ORIGINAL PAPER
Ramazan Acar1&Nur Koç1&Ade Sumiahadi1,2
Received: 7 January 2019 / Accepted: 31 October 2019 / Published online: 30 November 2019 # Saudi Society for Geosciences 2019
Abstract
Wild rocket (Diplotaxis tenuifolia (L.) DC.), a member of the Brassicaceae family, is vital in natural areas and soil protections as well as in human and animal nutrition. The study was conducted to determine the appropriate row spacing of Turkey’s native plant wild rocket in Konya conditions. This study was conducted in 2015; observations and measurements were carried out in the second (i.e., 2016) and third (i.e., 2017) years. In this study, fodder yield and its components consisted of plant height, canopy diameter, number of branches, fresh and dry fodder yield per plant, and dry fodder yield per hectare and seed yield and its components consisted of number of pods per branch, number of pods per plant, 1000 grains weight, seed yield per plant, and seed yield per hectare were examined. Macro and micronutrient contents of the plant were also analyzed in 2016. The results show that seed yield values such as seed yield (i.e., 76.2 kg ha−1) and 1000 grains weight (i.e., 1.00 g) were higher in 2016. However, in 2017, while seed yield was lower, plant height (i.e., 92.78 cm), canopy diameter (i.e., 85.67 cm), and fodder yield (i.e., 20339.5 kg ha−1) were higher. In nutrient contents (especially Ca, K, and Fe), 20- and 30-cm row spacings were determined as significant. Furthermore, the yield values related to dry fodder and seed yields are higher with 20- and 30-cm row spacings. This study indicated that 20- and 30-cm row spacings are recommended row spacing for wild rocket culture.
Keywords Fodder yield . Forage crop . Rangeland . Seed yield . Wild rocket (Diplotaxis tenuifolia)
Introduction
Wild rocket (Diplotaxis tenuifolia (L.) DC) is a member of the Brassicaceae family and found as a native to Turkey. There are five different species of Diplotaxis in Turkey. Diplotaxis tenuifolia is the only Diplotaxis species in Turkey that is pe-rennial with yellow flowers (Erik2012). Wild rocket is resis-tant to drought with the deep root system (Erik2012). This plant is also resistant to burn up and to cut, new shoots grow from the cut tops (Erik2012).
Wild rocket, which is the native plant of Turkey, has many different usage areas and potential usage areas. They are used as a secondary metabolites from the plant’s leaves in human nutrition; as a medicinal plant with active substances (Nicoletti et al.2007; Caruso et al.2018); as an oil plant with 35% oil content of the seed (Acar et al.2016); as a fodder plant due to being grazed by animals especially sheep (Özcan 2015); as fiprevention strips in pasture areas due to its re-sistance to fire (Erik2012); and as a water erosion prevention plant due to its perennial characteristic, rapid propagation, and high adaptability (Erik2012). The flowers have beautiful ap-pearance, and they can be a source of pollen for apiculture (honey production) when flowers are blooming in April– October (Tomas-Barberan et al.2009; Acar et al.2015). The seeds of this plant have the features that can be easily spread by sediment transportation that make this plant quickly cover the soil on the areas with sediment soil problem (Hurka et al. 2003; Erik2012; Caruso et al.2018).
Wild rocket is widely grown and traded in Italy and Spain (Erik2012; Hall et al.2012; Durazzo et al.2013; Kenigsbuch et al. 2014; Acar et al.2015). Despite the fact that there are many different areas that are using wild rocket, the farming and
Responsible Editor: Haroun Chenchouni * Nur Koç
nurkoc@selcuk.edu.tr
1
Department of Field Crops, Faculty of Agriculture, Selcuk University, Selcuklu, 42075 Konya, Turkey
2 Department of Agrotechnology, Agricultural Faculty, Universitas
Muhammadiyah Jakarta, Jl. K.H. Ahmad Dahlan, Cirendeu, Ciputat, Jakarta Selatan 15419, Indonesia
Investigation of yield, yield components and nutrient
contents of wild rocket (
Diplotaxis tenuifolia (L.) DC.)
trading of this plant have not been done in Turkey. Sufficient literature has not been found in this subject concerning seed or fodder productions especially in Konya conditions, although the recommended row spacing is 20 cm in vegetable production (Pimpini and Enzo1996; Caruso et al.2018). For this reason, this study was carried out to determine the appropriate row spacing of wild rocket in Konya conditions.
Materials and methods
Field work and experimental design
The study was conducted at the experimental field of Department of Field Crops, Selcuk University, Konya, Turkey; it started from May 6, 2015 and used randomized complete block design with three replications. The character-istics of experimental soil were as follows: it had a clayey-loam structure, high lime content (20 %), 18.3 kg ha−1of P2O5, 2.40% organic matter content in soil depth of 30 cm, an alkaline reaction (pH 8.12), and no salinity problems. Soil analysis results were shown in Table1, and climate character-istics are shown in Table2.
This experiment was carried out in 2015–2017. The plants were grown in three different row spacings (i.e., 20, 30, and 40 cm respectively). There was no fertilization during and after sowing. The sprinkler irrigation was done by 300 mm when the plant needed water on the July and August in 2016 and 2017.
Data collection
The plant germination occurred approximately 40 days after planting on June 13, 2015, and plant thinning was conducted when the plant had 4–5 leaves at 15 days later on June 26, 2015. In the first year, first flowering occurred 70 days after sowing. The first pods are harvested about 30 days after blossoming. The plant had a pod cracking feature and had no simultaneous maturation.
At the end of the first year, the cutting was done manually when the plants reached 10-cm height from the soil surface. The cuttings in the second (i.e., 2016) and third (i.e., 2017) years were also done with the same height (10 cm) from the same plants. In this study, to determine the feed value of wild rocket, the dry forage period was selected. There were no plants that can be grazed by the animals at that time, and the plant cutting time was preferred in the first week of October.
In the study, the observation was measured as cm via ruler at plant height and canopy diameter. In this research, the num-ber of primary branches, the numnum-ber of pods per branch, the number of pods per plant was calculated and dry fodder yield per plant (g), seed yield per plant (g), and 1000 grains weight (g) was weighed withanalytical balance. Dry fodder yield and Tabl
e 1 Soil characteristics of th e expe rimental field in K onya, T u rkey Nutr ien t ele m en ts V alue C at egor y Re fe re nce K (%) 0.03 V ery low (< 0 .005) Low (0.005 –0.01) Suf ficient (0.01 –0.02) High (0.02 –0 .09) V ery high (> 0.09) F A O 1 990 Mg (%) 0 .03 V ery low (< 0.005) Low (0.005 –0.016) Suf ficient (0.016 –0.048) High (0.048 –0.15) V ery high (> 0.15) F A O 1 990 Zn (ppm) 0 .91 V ery low (< 0.2) Insuf ficient (0.2 –0.5) Medium (0.5 –1.0) Suf ficient (1.0 –8.0) High (> 8.00) F A O 1 990 B (ppm) 3 .08 In suf ficient (< 0 .5) S uf ficient (0.5 –3) High (>8.00) W o lf 1971 Cu (ppm) 2 .07 In suf ficient (< 0 .2) M edium (0.2 –0.25) Suf ficient (0.25 –1) High (>1.00) Follet 1969 F e (p pm ) 1 .1 9 Ins u ff ic ien t (< 2 .5 ) M ed iu m (2 .5 –4.5) Suf ficient (> 4.5) Lindsay an d N orvell 1969
seed yield per hectare were determined by calculation. The nutrient content of plant samples from the second year cutting (i.e., 2016) was established by the following method. Method: After being dried with the oven in temperature of 70oC, 0.2-mg leaf sample was put into the tube. A total of 5 ml of HNO3and 2 ml of H2O2were added into each tube. The sample was crushed in the microwave oven (MARSX Press Microwave) then immediately transferred into 50-ml plastic tube and filled with 20 ml of distilled water. Then, each solution of the sample was filtered, transferred into the tube, and analyzed using ICP-AES (Varian-Vista Model, axial) (USDA2004).
Data analysis
The values related to the yield were analyzed according to the experimental design of split plot in randomized block design, while the values related to the nutrients were analyzed according to randomized complete block
design, and the Least Significant Differences (LSD) test was performed for each significant amount. The statisti-cal analysis of all variables was performed using MSTAT-C program.
Result and discussion
Fodder yield and its components
Table3shows the averages of fodder yield and related com-ponents of wild rocket. The result of variance analysis shows that the values of years are significant, and the highest fodder yield and its components were obtained from the values of the year 2017.
The capital letters show the significance in LSD at 1% significance level; The small letters show the significance in LSD at 5% significance level
In this study, dry fodder yield per plant and fodder yield per hectare were significant at 1%. The highest plant height was recorded as 95.55 cm in the year 2017 with 30-cm row spacing. In average, this value is higher than the reported results from Yaniv (1995) and Tripodi et al. (2017) that the plant height of wild rocket was 80 cm, and de Feo and Senatore (1993) stated that this plant can grow up to 70-cm tall.
The highest canopy diameter (92.22 cm) was obtain-ed in the year 2017 with 30-cm row spacing. Erik (2012) indicated that the plant could occupy up to 1-m2 area (approx. 115 cm). The maximum number of branches per plant was obtained in 30- and 40-cm row
Table 2 Climate characteristics of the experimental field in Konya, Turkey
Year Monthly average
relative humidity(%) Monthly average temperature (°C) Annual total precipitation (mm) 1980–2014 55.60 12.60 348.23 2015 59.10 11.50 375.60 2016 51.23 12.54 290.20 2017 59.44 11.43 314.10
Table 3 The means and standard error belonging to fodder yield and its components of wild rocket cultivated in different row spacings Year of cutting Row spacing (cm) Plant height (cm) Canopy diameter (cm) Number of branches Dry fodder yield
per plant (g plant−1)
Fodder yield (kg ha−1) 2016 20 60.17 ± 5.63 53.50 ± 6.43 11.11 ± 2.07 11.85d± 3.32 3805.0d± 734 30 60.78 ± 5.63 67.89 ± 6.43 15.84 ± 2.07 21.32d± 3.32 3897.8d± 734 40 59.28 ± 5.63 68.00 ± 6.43 15.89 ± 2.07 20.14d± 3.32 3714.2d± 734 Average 60.07B± 3.25 63.13B± 3.71 14.28B ±1.20 17.77B± 1.92 3805.6B± 423 2017 20 87.33 ± 5.63 75.33 ± 6.43 16.00 ± 2.07 55.00c± 3.32 18,333.4b± 734 30 95.55 ± 5.63 92.22 ± 6.43 22.11 ± 2.07 133.33a± 3.32 29,629.6a± 734 40 95.44 ± 5.63 89.44 ± 6.43 27.83 ± 2.07 78.34b± 3.32 13,055.6c± 734 Average 92.78A± 3.25 85.67A± 3.71 21.98A± 1.20 88.89A± 1.92 20,339.5A± 423 Averages 20 73.75 ± 3.98 64.42 ± 4.55 13.56b± 1.47 33.42b± 2.35 11,069.2b± 519 30 78.17 ± 3.98 80.06 ± 4.55 18.97a± 1.47 77.33a± 2.35 16,763.7a± 519 40 77.36 ± 3.98 78.72 ± 4.55 21.86a± 1.47 49.24b± 2.35 8384.9b± 519 General average 76.43 ± 4.46 74.40 ± 3.91 18.13 ± 1.49 53.33 ± 10.39 12,072.6 ± 2342 LSDrow spacing - - 4.83 17.990 3633.00
LSDrow spacing x year - - - 15.140 3797.00
spacing. Nicoletti et al. (2007) stated that it is compli-cated to make an exact measurement on the yield of wild rocket. However, according to Raimo and Miccio (unpublished), referred by Nicoletti et al. (2007), the wild rocket can produce 27,000-kg ha−1 yield. In this study, the fodder yield per plant (133.33 g) and fodder yield per hectare (29629.6 kg ha-1) obtained from 30-cm row spacing in the year 2017 (Fig. 1) are similar to the findings of other researchers.
Seed yield and its components
The averages of the seed yield and its components of the wild rocket are shown in Table 4. As a result of the variance analysis, the values of years were significant
and the highest seed yield and its components were obtained from the year 2016. In this study, seed yield per plant and seed yield per hectare were significant at 1%, while 1000 grains weight was at 5%.
The capital letters show the significance in LSD at 1% significance level. The small letters show the significance in LSD at 5% significance level
The highest number of pods per branch and number of pods per plant in the year 2016 were obtained from 30- and 40-cm row spacing. The highest 1000 grains weight was obtained from the row spacing of 30 cm (1.19 g). This result is higher than the results of Bianco (1995) (i.e., 0.18–0.20 g) and Török et al. (2013) (i.e., 0.295 g). The highest seed yield per plant was obtained in the year 2016 with 40-cm row spacing 0 500 1000 1500 2000 2500 3000 20 cm 30 cm 40 cm a d g k( dl ei y re d d of yr D -1) Row spacing 2016 2017 Avr. 0 2 4 6 8 10 20 cm 30 cm 40 cm Seed yield (k g da -1) Row spacing 2016 2017 Avr.
Fig. 1. Dry fodder yield (left) and seed yield (right) of wild rocket cultivated in different row spac-ings (2016 and 2017)
Table 4 The means and standard error belonging to seed yield and its components of wild rocket cultivated in different row spacings Year of cutting Row spacing (cm) Number of pods
per branch
Number of pods per plant
1000 gains weight (g) Seed yield per plant (g plant−1) Seed yield (kg ha−1) 2016 20 86.67 ± 4.53 960.78 ± 93.83 0.84b± 0.05 0.24c± 0.005 93.1 ± 13.98 30 89.42 ± 4.53 1425.58 ± 93.83 1.19a± 0.05 0.45b± 0.005 83.3 ± 13.98 40 89.34 ± 4.53 1414.75 ± 93.83 0.96ab± 0.05 0.49a± 0.005 52.1 ± 13.98 Average 88.47A± 2.61 1267.036A± 54.17 1.00A± 0.03 0.39A± 0.003 76.2A± 8.07 2017 20 20.00 ± 4.53 317.78 ± 93.83 0.37c± 0.05 0.12f± 0.005 41.2 ± 13.98 30 28.50 ± 4.53 627.22 ± 93.83 0.11d± 0.05 0.22d± 0.005 33.9 ± 13.98 40 42.83 ± 4.53 1130.83 ± 93.83 0.22cd± 0.05 0.15e± 0.005 28.9 ± 13.98 Average 30.44B± 2.61 691.944B± 54.17 0.23B± 0.03 0.17B± 0.003 34.7B± 8.07 Averages 20 53.33b± 3.20 639.28b± 66.35 0.60 ± 0.04 0.18c± 0.004 67.1 ± 9.88 30 58.96ab± 3.20 1026.40a± 66.35 0.65 ± 0.04 0.34a± 0.004 58.6 ± 9.88 40 66.08a± 3.20 1272.79a± 66.35 0.59 ± 0.04 0.32b± 0.004 40.5 ± 9.88 General average 59.46 ± 7.39 979.49 ± 103.38 0.62 ± 0.09 0.28 ± 0.04 55.4 ± 7.62 LSDrow spacing 9.997 383.200 - 0.003
-LSDrow spacing x year - - 0.245 0.003
(0.49 g plant−1). The highest seed yield was taken from the year 2016 with 20-cm row spacing (93.1 kg ha−1) (Fig. 1). These differences may be caused by the plant variety, soil and method used, and climate factors. In this study, seed yield and its components were higher in the year 2016. In 2017, the values of seed yield and its components were lower than in 2016, and decreasing of bee activity may be the cause to this situation.
Nutrient contents
Table5 shows the averages of the macronutrient contents of wild rocket. The results show that Ca and K contents were significant at 1%, while other macronutrients were not signifi-cant. Table5also shows that the highest macronutrient contents were observed in 20-cm row spacing. Values related to micro-nutrient contents are given in Table6. While B content was significant at 5%, all other microelements were significant at 1%, except Na content. Table6also shows that Cu, Mn, Zn,
and Pb contents were higher in 20-cm row spacing, while Co, Cr, Mo, and Ni contents were higher in 30-cm row spacing.
According to the reports from Pimpini et al. (2005), referred by Nicoletti et al. (2007), the leaves are rich in nutrients with 0.47% K, 0.31% Ca, and 52-ppm Fe. However, the results obtained in our study contain a higher proportion of nutrients than the results from both Pimpini et al. (2005) and Bozokalfa et al. (2009). These differences can be caused by the fact that the other two researchers have done mineral analysis on the leaves and that this study analyzed the mineral contents from all parts of the plant (leaves, stems, pods, and seeds).
Grabner et al. (2011) reported the potential of the wild rocket as a bio-monitor in the soil with heavy metal pollution. The wild rocket that grows in the areas with and without pollution has Pb content of the aboveground parts as 0.68 and 12.36 ppm, respectively, and Zn content as 37.80 and 151.60 ppm, respec-tively. According to Grabner et al. (2011), who specified 30 ppm as Pb limit value for animal feed, the results of this study were below this limit in all row spacings used.
Table 5 The means and standard error belonging to macronutrient contents of wild rocket cultivated in different row spacings
Macronutrient (%) Row spacing (cm) Average LSD value Coefficient of
variation (%) 20 30 40 Ca 2.22a± 0.36 1.75b± 0.36 1.73c± 0.36 1.90 ± 0.21 0.004 0.31** K 1.77a± 0.04 1.38b± 0.04 1.61ab± 0.04 1.59 ± 0.06 0.251 4.83** Mg 0.39 ± 0.02 0.39 ± 0.02 0.36 ± 0.02 0.38 ± 0.01 - 10.27 P 0.16 ± 0.01 0.14 ± 0.01 0.15 ± 0.01 0.15 ± 0.005 - 10.44 S 0.72 ± 0.03 0.62 ± 0.03 0.71 ± 0.03 0.69 ± 0.02 - 7.50
The capital letters show the significance in LSD at 1% significance level. The small letters show the significance in LSD at 5% significance level **P < 0.01; *P < 0.05
Table 6 The means and standard error belonging to micronutrient contents of wild rocket cultivated in different row spacings
Micronutrient (ppm) Row spacing (cm) Average LSD value Coefficient of
variation (%) 20 30 40 B 30.08a± 1.01 26.74ab± 1.01 24.26b± 1.01 27.03 ± 1.01 4.211 6.87* Co 0.47b± 0.002 0.56a± 0.002 0.001c± 0.002 0.34 ± 0.08 0.004 0.29** Cr 1.01b± 0.04 1.38a± 0.04 1.06b± 0.04 1.15 ± 0.05 0.266 6.27** Cu 9.80a± 0.26 8.41b± 0.26 7.34b± 0.26 8.51 ± 0.37 1.313 4.10** Fe 451.35a± 2.38 432.13a± 2.38 349.65b± 2.38 411.04 ± 15.48 21.590 1.40** Mn 38.31 ± 4.44 39.19 ± 4.44 34.11 ± 4.44 37.20 ± 2.36 - 18.99 Mo 0.15c± 0.008 0.96a± 0.008 0.36b± 0.008 0.49 ± 0.12 0.004 3.87** Na 1584 ± 431 2372.67 ± 431 2166.43 ± 431 2040 ± 245 - 26.96NS Ni 0.85c± 0.006 1.19a± 0.006 1.10b± 0.006 1.05 ± 0.05 0.004 0.53** Pb 9.68a± 0.79 8.56b± 0.79 5.04c± 0.79 7.76 ± 0.50 0.004 0.02** Zn 21.44a± 0.39 13.68b± 0.39 13.676b± 0.39 16.27 ± 1.31 3.005 4.91**
The capital letters show the significance in LSD at 1% significance level. The small letters show the significance in LSD at 5% significance level. **P < 0.01; *P < 0.05
Conclusion
In this study, it can be stated that wild rocket is more produc-tive in 20- and 30-cm row spacings, considering the fodder and seed yields and high nutrient contents of wild rocket. According to this research, the 20- and 30-cm row spacings were found to be the recommended row spacing for wild rocket culture. However, it is recommended to use the appro-priate row spacing depending on production purposes (fodder, seeds, or high-nutrient vegetable production). In addition to these studies, advanced studies should be carried out on plant density and fertilization.
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