ORIGINAL PAPER
Effects of different irrigation interval and plant-pan coefficient
applications on yield and quality parameters of oil sunflower grown
in semi-arid climatic conditions
Nurcan Yavuz1&Nizamettin Çiftçi1&Duran Yavuz1
Received: 6 December 2018 / Accepted: 3 October 2019 # Saudi Society for Geosciences 2019
Abstract
Sustainability of plant production activities and improvement of irrigated lands in arid and semi-arid regions totally depend on efficient use of available water resources. Such an efficient use of water resources can be provided through assessment of water–yield relationships and identification of proper irrigation programs, schedules, and operational principles. There are no studies carried out to determine water–yield relations of oleic-type sunflower plants grown over large areas in Konya plain. In this study, different irrigation intervals (S) and crop-pan coefficients (Kcp) were used in drip irrigation of sunflower plants in Konya which is located at the Middle Anatolia in Turkey. The primary objective was to determine the effects of irrigation levels and intervals on yield and quality parameters of sunflower plants. Experiments were conducted in 2013–2014 growing seasons in 3 × 5 factorial design with 4 replica-tions. Three different irrigation intervals (S5:5, S10:10, and S15:15-day) and five different crop-pan coefficients (Kcp1.25:125% of pan
evaporation, Kcp1.00:100% of pan evaporation, Kcp0.75:75% of pan evaporation, Kcp0.50:50% of pan evaporation, and Kcp0.00:rain-fed
without irrigation) were used in this study. In an average of 2 years, the greatest seed yield (5481 kg/ha) was obtained from S10Kcp1.25
with the greatest water consumption (748.7 mm). As compared with S10Kcp1.25treatment, about 25% decrease was observed in yield
of Kcp0.75treatments irrigated at 5- and 10-day intervals. Such a decrease was identified as 15% in Kcp1.00treatments irrigated at
15-day intervals. Therefore, for optimum seed yields from sunflower plants grown in Konya plain, irrigation intervals should not exceed 10 days. Also, crop-pan coefficient should be taken as 1.00 for high seed yields. Again, in an average of 2 years, irrigation water use efficiency (IWUE) of the treatments varied between 0.70 and 3.70 kg/m3and water use efficiency (WUE) values varied between 0.53 and 0.75 kg/m3. The average yield response factor (ky) was identified as 1.14. Since the value is greater than 1, it was concluded that
sunflower plants were sensitive to water deficits under Konya conditions.
Keywords Deficit irrigation . Water use efficiency . Yield response factor . Drip irrigation
Introduction
Sunflower is one of the most important oil crops in the world (Skoric1992). Oils are essential nutrients for humans and play
significant roles in sustainability of daily activities. While 1 g oil supplies 9 kcal energy, the same quantity of protein and carbohydrate provides 4 kcal energy (Başalma1991).
Sunflower with high and quality oil content (40– 50%) is a significant oil crop for edible oil production both in the world and Turkey (Öztürk et al. 2008). Sunflower oil has quite high unsaturated fatty acid con-tent and low saturated fatty acid concon-tent; therefore, it has quite high nutritional values. Today, about 8.9% of world vegetable crude oil production and 44% of Turkish vegetable crude oil production are constituted by sunflower (Onat et al. 2017). It is considered as the most significant oil crop in Turkey to prevent 1 million tons of annual average oil import of the country. Konya province has the greatest sunflower production ratio (17.8%) of Turkey. While the sunflower production Responsible Editor: Haroun Chenchouni
* Nurcan Yavuz ncivicioglu@selcuk.edu.tr Nizamettin Çiftçi nciftci@selcuk.edu.tr Duran Yavuz dyavuz@selcuk.edu.tr
1 Department of Farm Building and Irrigation, Faculty of Agriculture, University of Selcuk, Konya, Turkey
was practiced over 23.4 thousand hectares in 2010, the area increased to 60 thousand hectares in 2014. The production sites doubled in 5 years. The amount of production in 2010 (46,764 tons) also increased fivefold by the year 2014 (263,581 tons) (Anonymous 2015). Konya province has about 8% of total agricultural lands of Turkey. The province has a dry climate and water resources of the Konya plain are quite limited. Long-term annual average precipitation of the plain is 323 mm and only 90–100 mm of such amount falls during vegetation period (May–September) (Seymen et al. 2019). Therefore, diversity in plant production activities, yields and quality in the plain are totally de-pendent on irrigation.
In Konya plain, about 500,000 ha area accounting for 20–25% of total arable land potential has been irrigated. Hig h water-co nsuming cro ps suc h as sugar beet (900 mm), carrot (1000 mm) and alfalfa (1000 mm) are widely grown over the plain. Sunflower has quite less crop water requirement than many other crops. Howell et al. (2015) in a study carried out in Texas reported crop water consumption of sunflower as 638 mm. Abdou et al. (2011) found that the highest crop water consumption values of 532 mm from the of June sown sunflower with irrigation scheduled under 1.2 cumulative pan evapora-tion, Egypt. Ghani et al. (2000) in a study carried out in Pakistan, practiced 2, 4, and 6 irrigations for sunflower plants and reported significant effects of number of irri-gations on head diameter, number of seeds per head and thousand-seed weights and indicated the greatest seed yield as 311.9 kg/da for 6 irrigations. Süllü (2013) and Sezen et al. (2011) indicated significant effects of irriga-tion intervals and different irrigairriga-tion regimes on yield and yield parameters and reported the greatest yield for 100% (full) irrigation treatments. Despite the highest yields in full-irrigation conditions, sunflower was found to be re-sistant to short-term water deficits (Doorenbos and Kassam1979). Deficit irrigation (DI) is a significant strat-egy in which plants are exposed to water stress for certain periods. The strategy may reduce production costs and thus increase income levels from agricultural activities. It can also improve profitability in places where water costs are high and water resources are limited (English and Raja1996).
The present study was conducted with sunflower plants grown in Konya plain to determine plant water consumptions, to create irrigation programs with mini-mum yield losses under deficit irrigation conditions, and to elucidate water–yield relations and quality parameters at different irrigation intervals. The ultimate goal was to provide beneficial data to sunflower producers of the region, to determine proper plant-pan coefficients to be used in Class-A Pan method for irrigation water
quantities and finally to provide maximum yields with optimum irrigation programs.
Materials and methods
Research site
Experiments were conducted over the experimental fields of Saricalar Experimental Station of Selcuk University in 2013 and 2014. The research site is located at 38° 05′ North lati-tudes and 32° 36′ East longilati-tudes. The average altitude of the site is around 1006 m.
Climate data for the research site was supplied from a por-table climate station installed over the experimental fields. The total precipitation was 226.2 mm in 2013 and 420.3 mm in 2014. The total precipitation during the vegetation period was measured as 68.6 mm in 2013 and as 113.4 mm in 2014. The greatest evaporation in both years was measured in July (respectively as 244.4 and 261.4 mm) (Table1).
The parent material of experimental soils was lake bed and composed of transported and deposited alluvial material. Upper soil layers have silty-clay texture and lower layers have clay texture. Soil bulk density values vary between 1.25 and 1.31 g/cm3and field capacity values vary between 31.6 and 36.2%. Available water holding capacity of 0–90 cm soil layer is 153.8 mm. Soil physical characteristics (texture, bulk den-sity, field capacity, permanent wilting point, available water holding capacity) and chemical characteristics (pH, total salt, and organic matter content) are provided in Table2. Soil in-filtration rate was measured as 16 mm/h.
Irrigation system
Irrigation water was supplied from a nearby deep-well with a 3″ line shaft vertical deep-well pump. Drip irrigation was used in irrigation practices. Dripper tests were performed with 4 l/h dippers at 1 atm. Operational pressure to determine dripper spacing and wetted sections. Tests revealed a wetted diameter of 60 cm under 30 cm from the soil surface. Therefore, dripper spacing was selected as about 66% of that wetter diameter (40 cm) (Yıldırım2003). Percentage of wetted area under a single dripper was calculated by dividing wetted diameter with lateral spacing (Keller and Bliesner 1990; Çetin and Uygan2008; Yıldırım and Korukçu1999). The wetted diam-eter was 60 cm and lateral spacing was 70 cm in this study, thus percentage of wetted area was calculated as about 85%.
Drip irrigation system was composed of a control unit (in-cluding hydro-cyclone, fertilizer tank, disc filter, control valves, and manometers), 16 mm laterals with 4 l/h drippers operating at 1 atm operational pressure, 63 mm PE main line, and 40 mm manifold lines. To measure the irrigation water
quantities, ¾″ water meters were placed at the entrance of each plot.
Experimental design and treatments
Experiments were conducted in 3 × 5 factorial designs with 4 replications. Main treatments were composed of different irri-gation intervals (S5:5 days, S10:10 days, S15:15 days);
sub-treatments were composed of different plant-pan coefficients corresponding to different irrigation levels (Kcp1.25:125% of
pan evaporation; Kcp1. 00:100% of pan evaporation;
Kcp0.75:75% of pan evaporation; Kcp0.50:50% of pan
evapo-ration, and Kcp0.00:non-irrigated, rain-fed treatment)
(Table3).
Experimental plots were 10 m long and 2.8 m wide (with 4 plant rows in each plot). A lateral line was placed for each plant row. About 2.5 m spacing was provided between the blocks and 2.1 m spacing was provided between the plots. Variation in soil moisture was monitored with Profile-Probe (Delta-T Pr2) moisture meter calibrated with gravimetric method for 1 m soil profile. To determine deep percolations, the soil moisture at 90–120 cm soil layer was monitored through gravimetric method. Profile-Probe was used for daily readings and samples were taken every 5 days for the gravi-metric method.
Amount of irrigation water to be applied in each irrigation treatment was calculated by using Eq. (1) and irrigation water was applied accordingly (Çetin et al.2002; Ertek and Kanber
2003). Plant coefficient in Eq. (1) (kc) and pan coefficient (kp)
Table 1 Long-term and 2013–2014 climate data for the research site
Years Climate parameters Months
May June July August September Annual
T o t a l / average
2013 Mean temperature (°C) 17.6 20.8 22.6 22.7 17.5 18.8
Total precipitation (mm) 46.4 12.4 5.6 0.6 3.6 226.2
Total evaporation (mm) 169.2 214.7 244.4 223.7 148.8 1212.2 Mean relative humidity (%) 45.9 36.3 34.0 32.3 37.8 53.3
Mean wind speed (m/s) 1.9 2.7 3.4 2.9 2.2 1.9
2014 Mean temperature (°C) 15.4 19.5 24.7 24.9 18.3 12.7
Total precipitation (mm) 31.6 55.6 9.6 2.8 13.8 420.3
Total evaporation (mm) 145.1 188.6 261.4 260.4 145.8 1217.8 Mean relative humidity (%) 53.1 46.8 35.0 32.2 57.9 58.5 *
Mean wind speed (m/s) 2.3 2.6 3.2 3.1 2.3 2.1
Long-term averages
(1960–2017) Mean temperature (°C)Total precipitation (mm) 15.743.8 20.122.9 23.46.8 22.85.5 18.411.0 11.5322.5 Total evaporation (mm) 155.5 211.8 269.9 250.6 173.2 1285 Mean relative humidity (%) 55.9 48.4 42.1 42.9 48.0 59.7 *
Mean wind speed (m/s) 2.2 2.5 2.8 2.6 2.1 2.2
Table 2 Physical and chemical properties of the experimental soils
Soil depth (cm) pH EC dS/m Organic material (%) Texture class Bulk density (g cm−3) Field capacity (FC) Permanent wilting point (PWP)
Available soil water content % mm % mm % mm 0–30 7.74 1.45 1.62 SiCL 1.31 31.6 124.2 20.7 81.3 10.9 42.9 30–60 7.86 1.32 1.45 SiC 1.29 33.7 130.4 19.3 74.7 14.4 55.7 60–90 8.02 1.21 1.38 C 1.26 34.8 131.5 20.2 76.3 14.6 55.2 90–120 7.88 2.10 0.71 C 1.25 36.2 135.7 20.8 78.0 15.4 57.7 Total (0–90 cm) 386.1 232.3 153.8 Total (0–120 cm) 521.8 310.3 211.5
was expressed as plant-pan coefficient (kcp) (Ertek et al.2004;
Sezen et al.2006). Irrigation water quantities calculated with Eq. (1) was applied through a water meter placed at the en-trance of each plot.
I ¼ Ep Kcp P A ð1Þ
whereI is the amount of irrigation water (l), A is the plot size (m2),P is the wetted area percentage (%), Epis the cumulative
evaporation from Class-A Pan (mm) (S5, the total 5 day
cu-mulative evaporation;S10, the total 10-day cumulative
evap-oration;S15, the total 15-day cumulative evaporation), andKcp
is plant-pan coefficients (1.25, 1.00, 0.75, 0.50, and 0.00).
Agricultural practices
Oleic-typeSirena sunflower cultivar was used as the plant material. Seeds were sown on 29 of April in both years with 4-row pneumatic seed drill to about 3 cm depth. About 20 kg/ da diammonium phosphate (DAP) fertilizer was applied be-fore sowing and 200 kg/ha ammonium nitrate (33% nitrogen) was applied when the plants had 4–5 leaves.
For homogeneous germination and emergence, 20-mm irrigation water was applied to all treatments in both years just after sowing (30 April) through sprinkler irri-gation. Also, 20-mm irrigation water was applied to all treatments in both years after hoeing for homogeneous distribution of granulated fertilizer. In both years, irriga-tion treatments were initiated at the end of rainy season when 45–50% of available moisture was depleted. Irrigation treatments were initiated on 22 June in 2013 and on 27 June in 2014. Soil moisture was monitored through gravimetric method. Except for rain-fed treat-ment without any irrigation (Kcp0), soil moisture level
was brought to field capacity with irrigations. A total of 12, 6, and 4 irrigations were performed respectively in 5-, 10-, and 15-day intervals. Irrigations were termi-nated on 21 August in the first year and on 26 August in the second year.
Side effects (a rows from each side and 2m sections from the top and bottom of the plots, 6 × 1.4 = 8.4 m2) were con-sidered while harvesting the plants from the plots. Harvest was performed on 27 September in the first year and on 20 September in the second year.
Plant water consumption
The equation provided by James (1988) was used to determine plant water consumption values (Eq. (2));
ET ¼ I þ R−DPþ CP−Rf ΔS ð2Þ
whereET is the plant water consumption (evapotranspiration) (mm),I is the amount of applied irrigation water (mm), R is the effective rainfall (mm),Dpis the deep percolation (mm),
Cpis the capillary rise from the root zone (mm), Rf is the
surface runoff (mm), andΔS is the change in soil moisture (within root zone) (mm).
The I values were determined from irrigation water measurements, R from the portable climate station installed over the experimental site, and Dp values were
determined with gravimetric method. Seepage from 90 to 120 cm soil layer was considered as deep percola-tion. Experimental soils were deep soils without any drainage and salinity problems and there were not any water table problems. Therefore, there were no any cap-illary rise from the root zone and Cp was not included
in calculations. Since surface runoff is not allowed in drip irrigation, Rf was not also included in calculations.
ΔS values were taken from soil moisture measurements throughout the soil profile.
Equation (3) was used to calculateIrc(irrigation water
com-pensation) values indicating compensation rate of ET by irri-gation water applied (Howell et al.1990).
Irc¼ETI 100 ð3Þ
whereIrcis the irrigation water compensation (%), I is the seasonal irrigation water (mm), andET is the seasonal plant water consumption (mm).
Water
–yield relationships
To determine the effects of water stress on yield, water– yield relations were determined with Eq. (4) by using the relative water consumption deficit and relative yield loss values (Doorenbos and Kassam 1979).
1−YYa m ¼ ky 1−ETETa m ð4Þ
whereYais the actual yield (kg/ha),Ymis the maximum yield (kg/ha),kyyield response factor,ETais the actual plant water
consumption (mm), and ETm is the maximum plant water
consumption (mm). Table 3 Irrigation treatments
Irrigation intervals Irrigation levels S5: 5 days S10:10 days S15:15 days Kcp1.25: Plant-pan coefficient of 1.25 Kcp1.00: Plant-pan coefficient of 1.00 Kcp0.75: Plant-pan coefficient of 0.75 Kcp0.50: Plant-pan coefficient of 0.50 Kcp0.00: Plant-pan coefficient of 0.00
Water use efficiency
For assessment of an irrigation method or an irrigation pro-gram, water use efficiency (WUE) and irrigation water use efficiency (IWUE) values are commonly employed. Relevant parameters were calculated by using Eqs. (5) and (6) as recommended by Tanner and Sinclair (1983);
WUE ¼ETEy ð5Þ
whereWUE is the water use efficiency (kg/m3),Eyis the seed yield (kg/ha), andET is the seasonal plant water consumption (m3/ha)
IWUE ¼Ey
I ð6Þ
whereIWUE is the irrigation water use efficiency (kg/m3),Ey
is the seed yield (kg/ha), andI is the seasonal irrigation water quantity (m3/ha).
Statistical analyses
Seed yield, plant height, stalk thickness, thousand-seed weight, dry matter yield, oil ratio, and oil yield values of experimental treatments were subjected to variance analysis (ANOVA). Analyses revealed that average of 2 years should be taken for quality parameters. Treatment means were com-pared with Duncan’s multiple range tests. The differences be-tween the treatments were tested at 1 and 5% significance levels. Since also irrigation interval × year, crop-pan coeffi-cient × year and irrigation interval × crop-pan coefficoeffi-cient × year interactions were not found to be significant; Duncan’s multiple range test was applied to average of 2 years. Regression equations were developed for the relationships between irrigation water quantities, plant water consumption and yield values.
Results and discussion
Water
–yield relations
Total evaporation during the irrigation season from Class-A-Pan was measured as 551 mm/60 days in 2013 and 544 mm/ 60 days in 2014. Amount of water evaporated from the pan throughout the irrigation season was calculated as 9 mm/day and the values were quite close to each other in both years. Measurements of the amount of water evaporated from Class-A Pan started on 22 June and ended on 21 Class-August in 2013 and started on 27 June and ended on 26 August in 2014. The greatest temperatures were observed throughout the periods.
The greatest amount of irrigation water was applied in Kcp1.25treatment at all three irrigation intervals. Total amount
of irrigation water applied in irrigation treatments varied be-tween 40.0 and 700.4 mm in 2013 and bebe-tween 40.0 and 680.0 mm in 2014. Kolsarıcı (2004) carried out a study in Ankara with the similar climate conditions and reported the amount of applied irrigation water as 746 mm. More irrigation water was applied than the maximum irrigation water applied in this study. This may be due to the efficiency of the irrigation method used or the soil moisture content may have been followed by a different method. In an average of 2 years, the total amount of applied irrigation water at Kcp1.25and Kcp1.00
treatments was respectively measured as 690.2 and 573.9 mm. The amount in Kcp1.00treatments was about 17% less than the
amount in Kcp1.25treatments. Dorsan et al. (1994) indicated
decreasing seasonal water consumption, yield, head diameter, and oil ratio for sunflowers with decreasing irrigation water quantities, but recommended 20% water deficit under limited water resources conditions.
Maximum plant water consumption was observed in S5Kcp1.25 treatment (751.5 mm) in the first year and in
S10Kcp1.25treatment (756.5 mm) in the second year
(Table4). Sezen et al. (2011) and Kolsarıcı (2004) reported seasonal plant water consumption of sunflower as 689 mm and 768.7 mm in full-irrigation treatments, respectively. In full-irrigation applications where the irrigation interval is not long, the plant is not exposed to water stress and maximum plant water consumption occurs. When the plant water need is met completely,ETaandETmaxwill be equal. Under limited
irrigation conditions, theETavalue of the plant falls below the
ETmaxvalue (Doorenbos and Kassam1979).
In an average of 2 years, low ETavalues were obtained from Kcp0treatments. In S5and S10treatments, the change
inETavalues calculated for Kcp1.25 and Kcp1.00 was above
90%. Similarly, in S15treatment, 125% of pan evaporation
(Kcp1.25) was not influenced by the lengthy irrigation
inter-vals. However, theETavalue calculated for S15Kcp1.00
treat-ment decreased by about 16% as compared with the greatest ETavalue because the available soil moisture was close to the
wilting point before the irrigation due to long irrigation inter-val (Fig.1).
Ircvalues at all three irrigation intervals were over 80% in
full-irrigation treatments (Kcp1.25 and Kcp1.00). In other
words, large portion of sunflower water consumption (more than 80%) was compensated by irrigation water. Such values indicated that sunflower could not be grown in the region without irrigation. Under rain-fed conditions, a yield loss of 70% was evident. Similarly, Yavuz et al. (2015) reported the greatestIrcvalue for pumpkin seed plants in Konya province
as 82%. The greatest seed yield was obtained from the treat-ments with the maximum plant water consumptions in both years. In 2013, the greatest seed yield was obtained from S5Kcp1.25(5524 kg ha−1) treatment and the lowest value was
obtained from rain-fed treatment (1223 kg ha−1). In 2014, the greatest seed yield was obtained from S1 0Kcp1 . 2 5
(5365 kg ha−1) treatment and the lowest value was obtained from again the rain-fed treatment (1356 kg ha−1). Karam et al. (2007) and Howell et al. (2015) reported the greatest yield for full-irrigation (100%) treatment (5360 kg ha−1, 3080 kg ha−1). Kcp1.25and Kcp1.00treatments with 5-day and 10-day
irriga-tion intervals had the greatest seed yields. In addiirriga-tion, there were reductions of up to 40% in seed yield due to the large irrigation intervals and water stress in the Kcp0.75and Kcp0.50
treatments with 15-day irrigation intervals. Süllü (2013) indi-cated significant effects of irrigation intervals and levels on yield and yield parameters and reported the greatest yield for full-irrigation (100%) treatment at 6 day intervals (4910 kg ha−1). In Turkish Statistical Institute (TUIK) records,
average seed yield for sunflower plants in Konya province was reported as 4430 kg ha−1. The present seed yields from full-irrigation treatments were higher than the averages for Konya province. The difference was because of well-designed irrigation programs and drip irrigations. As com-pared with full-irrigation treatments, about 75% yield loss was observed in rain-fed treatment.
Slope of the lines indicating the seed yields of the treat-ments with pan coefficients of 1.25 and 1.00 was more hori-zontal in all three irrigation intervals. However, the descent in lines was more remarkable from Kcp value of 1.00 to 0.75. As can be seen from the Fig.2, similar seed yields were obtained from 5 and 10-day irrigation intervals. However, as compared with 5 and 10-day intervals, seed yields always decreased in 15-day interval of all treatments.
Table 4 Irrigation,ETa, and seed yield values in different years and treatments Years Treatments Number of
irrigations Applied irrigation water (I) (mm) Effective rainfall (mm) ETa (mm) Irc (%) Seed yield kg ha−1 Relative ETa (%)
Relative seed yield (%) IWUE kg m−3 WUE kg m−3 2013 S5Kcp1.25 12 700.4 68.6 751.5 88.4 5524 100.0 100.0 0.79 0.73 S5Kcp1.00 12 583.4 68.6 694.0 84.1 5385 92.3 97.5 0.92 0.78 S5Kcp0.75 12 466.3 68.6 593.1 78.6 3923 78.9 71.0 0.84 0.66 S5Kcp0.50 12 349.2 68.6 502.1 69.5 3284 66.8 59.5 0.94 0.65 S5Kcp0.00 – 40.0 68.6 224.4 17.8 1223 29.8 22.1 3.05 0.54 S10Kcp1.25 6 700.4 68.6 740.8 87.9 5502 98.5 99.6 0.79 0.74 S10Kcp1.00 6 583.4 68.6 698.5 83.5 5133 92.9 92.9 0.88 0.73 S10Kcp0.75 6 466.3 68.6 606.6 76.9 4227 80.7 76.5 0.90 0.70 S10Kcp0.50 6 349.2 68.6 506.6 68.9 3432 67.4 62.1 0.98 0.68 S10Kcp0.00 – 40.0 68.6 224.4 17.8 1280 29.8 23.2 3.20 0.57 S15Kcp1.25 4 700.4 68.6 678.6 91.4 4675 90.3 84.6 0.67 0.69 S15Kcp1.00 4 583.4 68.6 626.1 86.6 4710 83.3 85.3 0.81 0.75 S15Kcp0.75 4 466.3 68.6 579.6 80.5 3970 77.1 71.9 0.85 0.68 S15Kcp0.50 4 349.2 68.6 482.3 72.4 3260 64.1 59.0 0.93 0.68 S15Kcp0.00 – 40.0 68.6 224.4 17.8 1239 29.8 22.4 3.08 0.55 2014 S5Kcp1.25 12 680.0 113.4 742.0 87.0 5365 98.0 98.3 0.79 0.72 S5Kcp1.00 12 564.4 113.4 700.3 80.6 5051 92.5 92.5 0.89 0.72 S5Kcp0.75 12 448.8 113.4 590.1 76.1 4312 78.0 79.0 0.96 0.73 S5Kcp0.50 12 333.2 113.4 540.2 61.7 3451 71.4 63.2 1.04 0.64 S5Kcp0.00 – 40.0 113.4 263.2 15.2 1738 34.7 31.8 4.33 0.66 S10Kcp1.25 6 680.0 113.4 756.5 83.3 5459 100.0 100.0 0.80 0.72 S10Kcp1.00 6 564.4 113.4 701.2 80.5 4950 92.6 90.7 0.88 0.71 S10Kcp0.75 6 448.8 113.4 599.1 74.9 4038 79.1 74.0 0.90 0.67 S10Kcp0.50 6 333.2 113.4 550.1 60.6 3136 72.7 57.5 0.94 0.57 S10Kcp0.00 – 40.0 113.4 263.2 15.2 1530 34.7 28.0 3.83 0.58 S15Kcp1.25 4 680.0 113.4 696.1 86.6 4983 92.0 91.3 0.73 0.72 S15Kcp1.00 4 564.4 113.4 640.5 82.1 4593 84.6 84.1 0.81 0.72 S15Kcp0.75 4 448.8 113.4 589.2 76.2 3500 77.8 64.1 0.78 0.59 S15Kcp0.50 4 333.2 113.4 499.7 66.7 3227 66.0 59.1 0.97 0.64 S15Kcp0.00 – 40.0 113.4 263.2 15.2 1356 34.7 24.8 3.38 0.51
As the average of 2 years, irrigation water use effi-ciency (IWUE) values of irrigation treatments varied between 0.7 and 3.7 kg/m3. The greatest IWUE value was observed in rain-fed treatments and values decreased with increasing amount of irrigation water. The IWUE of S10Kcp1.25 treatment with the greatest
seed yield was calculated as 0.79 kg/m3. Similarly, Sezen et al. (2011) reported IWUE values as between 0.57 and 1.80 kg/m3. Increasing irrigation water quanti-ties did not increase in the yield at the same rates. As can be seen from the Fig. 3, plant water consumption and seed yield lines for 5- and 10-day intervals were quite close to each other. In this case, it can be stated that there were not any significant differences between 5- and 10-day intervals with regard to water consump-tion and seed yield. Seed yields of treatments with Kcp
coefficients of 1.25 and 1.00 decreased parallel to water consumptions at different irrigation intervals. However, such compliance was not observed for crop-pan coeffi-cients of 0.75 and 0.50.
Water use efficiency (WUE) values of irrigation treat-ments varied between 0.53 and 0.75 kg/m3. The greatest WUE was observed in S5Kcp1.00 treatment and the
low-est WUE was observed in rain-fed treatment. Frequent water applications in drip irrigation positively influence plant water consumptions. When the irrigations are per-formed before the soil moisture approaches to perma-nent wilting point, plants will not experience a water stress; then, yields will increase accordingly. When plant-pan coefficient of 1.00 indicates full-irrigation without any deficits. Therefore, the greatest yield per unit of irrigation water was obtained from S5Kcp1.00
treatment. Similarly, Fan et al. (2014) reported WUE of sunflower plants in China as 0.78 kg/m3; Lamm et al. (2011), in a study carried out in Kansas, reported WUE values between 0.61 and 0.82 kg/m3; Demir et al. (2006), in a study carried out in Bursa province, report-ed WUE as 0.61 kg/m3.
Yield and quality parameters
Yield and quality parameters (thousand-seed weight, oil ratio, oil yield, plant height, and stalk thickness) of oleic-type sun-flower plants were also assessed in this study.
While the irrigation intervals and pan coefficients had sig-nificant effects on average yields (P < 0.01), effects of irriga-tion interval × crop-pan coefficient interacirriga-tions were not found to be significant (Table 5). Similarly, Sezen et al. (2013) reported significant effects of different irrigation levels on sunflower seed yields at 1% level.
Based on seed yield values, 5- and 10-day irrigation inter-vals were placed in the first group (a) and 15-day irrigation interval was placed in the second group (b). According to Duncan’s multiple range tests, the differences in seed yields of 5- and 10-day irrigation intervals were not significant (P > 0.01). Although the greatest yield was obtained from Kcp1.25 treatments (5251 kg ha−1), the differences from
Kcp1.00treatments were not found to be significant (Table6).
The differences in thousand-seed weight, stalk thickness, oil ratio, oil yield, and dry matter ratio of 5 and 10-day irriga-tion intervals were not found to be significant at 1 and 5% levels. The 15-day irrigation intervals were significantly dif-ferent from 5-day irrigation intervals with regard to quality parameters except for oil ratio, dry matter ratio, and stalk thickness. Although significant differences were not observed in yield values of 15-day irrigation interval of full irrigations, significant differences were observed in some quality param-eters of 5-day intervals. Longer irrigation intervals negatively influenced quality attributes. The differences in seed yield, thousand-seed weight, plant height, stalk thickness, oil ratio, oil yield, and dry matter ratio of Kcp1.25 and Kcp1.00
treat-ments were not found to be significant at 1 and 5% levels. The greatest oil yields were obtained from Kcp1.25
treat-ments (2905 kg ha−1) and the lowest values were obtained from rain-fed treatments (841 kg ha−1). About 400% increase was achieved in oil yield with full-irrigation treatments. The effects of crop-pan coefficient on oil yields were found to be significant at 1% level (P < 0.01) and the effects of irrigation intervals at 5% level (P < 0.05). On the other hand, effects of irrigation interval × crop-pan coefficient interaction on oil yields were not found to be significant. Results of correlation analyses and correlation coefficients for the relationships of yield parameters with irrigation water and plant water con-sumptions are provided in Table7. Irrigation water and plant water consumption had highly significant positive correlations with seed yield, thousand-seed weight, oil yield, plant height, and stalk thickness at 1% level. However, irrigation water and plant water consumption had significant negative correlations with oil ratio and dry matter ratio at 1% level. Decreasing dry matter contents and oil ratios were observed with increasing irrigation water quantities and plant water consumption values. On the other hand, increasing irrigation water Fig. 2 The relationship between seed yield and irrigation water
quantities and plant consumptions had positive impacts on the other quality attributes.
Yield response factor (
k
y)
The equations yielding the relationships between irrigation water and seed yield, determination coefficient (R2
) for 2013 and 2014, and average of 2 years revealed a strong linear relationship between irrigation water and seed yield at 1% level. Seed yields increased with increasing irrigation water quantities. Several other researchers also reported linear rela-tionships between irrigation water and seed yield and between seasonal water consumption and seed yield of sunflower plants (Kolsarıcı2004; Sezen et al.2011).
Regression analyses were performed on seasonal plant wa-ter consumptions and seed yields to dewa-termine yield response factor (ky). Results are presented in Fig. 4 for experimental
years separately and average of 2 years. The yield response factor at 99% confidence was identified as 1.12 for 2013 and 1.15 for 2014 in all treatments (Fig.4d). The value was cal-culated as 1.14 for the average of 2 years. Sezen et al. (2011)
reported yield response factor for drip-irrigated sunflower plants as 1.12 in the East Mediterranean part of Turkey.
Doorenbos and Kassam (1979) indicated that plants were sensitive to water deficits whenky> 1. Since presentkyvalues
for separate years and average of 2 year were greater than 1, it was understood that sunflower plants were sensitive to water deficits under Konya conditions. Despite the insignificant dif-ferences in yield values of Kcp1.25and Kcp1.00 treatments,
such a case was more remarkable in Kcp0.75 and Kcp0.50
treatments.
Conclusion
In present study, effects of different irrigation levels and irri-gation intervals on yield and quality parameters of oleic-type sunflower plants were investigated under Konya provincial conditions for 2 years. The differences in seed yield, thousand-seed weight, plant height, stalk thickness, oil ratio, oil yield, and dry matter ratios of Kcp1.25and Kcp1.00
treat-ments were not found to be significant at 1 and 5% Table 5 Mean squares from the variance analyses of the yield and yield components
Source of variation d.f. Seed yield (kg ha−1) Thousand-seed weight (g) Oil ratio % Oil yield (kg ha−1) Plant height (cm) Stalk thickness (mm) 2013–2014 Ort. Blocks 3 145.617 ns 37.176 ns 14.210 ns 122.949 ns 64.271 ns 0.663 ns Years (Y) 1 0.800 ns 1535.821** 4.524 ns 4.272 ns 22.331 ns 0.634 ns Error 3 104.313 2.991 10.955 80.182 35.400 0.210 Irrigation interval (S) 2 1627.175** 200.433** 12.244 361.570* 125.142** 0.777 ns Crop-pan coefficient (Kcp) 4 57,311.745** 6536.003** 129.144 16,187.110** 931.945** 24.928** SxKcp 8 155.727 ns 48.113 ns 14.208 ns 81.257 ns 15.812 ns 0.416 ns SxY 2 116.721 ns 67.564 ns 5.458 ns 7.569 ns 11.176 ns 0.880 ns KcpxY 4 214.058 ns 49.429 ns 7.240 ns 62.911 ns 7.525 ns 0.633 ns SxKcpxY 8 150.002 ns 17.145 ns 4.791 ns 59.214 ns 11.922 ns 0.396 ns Error 84 283.359 30.926 8.389 107.386 7.951 0.423
ns: insignificant at P < 0.01 and P < 0.05. **Significant at P < 0.01. *Significant at P < 0.05
Table 6 Yield and quality parameters for irrigation intervals and irrigation levels Treatments Seed yield
(kg ha−1)
Thousand-seed weight (g) Oil ratio %
Oil yield (kg ha−1)
Plant height (cm) Stalk thickness (mm)
Average of 2013–2014 S5 3926a 68.9a 55.5a 2150a 106.3a 15.9a
S10 3869a 68.8a 56.4a 2157a 100.8b 15.6a
S15 3551b 65.0b 56.6a 1989b 95.1c 15.1a
Kcp1.25 5251a 81.6a 55.3b 2905a 114.1a 18.1a
Kcp1.00 4970a 80.2a 54.5b 2716a 113.5a 17.6a
Kcp0.75 3995b 71.2b 55.2b 2204b 109.8a 16.9a
Kcp0.50 3298c 63.9c 55.5b 1828c 99.0b 14.9b
significance levels. As compared with Kcp1.25 treatment,
about 17% irrigation water saving was achieved with Kcp1.00treatments. Therefore, it was recommended for
sun-flower irrigation with drip irrigation that irrigation interval could be selected as 10-day and Kcp coefficient could be taken as 1.00 provided that all the other soil-climate condi-tions and irrigation labor were also taken into consideration. In
this case, total irrigation water requirement of sunflower plants under Konya conditions was about 570 mm.
There is a continuous increase in vegetable oil needs of Turkey owing to increasing population and resultant con-sumptions. Present productions are not sufficient to meet cur-rent needs and deficit quantities are imported from abroad. Stable policies about the production of oil crops are also
Fig. 4 Yield response factor (ky) for individual growth years and average of 2 years Table 7 Correlation coefficients
I ET SY TW SOR SOY DM PH ST I 1.00 ET 0.99** 1.00 SY 0.98** 0.99** 1.00 TW 0.97** 0.99** 0.99** 1.00 SOR − 0.78** − 0.84** − 0.80** − 0.83** 1.00 SOY 0.99** 0.99** 0.99** 0.99** − 0.77** 1.00 DM − 0.77** − 0.76** − 0.80** − 0.79** 0.48 − 0.81** 1.00 PH 0.91** 0.96** 0.95** 0.97** − 0.89** 0.94** − 0.74** 1.00 ST 0.95** 0.98** 0.97** 0.98** − 0.87** 0.96** − 0.79** 0.98** 1.00 I irrigation, ET evapotranspiration, SY seed yield, TW thousand-seed weight, SOR seed oil ratio, SOY seed oil yield, DM dry matter, PH plant height, ST stalk thickness
**
insufficient in Turkey and such a case also negatively influ-ences sufficient use of currently available productions. Then, the country is experiencing an increasing deficit and depen-dency to foreign markets. Such deficits can only be met through increasing present production lands and practicing optimum treatments to get maximum yields from sunflower plants.
Acknowledgments This work was supported by the project of “13101014” by Selcuk University BAP office and is part of Nurcan Yavuz’s doctoral thesis.
References
Abdou SMM, El-Latif KA, Farrag RMF, Yousef KMR (2011) Response of sunflower yield and water relations to sowing dates and irrigation scheduling under middle Egypt condition. Adv Appl Sci Res 2:141– 150
Anonymous (2015)http://www.tuik.gov.tr/bitkiselapp/. Accessed 27 May 2017
Başalma D (1991) The effects of different sowing times on seed yield and yield components, protein ratio, oil ratio and variation of fatty acids in rape (Brassica napus ssp. Oleifera L.) and turnip rape (Brassica rapa ssp. Oleifera L.). phD. Thesis, Graduate School of Natural Sciences, Ankara Univ., Turkey, 127 pp (in Turkish, with English abstract)
Çetin Ö, Uygan D (2008) The effect of drip line spacing, irrigation re-gimes and planting geometries of tomato on yield, irrigation water use efficiency and net return. Agric Water Manag 95:949–958 Çetin Ö, Yıldırım O, Uygan D, Boyacı H (2002) Irrigation scheduling of
drip-irrigated tomatoes using Class A pan evaporation. Turk J Agric For 26:171–178
Demir AO, Göksoy AT, Büyükcangaz H, Turan ZM, Köksal ES (2006) Deficit irrigation of sunflower (Helianthus annuus L.) in a sub-humid climate. Irrig Sci 24:279–289
Doorenbos J, Kassam AH (1979) Yield response to water. FAO Irrigation and Drainage Paper, No:33, pp 193, Rome
Dorsan F, Sezgin F, Ul MA (1994) Investigation of water-yield functions in sunflower. Ege J Agric Res 31:25–32
English MJ, Raja SN (1996) Perspective of deficit irrigation. Agric Water Manag 32:1–14
Ertek A, Kanber R (2003) Effects of different drip irrigation programs on the boll number and shedding percentage and yield of cotton. Agric Water Manag 60:1–11
Ertek A,Şensoy S, Küçükyumuk C, Gedik I (2004) Irrigation frequency and amount affect yield components of summer squash (Cucurbita pepo L.). Agric. Water Manage 67:63–76
Fan Y, Wang C, Nan Z (2014) Comparative evaluation of crop water use efficiency, economic analysis and net household profit simulation in arid Northwest China. Agric Water Manag 146:335–345
Ghani A, Hussain M, Qureshi MS (2000) Effect of different irrigation regimes on the growth and yield of sunflower. Int J Agri Biol 2:334– 335
Howell TA, Cuence RH, Solomon KH (1990) Crop yield response. In: Hoffman GJ et al (eds) Management of farm irrigation systems. ASAE, St. Joseph, MI, p 312
Howell TA, Evett SR, Tolk JA, Copeland KS, Marek TH (2015) Evapotranspiration, water productivity and crop coefficients for
irrigated sunflower in the U.S. Southern High Plains. Agric Water Manag 162:33–46
James LG (1988) Principles of farm irrigation systems design, John Wiley and Sons. Inc., New York, s 543
Karam F, Lahoud R, Massaad R, Kabalan R, Breidi J, Chalita C, Rouphael Y (2007) Evapotranspiration, seed yield and water use efficiency of drip irrigated sunflower under full and deficit irrigation conditions. Agric Water Manag 90:213–223
Keller I, Bliesner RD (1990) Sprinkler and trickle irrigation, Chapman and Hall, 115 Fifth Avenue, New York, NY 10003
Kolsarıcı Ö (2004) The effects of irrigation applied at different growing periods on yield and yield components of sunflower (Helianthus annuus l.) under Ankara conditions. Ankara Univ. BAP, pp 104 Ankara.,Turkey
Lamm FR, Aiken RM, Aboukheira AA (2011) Irrigation research with sunflowers in Kansas, In: Proc. 23rd Annual Central Plains Irrig. Conf., Burlington, Colo., 22–23 February 2011, CPIA, Colby, Kan, pp. 169–180
Onat B, Arıoğlu H, Güllüoğlu L, Kurt C, Bakal H (2017) Oil seeds and crude oil production in the world and in Turkey. KSU J Nat Sci (Special issue) 20:149–153
Öztürk Ö, Akınerdem F, Bayraktar N, Ada R (2008) The investigation of yield and important agronomic characters of some hybrid sunflower cultivars under Konya irrigated conditions. Selcuk J Agric Food Sci 22:11–20
Seymen M, Yavuz D, Dursun A, Kurtar ES, Turkmen O (2019) Identification of drought-tolerant pumpkin (Cucurbita pepo L) ge-notypes associated with certain fruit characteristics, seed yield, and quality. Agric Water Manag 221:150–159
Sezen SM, Yazar A, Arıoğlu H, Şengül H, Konuşkan D, Eker S, Çolak YB, Günaçtı H, Atağ G, Kuşvuran K (2013) Determination of the effects of traditional and partial root drying (PRD) deficit irrigation strategies applied by drip method on sunflower yield and oil quality in Mediterranean climatic conditions. The Republic of Turkey Ministry of Food Agriculture, General Diroctorate of Agricultural Research and Policies, Project no TAGEMBB-090201C, final report 152 p, Turkey
Sezen SM, Yazar A, Eker S (2006) Effect of drip irrigation regimes on yield and quality of field grown bell pepper. Agric Water Manag 81: 115–131
Sezen SM, Yazar A, Kapur B, Tekin S (2011) Comparison of drip and sprinkler irrigation strategies on sunflower seed and oil yield and quality under Mediterranean conditions. Agric Water Manag 98: 1153–1161
Skoric D (1992) Achievements and future directions of sunflower breed-ing. Field Crops Res 30:231–270
Süllü A (2013) The evaluation of drip irrigation applications on second crop sunflower yield and quality in Söke region. Thesis, Adnan Menderes University Graduate School of Natural and Applied Sciences, Aydın, Turkey, M.Sc
Tanner CB, Sinclair TR (1983) Efficient water use in crop production: research or re-search? (Eds. H.M. Taylor et al.), Limitations to effi-cient water use in crop production, Amer. Soc. Apron. Inc. pp 1–27 Yavuz D, Seymen M, Yavuz N, Turkmen O (2015) Effects of irrigation interval and quality on the yield and quality of confectionary pump-kin grown under field conditions. Agric Water Manag 159:290–298 Yıldırım O (2003) Design of irrigation systems. Publication no 1536/489, in Turkish, Agriculture Faculty, Ankara University, 348 p, Ankara, Turkey
Yıldırım O, Korukçu A (1999) Drip irrigation systems design. Agriculture Faculty, Ankara University, pp 98–187, in Turkish, Ankara, Turkey
