received irrigation water 75, 50, and 25% of full irrigation, respectively. Both irrigation regimes and sowing dates had significantly different effect on grain yields. Interaction of irrigation and sowing dates was also significant in 2011. Water stress reduced significantly yield of spring-planted chickpea as compared to winter-planted chickpea. The greatest yields of 4.40 and 2.85 t ha-1 were recorded, respectively, for winter- and spring-planted chickpeas under FI. The greatest water use efficiency was 0.70 kg m-3 for winter-planted and 1.03 kg m-3 for spring-planted chickpeas in DRY treatment. WUE increased with decreasing irrigation amounts for both planting times. Winter planting performed better than spring planting for the yield and yield attributes. However, in dry years, deficit irrigations DI-75 and PRD-50 can be practiced to obtain higher yields with winter sowing.

A 2-year field experiment was conducted with the objectives to evaluate the physiological and yield response of quinoa cv Titicaca to various deficit irrigation strategies applied with surface drip (SD) and subsurface drip systems (SSD) under the Mediterranean climatic conditions in 2016 and 2017. The treatments consisted of regulated deficit irrigation (RDI), partial root-zone drying (PRD50), conventional deficit irrigations (DI50, DI75) and full irrigation (FI) under SD and SSD. A rainfed treatment was also included. The experimental design was split plots with four replications. DI(75)and DI(50)received 75 and 50% of FI, respectively. PRD(50)plots received 50% of FI, but from alternative laterals in each application. RDI received 50% of FI during vegetative stage until flowering, then received 100% of water requirement. The results indicated that RDI resulted in water saving of 23 and 21% for surface drip (SD) and SSD systems, respectively, and RDI produced statistically similar yield to FI treatment in both experimental years. DI(75)treatment resulted in water savings of 16% for both drip methods in the first year and 10 and 25% for SD and SSD systems, respectively, in the second year. Thus, RDI and DI(75)treatments appear to be good alternative to FI for sustainable quinoa production in the Mediterranean environmental conditions. Greater leaf water potential (LWP) and smaller crop water stress index (CWSI) values were measured in FI plots under both drip systems than deficit irrigation treatment plots. Significant second-order polynomial relations were determined between CWSI and LWP for the drip systems. Leaf area index (LAI), LWP decreased and CWSI increased as the drought increased. CWSI correlated significantly (P < 0.01) and negatively with grain yield, dry matter yield, LAI, and mean soil water content indicating that grain yield of quinoa declined with increasing CWSI values. All these relations are best described by significant second-order polynomial equations. The results revealed that quinoa should be irrigated at LWP values between - 1.35 and - 1.60 MPa, and average CWSI value of approximately 0.35 for high yields.

Irrigation water scheduling is crucial to make the most efficient use of ever-decreasing water. As excessive irrigation decreases yield, while imprecise application also causes various environmental issues. Therefore, efficient management of irrigation frequency and irrigation level is necessary to sustain productivity under limited water conditions. The objective of the current study is to assess the water productivity at various irrigation regimes during peanut crop growing seasons (2014 and 2015) in Eastern Mediterranean, Turkey. The field experiments were conducted with treatments consisting of three irrigation frequencies (IF) (IF1: 25 mm; IF2: 50 mm; and IF3: 75 mm of cumulative pan evaporation (CPE)), and four irrigation water levels (WL1 = 0.50, WL2 = 0.75, WL3 = 1.0, and WL4 = 1.25). WL1, WL2, WL3, and WL4treatments received 50, 75, 100, and 125 of cumulative pan evaporation. The CSM-CROPGRO-Peanut model was calibrated with experimental data in 2014 and evaluated with second-year experimental data (2015). The model simulated seed yield and final biomass (dry matter) reasonably well with low normalized root mean square error (RMSEn) in various irrigation intervals. The model simulated reasonably well for days to anthesis (RMSE = 2.53,d-stat = 0.96, andr2 = 0.90), days to physiological maturity (RMSE = 2.55), seed yield (RMSE = 1504), and tops biomass dry weight at maturity (RMSE = 3716). Simulation results indicated good agreement between measured and simulated soil water content (SWC) with low RMSEnvalues (4.0 to 16.8% in 2014 and 4.3 to 18.2% in 2015). Further results showed that IF2I125irrigation regime produced the highest seed yield. Generally, model evaluation performed reasonably well for all studied parameters with both years’ experimental data. Results also showed that the crop model would be a precision agriculture tool for the extrapolation of the allocation of irrigation water resources and decision management under current and future climate.

This study aimed at examining the effects of different irrigation regimes (amount and frequency)on yield, water use, water productivity (WP), irrigation water productivity (IWP)and disease rate of drip irrigated peanut (Arachis hypogaea)during the 2014 and 2015 seasons in the Eastern Mediterranean region of Turkey. The treatments consisted of combinations of 3 irrigation frequencies (IF)(IF1: 25 mm; IF2: 50 mm; IF3: 75 mm of cumulative pan evaporation (CPE)), and 7 irrigation water levels (WL1 = 0.50, WL2 = 0.75, WL3 = 1.00 and WL4 = 1.25). WL1, WL2, WL3 and WL4 treatments received 50, 75, 100 and 125 of CPE. In addition, partial root drying (PRD)treatments WL5 = PRD50, WL6 = PRD75 and WL7 = PRD100 treatments were considered. They received 50, 75 and 100% of WL3 treatment from alternate laterals, respectively These 21 treatment combinations were arranged and analysed in a split-plot design with 4 replications. The main plots and subplots were established to irrigation frequencies (IF1, IF2 and IF3)and levels (WL1, WL2, WL3, WL4, WL5, WL6 and WL7). Both IF and WL were observed to have significantly influenced peanut yields at 1% level. In each of the experimental years, the largest and the smallest average peanut yields were acquired from the IF2WL4 and IF3WL1 treatments, respectively. Results indicated that peanut crops under PRD produced higher than those under deficit irrigation upon usage of the same volume of water amount. Significant linear relationships between irrigation – yield and evapotranspiration – yield were obtained during different irrigation frequencies in each season. The yield response factor (ky)was 0.58–0.65 in IF1, 0.65–0.70 in IF2 and 0.90–0.91 in IF3 plots in both years. Water stress raised the disease emergence in peanut markedly in the experimental years. The WP and IWP of PRD peanut were significantly greater than full irrigation and deficit irrigation (DI)treatments in both growing seasons, which demonstrated that limiting water did not reduce WP values. We conclude that DI treatments resulted in importantly lower WP (p ? 0.05)than PRD treatments in both years in spite of applying the same volume of water. © 2019 Elsevier B.V. TSKAD/14A13/P02/06 This research was funded and supported by General Directorate of Agricultural Research and Policies (TAGEM) under project number TSKAD/14A13/P02/06. We thank editors for their enthusiasm and dedication, the anonymous reviewers for their critical and constructive comments which helped greatly for the revised version.

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 non-irrigated 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 A2 WL4 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, A2 WL4 irrigation regime is suggested for sunflower production in the Mediterranean region. A2 WL3 water strategy is proposed for an acceptable marginal return in case of water shortage. © Ankara Üniversitesi Ziraat Fakültesi. The authors would like to thank the General Directorate of Agricultural Research and Policies (TAGEM) for its financial support to the project of TAGEM-BB-090201C3. We also thank editors for their enthusiasm and dedication, and the reviewers for their critical and valuable comments on the

A study was conducted to analyse the physiological response of red pepper (Capsicum annuum L.) to different irrigation regimes by means of periodical measurements of leaf water potential (LWP) and stomatal resistance (rs) and crop water stress index (CWSI) at midday during 2010 and 2011 seasons in the Mediterranean region of Turkey. The treatments consisted of full irrigation (FI), deficit irrigation (DI-75, DI-50), partial root zone drying (PRD-A, PRD-F, A: alternative, F: fixed). The greatest yield was obtained from the FI treatment followed by DI-75, PRD-A, DI-50 and PRD-F treatments resulted in the smallest yield. The FI irrigation treatment had less stomatal resistance (17.4 s cm-1 in 2010 and 16.4 s cm-1 in 2011) and CWSI (0.25 in 2010 and 0.27 in 2011) in comparison with deficit irrigation treatments. Red pepper performed best at FI with a corresponding leaf water potential of -0.65 to -0.53 MPa for experimental years. There were large differences among treatments in LWP, CWSI and rs, indicating that crop responded differently to different soil water levels. Significant relationship between stomatal resistance, water use and yield were obtained. The results also revealed significant dependency among CWSI, rs and LWP were found. © 2018 Elsevier B.V. TOVAG-109O693 The authors would like to thank the Turkish Scientific and Technical Research Council (TUBITAK) for its financial support to the project of TOVAG-109O693. We thank Dr. Terry Howell, retired Researcher Leader at USDA-ARS, Bushland, Texas, for valuable comments on the manuscript.

The effects of different irrigation regimes on yield and quality and net profit of processing red pepper irrigated with drip and furrow irrigation systems under field conditions in the Mediterranean region of Turkey were evaluated over two years. The treatments for drip consist of full irrigation (DFI), deficit irrigation DDI‐75, D‐PRD‐50, DF‐PRD‐50 and DDI‐50, and for furrow: full irrigation (FFI), fixed alternative furrow (FAF‐50) and PRD furrow (FPRD‐50). FAF‐50 and FPRD‐50 received 50% of water applied to FFI. In FAF‐50 the same furrows were irrigated while FPRD‐50 was irrigated alternately. Irrigation methods and levels had a significant effect on total yield and some quality parameters of red pepper. Drip produced higher red pepper yields than furrow. The highest yield in the drip system was obtained from the DFI treatment followed by DDI‐75, DDI‐50 and DF‐PRD‐50 treatments. Although D‐PRD‐50, DF‐PRD‐50 and DDI‐50 received the same amount of water, D‐PRD‐50 resulted in a higher yield. In furrow treatments, FFI resulted in the highest yield, followed by FPRD‐50 and FAF‐50. Water productivity (WP) decreased with increasing water quantity for both irrigation systems. Fruit weight, size and flesh thickness were higher in the DFI and FFI treatments. Full irrigation treatments (DFI and FFI) generated the highest net income.

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 rainfedtreatments, 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., Çukurova koşullarında damla yöntemiyle sulanan Oleko çeşidi ayçiçeğinde farklı sulama programlarının verim, verim bileşenleri, yağ verimi, yağ kalitesi ve su kullanımı üzerine etkilerini belirlemek amacıyla 2010-2011 yıllarında Alata Bahçe Kültürleri Araştırma Enstitüsü Tarsus Toprak ve Su Kaynakları arazisinde yürütülmüştür. Çalışmada 3 farklı sulama aralığı, yığışımlı buharlaşma değerlerinden (A1:= 25 mm; A2:= 50 mm; A3:= 75 mm olduğunda sulama) oluşurken, 6 farklı sulama düzeyi (I1= 0.50; I2=0.75; I3=1.00; I4=1.25; I5=PRD-75 konusu I3 konusuna uygulanan suyun %75’i alternatif laterallerden, I6=PRD-50 konusunda ise I3 konusuna uygulanan suyun %50’i alternatif laterallerden) uygulanmıştır. Ayrıca, susuz konu kontrol amaçlı incelenmiştir. En yüksek verim A2I4, en düşük verim ise kontrol (susuz) konusundan alınmıştır. Konulara uygulanan toplam sulama suyu miktarları yıllara göre 199-563 mm, bitki su tüketimi değerleri 243-611 mm arasında değişmiştir. Sulama aralığı ve sulama düzeyi ayçiçeğinde yağ %’sini önemli derecede etkilemiştir. Su stresi doymuş (palmitik ve stearik asit) ve doymamış (oleik ve linoleik asit) asit içeriklerini etkilemiştir. Sonuçta; A2I4 sulama programı yörede yüksek ürün almak için önerilebilir. Su kısıntısı söz konusu olduğunda A2I3 konusu ayçiçeği verim ve kalitesini arttırmak için önerilebilir.

This study compares the effects of different irrigation regimes on seed yield and oil yield quality and water productivity of sprinkler and drip irrigated sunflower (Helianthus annus L.) on silty-clay-loam soils in 2006 and 2007 in the Mediterranean region of Turkey. In sprinkler irrigation a line-source system was used in order to create gradually varying irrigation levels. Irrigation regimes consisted of full irrigation (I1) and three deficit irrigation treatments (I2, I3 and I4), and rain-fed treatment (I5). In the drip system, irrigation regimes included full irrigation (FI-100), three deficit irrigation treatments (DI-25, DI-50, DI-75), partial root zone drying (PRD-50) and rain-fed treatment (RF). Irrigations were scheduled at weekly intervals both in sprinkler and drip irrigation, based on soil water depletion within a 0.90m root zone in FI-100 and I1 plots. Irrigation treatments influenced significantly (P

This study was carried out to determine the most suitable irrigation scheduling of fresh market tomato (Fantastic-144) grown on volcanic ash, peat and their mixture (1:1) under Plastic house conditions at Alata Horticultural Research Institute in the Mediterranean Region of Turkey in 1998. The quality and yield response of Fantastic-144 to trickle irrigation was also investigated. Four different irrigation levels (WL1 = 75%, WL2 = 100%, WL3 = 125% and WL4 = 150% of Class A Pan evaporation) and two irrigation frequencies (once and twice daily applications) were evaluated. Highest yield and fruit number were obtained from the ash+peat (1:1) with irrigation once a day at WL4 and ash+peat (1:1) with twice a day watering at WL3 and WL4 irrigation levels. Soluble solids of tomato fruit decreased with increasing available water. The highest WUE value of 67.5 kg m-3 was obtained from WL1 with peat+ash (1:1). WUE decreased in all treatments as the amount of irrigation water increased. © 2006 Asian Network for Scientific Information.

An experiment was conducted to determine the effect of water stress on yield and various physiological parameters including crop water stress index for drip and furrow irrigated processing red pepper in the 2010-2011 growing seasons in the Mediterranean region of Turkey. Drip treatments consisted of full irrigation (DFI), deficit irrigation DDI-75 and DDI-50 which received 75 and 50% of DFI, respectively. D-PRD-50 and DF-PRD-50 alternative and fixed partial root drying, received 50% of DFI. Furrow treatments consisted of full irrigation (FFI), fixed alternative furrow (FAF-50) and PRD furrow (FPRD-50). FAF-50 and FPRD-50 received 50% of water applied to FFI. In FAF-50 the same furrows were irrigated while FPRD-50 was irrigated in alternate furrows. The experimental design was randomized blocks with four replications for drip and furrow treatments. Both irrigation methods and levels had a significant effect on the total yield of red pepper. Drip produced higher red pepper yields than furrow. The highest yield was obtained from the DFI treatment followed by DDI-75, DDI-50 and DF-PRD-50 treatments. Although, D-PRD-50, DF-PRD-50 and DDI-50 received the same amount of water, D-PRD-50 had a higher yield. In furrow, FFI resulted in the highest yield followed by FPRD-50 and FAF-50. The lowest water use efficiency (WUE) was obtained from the DFI while the highest WUE was found in DPRD-50 in drip system. The lowest WUE was found in FFI, and the highest WUE was in FPRD-50 treatment under furrow. The threshold crop water stress index (CWSI) was 0.26 for drip and 0.38 for furrow prior to irrigation. There was a significant relation between yield and CWSI. A high correlation was found between CWSI and leaf area index. The results revealed that DFI for the drip and FFI for the furrow were recommended. Under water scarcity conditions, DDI-75 and D-PRD-50 treatments can be recommended. © 2014 Elsevier B.V. TOVAG-109O693 The authors would like to thank the Turkish Scientific and Technical Research Council (TUBITAK) for its financial support for the project TOVAG-109O693.

In this study, 1 full irrigation regime (100% of crop evapotranspiration, I100) and 2 defcit irrigation regimes (70%, I70, and 50%, I50) were evaluated in a Rio Red grapefruit (Citrus paradisi Macfad. ‘Rio Red’) orchard in Adana, Turkey. Fruit yield, leaf water potential (LWP), and soil water depletion (SWD) were measured among trees from each treatment. Actual evapotranspiration was calculated in 3 ways, using 2 energy balance methods (eddy correlation and Bowen’s ratio) and water balance. Evapotranspiration rates of I70 and I50 treatments were 10% and 18% less than I100, respectively. Average irrigation amount for I50 was less than half of the average irrigation amount for I100. Considering that yield for the experimental treatments did not change statistically signifcantly, the I50 treatment provided about 50% more irrigation water savings than full irrigation conditions. Grapefruit tree LWP was highly correlated to soil water status and signifcantly associated with irrigation treatment. Average LWP values for treatments were –2.70 MPa for I100, –2.96 MPa for I70, and –3.28 MPa for I50. LWP increased up to a threshold level equivalent to 60%–66% of SWD, above which LWP decreased linearly with a continuous increase of SWD. Tis indicates that an average LWP of –3.28 MPa can be allowed for grapefruit under these experimental conditions while keeping the crop yield at that of full irrigation levels. Te research fndings showed that an enhanced understanding of physiological parameters is essential for irrigation scheduling of fruit plants. Tese will result in obtaining the optimum yield of fruit while conserving water. In this study, 1 full irrigation regime (100% of crop evapotranspiration, I100) and 2 defcit irrigation regimes (70%, I70, and 50%, I50) were evaluated in a Rio Red grapefruit (Citrus paradisi Macfad. ‘Rio Red’) orchard in Adana, Turkey. Fruit yield, leaf water potential (LWP), and soil water depletion (SWD) were measured among trees from each treatment. Actual evapotranspiration was calculated in 3 ways, using 2 energy balance methods (eddy correlation and Bowen’s ratio) and water balance. Evapotranspiration rates of I70 and I50 treatments were 10% and 18% less than I100, respectively. Average irrigation amount for I50 was less than half of the average irrigation amount for I100. Considering that yield for the experimental treatments did not change statistically signifcantly, the I50 treatment provided about 50% more irrigation water savings than full irrigation conditions. Grapefruit tree LWP was highly correlated to soil water status and signifcantly associated with irrigation treatment. Average LWP values for treatments were –2.70 MPa for I100, –2.96 MPa for I70, and –3.28 MPa for I50. LWP increased up to a threshold level equivalent to 60%–66% of SWD, above which LWP decreased linearly with a continuous increase of SWD. Tis indicates that an average LWP of –3.28 MPa can be allowed for grapefruit under these experimental conditions while keeping the crop yield at that of full irrigation levels. Te research fndings showed that an enhanced understanding of physiological parameters is essential for irrigation scheduling of fruit plants. Tese will result in obtaining the optimum yield of fruit while conserving water.

This study was conducted in order to compare the alternate every other furrow surge irrigation (AFO) to the every furrow surge irrigation (EFO), under Mediterranean conditions in Turkey at the Cukurova University experimental farm. The experiment was undertaken in order to determine the appropriate throughput at furrow lengths of 110 m. In general, depending on the water flow (0.87-1.16 L/s) and the duration of the irrigation application (228-272 min), there may be differences on the amount of water under the same flow rates with the use of similar forms of operating furrow application of the AFO, which was determined to be more advantageous than the application of the EFO. The application efficiencies were quite similar by 78% in the EFO and 84% in the AFO, respectively. The reason for these high efficiencies was found to be due to the lacking irrigation application concerning the time of irrigation and the rate of water flow. Significant water savings were achieved by AFO compared to the EFO technique in the field by using the furrows in turns at each irrigation operation. The average soybean yields for both two years were 252 kg/da for the EFO and 259 kg/da for the AFO application. The results of the experiment revealed that the AFO furrow irrigation technique was the appropriate surface irrigation technique for the studied area.

This study examines the effects of different partial root zone drying and deficit irrigation regimes on seed and oil yield quality and water use of drip-irrigated sunflower under field conditions in 2006 and 2007 in the eastern Mediterranean region of Turkey. Irrigation regimes consisted of full irrigation (FI-100) and three deficit irrigation treatments (DI-25, DI-50, DI-75), and partial root zone drying (PRD-50) and rain-fed treatment (RF). Irrigation regimes significantly (P

This study was carried out to determine the crop water stress index (CWSI) for drip irrigated cotton grown on a heavy clay texture soil (Palexerollic Chromoxerert) under semi-arid climatic condition of East Mediterranean region for three years (2005 to 2007) in Adana, Turkey. Four irrigation treatments designated as full (I100) with no water stress and slight (DI70), moderate (DI50) and strong water stress (continuous stress, dry land) (DI00) were tested. The treatments of DI70 and DI50 received water amount of 70 and 50% of the control treatment and the DI00 was not irrigated except for germination water given at the beginning of the growing season. Irrigation was initiated when leaf water potential (LWP) reached to -15 bar for full (I100), -17 bar for DI70 and -20 bar for DI50 irrigation treatments. After first irrigation, all the treatments were irrigated at one week interval. The deficit irrigation affected, the irrigation water use, seed cotton yield, dry matter and some yield components such as plant height and number of boll per plant of cotton. Average values of water use, seed cotton yield, dry matter and water use efficiency of full irrigated cotton were 578 mm, 3.28 tha-1, 13.44 tha-1 and 0.59 kgm-3, respectively. CWSI values were calculated from the measurements of canopy temperatures by infrared thermometer (IRT), ambient air temperatures and vapor pressure deficit values for all the irrigated treatments. A non-water stressed baseline (lower baseline) equation for cotton was developed using canopy temperature measured from full irrigated plots as, Tc −Ta = −1.7543VPD +1.56; R2=0.5327 and the non-transpiring baseline (upper baseline) equation was built using canopy temperature data taken from continuous stress plots as, Tc −Ta = −0.0217VPD + 3.2191. The trends in CWSI values were consistent with the varying soil water content due to the deficit irrigation programs. The relationships between mean CWSI and plant parameters considered in this study were linear except for irrigation water amount. Both dry matter and seed cotton yield decreased with increased soil water deficit. Seed cotton yield (SY) and seasonal mean CWSI values relationship were obtained as, SY = −2.3552CWSI + 3.5657 ; R2=0.499. This relationship can be used to predict the seed cotton yield. The results suggest that the cotton crop for this particular climate and soil conditions, should be irrigated when CWSI approaches 0.36. The CWSI approach, according to results of this study, can be accepted as a useful tool to schedule irrigations for cotton.Key words: Crop water stress index (CWSI), evapotranspiration, cotton, drip irrigation.

This study examines the effects of different irrigation regimes on yield and water use of pepper irrigated by a drip system under field conditions during the 2004 growing season at the Soil and Water Resources Research Institute in Tarsus, Turkey under Mediterranean climatic conditions. The field trials consisted of three irrigation intervals (IF1:20±2, IF2:40±2 and IF3:60±2 mm of cumulative pan evaporation) and evaluated by three irrigation levels (DI1=0.50, DI2=0.75 and DI3=1.00). Both the irrigation levels (DI) and intervals (IF) had significantly different effects on pepper yields. The maximum and minimum yields were obtained from the IF1DI3 and IF3DI1 treatment plots as 35920 and 21390 kg ha-1, respectively. The yields and yield components decreased as irrigation levels decreased for each irrigation interval. However, the larger irrigation interval (IF3) resulted in lower yields with all irrigation levels. Pepper seasonal evapotranspiration varied from a low 327 mm in the more stressfull treatment (IF3DI1) to a high 517 mm in the well irrigated control (IF1DI3). Significant linear relations were found between the pepper yield and the total water use for each irrigation interval. Irrigation intervals resulted in similar water use in the treatments with the same irrigation level. Water use efficiency (WUE) and irrigation water use efficiency (IWUE) values were significantly influenced by the irrigation intervals and levels. WUE ranged from 6.0 kg m-3 in IF3DI2 to 7.8 kg m-3 in the IF1DI1. The maximum IWUE was observed in IF1DI1, and the minimum IWUE was in IF3DI3 treatment. Both irrigation levels and frequencies had significantly different effects on quality parameters such as the first and second quality yield, number of fruit, mean fruit weight, pepper length and width, as well as plant height at harvest. In conclusion, the IF1DI3 irrigation regime is recommended for field grown pepper in order to attain higher yields with improved quality. Economic evaluation revealed that full irrigation treatment (IF1DI3) generated the highest net income. However, under water scarcity conditions, IF1DI2 treatment can provide an acceptable net income.Key words: Pepper, deficit irrigation, water use efficiency, yield response factor, economic evaluation.

A field study on cotton (Gossypium hirsutum L., cv.) was carried out from 2005 to 2008 in the Çukurova Region, Eastern Mediterranean, Turkey. Treatments were designated as I100 full irrigation; DI70, DI50 and DI00 which received 70, 50, and 0% of the irrigation water amount applied in the I100 treatment. The irrigation water amount to be applied to the plots was calculated using cumulative pan evaporation that occurred during the irrigation intervals. The effect of water deficit or water stress on crop yield and some plant growth parameters such as yield response, water use efficiencies, dry matter yield (DM), leaf area index (LAI) as well as on lint quality components was evaluated. The average seasonal evapotranspiration ranged from 287±15 (DI00) to 584±80mm (I100). Deficit irrigation significantly affected crop yield and all yield components considered in this study. The average seed cotton yield varied from 1369±197 (DI00) to 3397±508kgha-1 (I100). The average water use efficiency (WUEET) ranged from 6.0±1.6 (I100) to 4.8±0.9kgha-1mm-1 (DI00), while average irrigation water use efficiency (WUEI) was between 9.4±3.0 (I100) and 14.4±4.8kgha-1mm-1 (DI50). Deficit irrigation increased the harvest index (HI) values from 0.26±0.054 (I100) to 0.32±0.052kgkg-1 (DI50). Yield response factor (Ky) was determined to be 0.98 based on four-year average. Leaf area index (LAI) and dry matter yields (DM) increased with increasing water use. This study demonstrated that the full irrigated treatment (I100) should be used for semiarid conditions with no water shortage. However, DI70 treatment needs to be considered as a viable alternative for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited. © 2010 Elsevier B.V. European Geosciences Union: INCO-CT-2004-509087 The authors would like to gratefully acknowledge the European Union for providing funding through the INCO-CT-2004-509087 STREP DIMAS project. The authors are also thankful to Prof. Elias Fereres, coordinator of the project in the Agronomy Department, University of Cordoba, Spain, for his help and suggestions during the study. Furthermore, we thank Dr. Kenan Diker, Water Quality Control Division, Colorado Department of Public Health and Environment, 80246, Denver, CO, USA and Dr. Ann Diker, Assistant Professor, Metropolitan State College of Denver, Denver, CO, USA, for their help in preparing the manuscript.

This study investigates the impact of the expected climate changes in the Apulia region (Southern Italy) for the next 100 years on the climatic water balance variations, climatic classifications and crop water requirements. The overall results indicated that an increase of temperature, in the range between 1.3 and 2.5°C, is expected in the next 100 years. The reference evapotranspiration (ETo) variations would follow a similar trend; as averaged over the whole region, the ETo increase would be about 15.4%. The precipitation should not change significantly on yearly basis, although, a slight decrease in summer months and a slight increase during the winter season are foreseen. The climatic water deficit (CWD) is largely caused by ETo increase, and it would increase over the whole Apulia region in average for more than 200 mm. According to Thornthwaite and Mather climate classification (1957), the moisture index will decrease in the future, with decrease of humid areas and increase of aridity zones. The net irrigation requirements (NIR), calculated for ten major crops in the Apulia region, would increase significantly in the future. By the end of the 21st Century, the foreseen increase of NIR, in respect to actual situation, is the greatest for olive tree (65%), wheat (61%), grapevine (49%), and citrus (48%) and it is slightly lower for maize (35%), sorghum (34%), sunflower (33%), tomato (31%), and winter and spring sugar beet (both 27%). © 2010 Academic Journals.

Global warming and resulting drought is the most important constraint affecting plant production in the Mediterranean Region. Therefore, effective management of scarce water resources is of paramount importance in this region. This research was conducted to determine the optimal irrigation strategy for drip irrigated fresh market tomato grown in different soilless culture in a glasshouse in the Mediterranean Region of Turkey. Volcanic ash, peat and their mixture were used as growth media. Four different irrigation levels (WL1=75%; WL2=100%; WL3=125% and WL4=150% of Class A Pan evaporation) and two watering frequencies (once and twice daily applications) were evaluated. Highest yield and fruit number were obtained from the ash+peat mixture (1:1) with twice a day watering at WL4 irrigation level. Soluble solids of tomato fruit decreased with increasing available water. The highest irrigation water use efficiency (IWUE) value of 121.4 kg m-3 was obtained from once a day irrigation WL1 irrigation level with peat+ash (1:1). IWUE decreased in all treatments as the amount of irrigation water increased. © 2010 Academic Journals.