Response of Euryops Pectinatus L. Plants to Different Types of Fertilizers and Growth Retardants

Middle East Journal of Applied Volume : 08 | Issue :02 |April-June| 2018 Sciences Pages: 492-507 ISSN 2077-4613

Response of Euryops pectinatus L. Plants to Different Types of Fertilizers and Growth Retardants

1Ashour H.A., 1Heider S. M. and 2Abdel Wahab M. Mahmoud

1Department of Ornamental Horticulture, Faculty of Agriculture, Cairo University, Giza, Egypt. 2Department of Plant Physiology, Faculty of Agriculture, Cairo University, Giza, Egypt. Received: 26 Feb. 2018 / Accepted: 30 April 2018/ Publication date: 14 May 2018

ABSTRACT

This research was carried out at the experimental nursery of the Ornamental Horticulture Department, Faculty of Agriculture, Cairo University, during two successive seasons of 2016 and 2017. The aim of present study was to evaluate the effect of two different types of fertilizers, growth retardants and their interaction on vegetative growth, flowering, chemical constituents and anatomical structure of Euryops pectinatus plants. The plants were fertilized with either conventional NPK fertilizer or with Osmocote as slow release fertilizer, in addition to unfertilized plants were used as a control. Simultaneously the plants were foliar sprayed monthly with either paclobutrazol (PAC) 50 and 100 ppm or Cycocel (CCC) 1000 and 1500 ppm, in addition to the control plants sprayed with tap water. The results showed that fertilization treatments significantly increased most vegetative growth parameters (plant height, number of branches/plant, stem diameter, plant width, show value, fresh and dry weights of shoots, root length as well as fresh and dry weights of roots), flowering characteristics (flowers number/plant, flowers diameter and flowers fresh and dry weights) as well as chemical constituents including the contents of total chlorophylls, total carbohydrates, N, P, K, Fe, Mn, Zn, total indoles and total phenols compared to unfertilized control plants. It was clear that, slow release fertilizer was significantly superior to conventional NPK fertilizer. In most cases, spraying plants with growth retardants treatments PAC or CCC significantly reduced some morphological traits but caused significant increase in number of branches/plant, stem diameter, plant width and show value as compared to control plants. Spraying with two concentrations of PAC or CCC significantly increased the contents of total chlorophylls, total carbohydrates, N, P, K, Fe, Mn, Zn and total phenols while reduced total indoles content as compared to control.

Key words: Euryops pectinatus, NPK, slow release fertilizer, paclobutrazol, cycocel.

Introduction

Euryops pectinatus L. is a species of flowering plants belongs to the family of Asteraceae, native to South Africa. It is a vigorous evergreen shrub and commonly known as golden daisy bush. The plant grows to1 m tall and wide, the leaves are 4-10 cm long, pinnate, narrow, divided, hairy, soft and grey- green in color. The flowers are attractive, reaching 5 cm in diameter, yellow, daisy-like composite flowers and the flowering season generally runs from early summer through to autumn and into winter in mild areas. The plant widely used as ornamental plant, especially in urban areas owing to its bright yellow flower, perpetual flowering regime and fern-like leaves. It grows best in full sun and well- drained soils. It must be grown in a protected place, away from frost-prone areas. There is a cultivar called Euryops pectinatus 'Viridis' (Green Golden Shrub Daisy) that looks the same but the leaves are a dark green in color. (Odenwald, and Turner, 2006). The suitable fertilization is one of the pivotal factors affecting the growth and flowering plants cultivated in pots (Kozik et al., 2004). Using a commercial soluble fertilizers is a conventional practices used in the production of ornamental plants. Although, this practice are relatively easy by providing the plants with adequate amounts of needed nutrients to ensure their growth, however, it is considered prodigal and cause nutrients losses by leaching with low nutrients use efficiency. Recently, with the high cost of fertilizers, using effective alternative tools to enhance the nutrients use efficiency and reduce nutrient losses are strongly needed (Krug et al., 2014). Slow-release fertilizers are described as

Corresponding Author: Ashour, H. A., Ornamental Horticulture Department, Faculty of Agriculture, Cairo University, Giza, Egypt. E-mail: [email protected] 492 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613 materials that slowly release nutrients over an extended period of time. These fertilizers represent an excellent alternative to use of fast-acting fertilizers as they are safer to handle, reduce labor cost, enhance nutrients use efficiency, avoid the injury of high salt level in the potting media and minimize leaching of nutrients, moreover they offers valuable, cheaper and simple way to supply nutrients particularly for the nurseries with the low technology (Shaviv, 2001 and Oliet et al., 2004). Also, at high rates of application, the fertilizer burn is not a problem with these fertilizers (Yuan-liang et al., 2009). It has been reported that application of slow-release fertilizers has a better impact on improving growth and flowering traits of different ornamental plants including Coreopsis grandiflora (Kozik et al., 2004), Clematis cultivars (Bosiacki, 2008), Dendranthema grandiflora (Yahya et al., 1999; Zhu et al., 2009; Kaplan et al., 2013 and Asrar et al. 2014) and Lavandula angustifolia (Matysiak, and Nogowska, 2016). Other advantages of these fertilizers are increasing the contents of chlorophyll and causing a higher uptake of N, P or K nutrients by plants (Abou-Taleb and Hassan 1995; Song et al., 2011 and Oliet et al., 2004). In addition such fertilizers have been reported to lower leaching of nutrients as compared to those soluble fertilizers (Andiru, 2010). Furthermore, it has been found that, slow - release NPK fertilizer was more effective on enhancing vegetative growth parameters, increasing the contents of total chlorophylls, total carbohydrates, N, P and K percentage in leaves when compared to conventional NPK fertilizer (Hussein (2009). Growth retardants (GRs) are synthetic chemicals substances used as effective practice for controlling plant height and produce aesthetic compact pot plants (Chany, 2005). GRs used to inhibit cell division and cell elongation in the tissues of shoot and regulate plant height without obvious phytotoxicity effects (Pgrsa, 2007). Examples of such GRs are paclobutrazol and cycocel that are widely used in controlling growth of ornamental plants. Paclobutrazol (PAC) acts by blocking the enzyme entkaurene oxidase that converts ent-kaurene to ent-kaurenoic acid in the gibberellins biosynthetic pathway (Rademacher, 2000). PAC application at concentration ranged from 10-500 ppm has been reported on reducing plant growth of various ornamental plants expressed as plant height and fresh and dry weight of plant organs, increasing number of branches, stem diameter and show value (Ghatas 2016, Sharaf-Eldien et al., 2017), increasing the flower parameters (Singh and Bist, 2003; Rathore et al. 2011and Asgarian et al., 2013), increasing the contents of pigments and total carbohydrates (El-Quesni et al., 2007), as well as increasing N, P and K% in pant organs (Youssef et al. 2013 ). Moreover, resent studies have been reported that foliar application of PAC at 20 - 60 ppm increased cytokinins, salicylic acid and total phenols, while decreased gibberellins and auxins contents (Ghatas 2016 and Abd El-Aal and Mohamed, 2017). Cycocel (CCC) is one of the synthetic chemical utilized to retard plant growth either by retarding translocation of gibberellins or by enhancing their degradation (Biswas et al., 2018). It is also used on ornamental plants in order to produce compact foliage and flowering potted plants, promote the green color of the foliage, sturdy flower stem and enhance plant resistance environmental stresses. CCC effect on plants can differ according to its concentration, application method, species and growing season (Taiz and Zeiger, 2006). Foliar application of CCC at concentration ranged from 250-1000 ppm decreased plant height, increased the fresh and dry weight of leaves and increased the number of branches, leaves and inflorescences of Pelargonium zonale (Ibrahim and Hassanian, 2001). The concentration of 4000 ppm increased stem diameter, number of branches and number of leave and resulted in maximum flower diameter, shelf-life and flowers number of Dahlia variabilis (Khan and Tewari. 2003). The concentration of 500-1500 ppm CCC reduced plant height, fresh and dry weight of plant organs compared to control. (Bhat et al., 2011 and Gholampour et al., 2015). On Tagetes erecta, CCC foliar sprayed at 1000-2000 ppm reduced plant height and the higher number of branches, leaves, spread and flower yield were scored with CCC at 2000 ppm (Khan et al., 2012). on Tabernaemontana coronaria, foliar application of CCC at 1000-2000 ppm, decreased plant height and leaf area, while caused increase in number of branches, number leaves / plant, number of flowers/plant, flowers fresh and dry weights of leaves, show value and chemical constituents such as total chlorophylls, total carbohydrates, and leaf N, P, K, in addition to increase in cytokinins content and reduction in content the contents of gibberellins and auxins (Youssef et al., 2013). Similar findings have been obtained on Chrysanthemum frutescens by foliar spraying of CCC at 1000-3000 ppm (Ghatas, 2016). Although, the effect of NPK fertilization or growth retardants have been studied on different ornamental flowering plants. However, there is no available data about their efficiency on the performance and production of Euryops pectinatus as pot plant. Thence, the main object of this work

493 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613 was to study the effects different types of NPK fertilization, growth retardants and their interactions on vegetative growth, flowering, chemical constituents and anatomical structure of potted Euryops pectinatus plants. Taking into consideration that according to our knowledge, this is the first paper investigate the impact of fertilization in combined with growth retardants on Euryops pectinatus plants.

Materials and Methods

This experiment was conducted at the Nursery of Ornamental Horticulture Department, Faculty of Agriculture, Cairo University, Giza, Egypt during the two successive seasons of 2016 and 2017. The aim of this work was to investigate the effect of two different types of fertilization, two growth retardants and their interactions on vegetative growth, flowering, chemical constituents and anatomical structure of Euryops pectinatus plants.

Experimental procedures

On 1st of February, Uniform seedlings of Euryops pectinatus having 4-6 branches and 18-20 cm height were obtained from a commercial nursery and repotted in 30 cm diameter plastic pots (one seedling /pot) filled a mixture of 2 clay: 1 sand: 1 peat moss (v: v: v), and the pots were placed in sunny area until the end of the experiment. Some chemical properties of soil mixture used in the experiment were carried out as described by Estefan et al. (2013) and presented in Table 1.

Table 1: The chemical analysis of soil mixture used for growing Euryops pectinatus during 2016 and 2017 seasons.

EC Organic pH CaCO3 Available Macro-elements Seasons (dS/m) matter (%) (%) (ppm) Nitrogen Phosphorus Potassium 2016 0.99 2.25 6.77 1.46 5422 674 917 2017 1.23 1.93 6.44 1.34 5166 685 887

Starting from 1st March till 1st October in both seasons, the plants were fertilized with a conventional NPK fertilizer as a soluble fertilizer or Osmocote as slow release fertilizer (18 N - 6 P2O5 -12 K2O, 3-4 month release period). The conventional NPK fertilizer was prepared by mixing 195.65 g urea (46% N), 193.55 g calcium superphosphate (15.5% P2O5) , 125.00 g potassium sulphate (48% K2O) and 485.80 g sand as an inert component, giving 1 kg of NPK mixture (with a formula of 9-3-6, and a ratio of 3:1:2). The fertilizer mixture was applied immediately after preparation by incorporating into the soil 2 cm depth at rates of 10 or 14 g/pot/month. Osmocote (obtained from Egyptian Group for Development Giza, Egypt) was applied two times as a top dressing at the rate of 20 or 28 g/ pot every 4 month, in addition to unfertilized plants were used as a control. The rates of conventional NPK fertilizer provided the same amount of elements provided by the rates of slow release fertilizer. In both seasons, the plants received the different fertilization treatments were foliar sprayed monthly with either paclobutrazol [PAC, (2RS,3RS) -1-(4-chlorophenyl-4,4 -dimethyl-2-(1H-1,2,4 triazol-1- yl) pentan-3-ol, obtained from Tecknogreen company, Egypt ] at a concentrations of 50 and 100 ppm or Cycocel [CCC, chlormequat; 2-chloroethyltrimethyl ammonium chloride, obtained from Hydro Agri Trade Egypt Company] at a concentrations of 1000 and 1500 ppm, in addition to the control plants sprayed with tap water. Foliar application of each growth retardants treatment was foliar sprayed in early morning using hand pump mister after adding Bio-new film at 1 ml /L as wetting agent and the foliage of plants were sprayed to reach the point of runoff (90 ml / plant). The common agricultural practices such as regular irrigation, hand picking of weeds, insect and disease control were also performed.

Experimental design

The experiment was designed in randomized complete block design with 25 treatments [5 fertilization rates (including the control) X 5 growth retardants (including the control)] each treatment

494 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613

consisting of 9 pots which randomly arranged in three replicates with 3 pots /replicate (each replicate consisting of 75 pots). Data recorded

On 30th October in two seasons, the experiment was terminated and the vegetative growth parameters were recorded, including plant height (cm, measured from soil surface to the tallest branch), number of branches/plant, stem diameter (mm, at 5 cm above soil surface), plant width (cm), show value (as plant width/plant height ratio according to Berghage et al. (1989), fresh and dry weights of shoots (leaves+ stems) root length (cm), as well as fresh and dry weights of roots/plant. Flowering parameters including number of flowers /plant, diameter of flowers(cm) as well as fresh and dry weights of flowers (g/ plant) were also recorded four times during flowering season and the average of data were recorded. Additionally, determinations of chemical composition including total chlorophylls in fresh leaf samples were determined by using chlorophyll meter Model SPAD 502 according to Netto et al. (2005), total carbohydrates content (% of dry matter) was determined in dried shoots samples according to the methods recommended by Dubois et al. (1956). Dried shoots samples were digested to extract nutrients (Piper, 1947) and the extract was chemically analyzed to determine its contents of N, P and K content using the procedure described by Cottenie et al. (1982). The contents of, Fe, Mn and Zn (ppm) were estimated according to Lindsay and Norvell (1978).Also, total indoles and total phenols (mg/100g fresh matter) were determined in fresh leaves according to A.O.A.C. (1990).

Anatomical study

Leaf samples were taken from the 5th leaf from top of plants at the end of 2017 season. The specimens were taken and fixed for at least 48 hours in F.A.A. solution (5ml. formalin, 5ml. glacial acetic acid and 90 ml. ethyl alchohol 70%), washed in 50 % ethyl alcohol, dehydrated in a series of ethyl alcohols (70, 90, 95 and 100%), infiltrated in xylene, embedded in paraffin wax of a melting point 60-63 0C (Sass,1950), sectioned to 20 microns in thickness using a rotary microtome, double stained with fast green and safranin, cleared in xylene and mounted in Canada balsam (Johnason, 1940). Sections were microscopically examined using a micrometer eye piece read to detect histological manifestation of noticeable responses resulted from the treatments.

Statistical analysis

All obtained data during both seasons of study were subjected to analysis of variance (ANOVA) as a factorial experiment in randomized complete block design, according to Steel et al. (1997), The differences between the mean values of various treatments were compared by using the "Least Significant Difference (LSD)" test at 5% level.

Results and Discussion

A. Vegetative growth parameters

The data recoded during two seasons' (Tables 2 and3) revealed that, fertilization treatments had a noticeable effect on the vegetative growth parameters of Euryops pectinatus plants. In both seasons, plant height, number of branches/plant, stem diameter, plant width, show value, fresh and dry weights of shoots, root length as well as fresh and dry weights of roots were increased significantly due to addition of both two fertilizers types (conventional NPK or Osmocote as slow release fertilizer) compared to unfertilized control plants. The only exceptions to the obtained trend were recorded with conventional NPK at low rate (10 g/plant/month) which caused insignificant increase in with show value in both seasons as well as dry weights of shoots and roots in the first seasons. The data in Tables (2 and 3) also showed that, raising application rate of the two chemical fertilizers caused steady increments in most studied parameters. However the slow -release NPK fertilizer (Osmocote) was superior in its significant effect to conventional NPK fertilizer. Among the two rates of Osmocote, the higher one (28 g/plant/ 4month) was the most effective treatment which gave the highest values of growth attributes. The increase in vegetative growth parameters owing to chemical NPK treatments are

495 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613 in agreement with the finding of previous studies (Habib, 2012, Youssef, 2014 and El-Naggar et al. 2016), while such increases in the recorded values by addition of slow -release NPK fertilizer are in conformity with that recorded by prior researches in some ornamental plants (Kozik et al., 2004; Yahya et al., 1999; Schroeter-Zakrzewska and Kleiber, 2012; Kaplan et al., 2013, Asrar et al., 2014 and Matysiak and Nogowska, 2016). Moreover the superior effect of slow -release NPK fertilizer on vegetative growth parameters when compared to conventional NPK fertilizers is coincided with those obtained by Hussein (2009).

Table 2: Effect of fertilization, growth retardants treatments and their interactions on plant height, number of branches/plant, stem diameter, plant width and show value of Euryops pectinatus during the 2016 and 2017 seasons. Stem Show value Plant height Number of diameter Plant width (plant Fertilization (F) *GR,(ppm) (cm) branches/plant (mm) (cm) width/height ratio) 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 0 38.12 36.32 17.33 16.56 9.56 9.99 19.61 18.72 0.51 0.52 Control PAC (1) 29.60 30.30 18.67 17.67 10.79 11.00 21.20 19.55 0.72 0.65 PAC (2) 26.95 27.81 19.56 18.11 11.41 11.85 24.46 23.83 0.91 0.86 CCC (1) 33.12 34.49 17.41 16.56 9.98 10.91 20.14 19.87 0.61 0.58 CCC (2) 29.88 33.02 18.11 16.78 10.51 10.83 21.88 22.50 0.73 0.68 Mean 31.53 32.39 18.22 17.13 10.45 10.91 21.46 20.89 0.70 0.66 0 40.98 42.37 17.89 19.22 10.46 11.78 23.63 24.92 0.58 0.59 Conventional PAC (1) 33.59 32.44 21.66 20.78 12.03 13.70 28.55 30.68 0.85 0.95 NPK (10 PAC (2) 29.76 31.11 22.00 20.89 12.47 13.78 31.11 32.26 1.05 1.04 g/plant/month) CCC (1) 35.19 37.89 19.54 17.89 11.40 12.04 21.63 23.42 0.61 0.62 CCC (2) 34.38 34.97 21.33 19.78 11.77 13.26 23.93 27.13 0.70 0.78 Mean 34.78 35.75 20.49 19.71 11.63 12.91 25.77 27.68 0.76 0.79 0 42.76 44.33 18.56 19.56 11.79 11.91 26.73 27.53 0.63 0.62 Conventional PAC (1) 33.05 30.98 23.11 21.56 13.66 14.50 32.11 34.92 0.97 1.13 NPK PAC (2) 31.12 35.14 23.22 21.78 14.25 14.41 34.10 36.05 1.10 1.03 (14 CCC (1) 40.62 38.40 21.00 19.56 13.33 13.48 28.23 32.30 0.70 0.84 g/plant/month) CCC (2) 43.38 38.39 21.67 20.11 13.08 13.34 30.32 32.01 0.70 0.83 Mean 38.19 37.45 21.51 20.51 13.22 13.53 30.30 32.56 0.82 0.89 0 43.75 45.81 19.00 20.56 11.98 12.68 28.70 28.14 0.66 0.61 Slow release PAC (1) 36.79 35.52 21.33 24.78 12.54 13.65 29.48 31.67 0.80 0.89 NPK PAC (2) 35.60 35.98 24.33 23.44 15.11 14.49 41.48 39.60 1.17 1.10 (20 g/plant/4 CCC (1) 39.96 41.17 22.22 25.89 14.21 13.22 34.08 31.71 0.85 0.77 month) CCC (2) 37.89 39.91 22.11 25.22 13.62 12.45 32.47 33.79 0.86 0.85

Mean 38.80 39.68 21.80 23.98 13.49 13.30 33.24 32.98 0.87 0.84 0 48.45 47.45 22.22 21.11 13.05 12.72 28.24 31.48 0.58 0.66 Slow release PAC (1) 42.96 44.14 23.89 25.89 14.97 12.68 41.41 44.41 0.96 1.01 NPK PAC (2) 40.45 41.85 24.33 26.11 15.88 14.67 47.85 48.54 1.18 1.16 (28 g/plant/4 CCC (1) 46.14 42.09 23.22 25.44 14.97 13.90 39.05 40.35 0.85 0.96 month) CCC (2) 40.21 41.69 23.89 24.89 15.52 14.02 40.80 42.39 1.01 1.02

Mean 43.64 43.44 23.51 24.69 14.88 13.60 39.47 41.43 0.92 0.96 0 42.81 43.26 19.00 19.40 11.37 11.82 25.38 26.16 0.59 0.60 Mean of GR PAC (1) 35.20 34.68 21.73 22.13 12.80 13.11 30.55 32.25 0.86 0.92 PAC (2) 32.78 34.38 22.69 22.07 13.82 13.84 35.80 36.06 1.08 1.04 CCC (1) 39.00 38.81 20.68 21.07 12.78 12.71 28.62 29.53 0.72 0.75 CCC (2) 37.15 37.59 21.42 21.36 12.90 12.78 29.88 31.56 0.80 0.83 L.S.D. (0.05) Fertilization (F) 3.02 3.08 1.66 1.45 1.17 0.99 3.01 3.13 0.12 0.15 Growth retardants (GR) 3.02 3.08 1.66 1.45 1.17 0.99 3.01 3.13 0.12 0.15 FX GR 6.74 6.89 3.71 3.25 2.61 2.21 6.74 7.00 0.26 0.34 *PAC= paclobutrazol PAC (1) = 50 ppm PAC (2) = 100 ppm CCC = cycocel CCC (1) = 1000 ppm CCC (2) = 1500 ppm

496 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613

Table 3: Effect of fertilization, growth retardants treatments and their interactions on shoots fresh and dry weights, root length as well as roots fresh and dry weights of Euryops pectinatus during the 2016 and 2017 seasons. Shoots fresh Shoots dry Root length Roots fresh Roots dry weight (g/plant) weight (cm) weight weight Fertilization (F) *GR,(ppm) (g/plant) (g/plant) (g/plant) 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 0 60.26 69.65 20.71 19.95 19.37 19.18 23.60 21.10 14.22 9.95 Control PAC (1) 45.24 43.91 20.88 17.84 19.47 19.80 18.34 18.15 12.65 8.47 PAC (2) 42.89 41.38 18.71 16.71 15.35 16.71 19.67 19.01 9.68 8.41 CCC (1) 42.38 38.53 17.44 16.61 15.07 16.07 16.69 17.55 9.47 8.26 CCC (2) 46.22 41.05 19.37 16.75 15.68 16.45 17.67 19.01 10.01 8.54 Mean 47.40 46.90 19.42 17.57 16.99 17.64 19.19 18.97 11.21 8.72 0 119.61 128.02 24.86 33.15 24.62 27.05 43.29 37.42 14.43 18.53 Conventional PAC (1) 102.77 65.85 20.07 22.31 19.66 18.81 21.78 20.12 9.99 9.82 NPK PAC (2) 81.20 71.41 18.72 20.76 18.80 20.01 24.42 21.41 9.97 10.38 (10 CCC (1) 61.33 112.47 22.64 29.77 22.90 25.84 37.02 32.94 13.02 11.98 g/plant/month) CCC (2) 78.87 74.41 19.06 20.86 18.91 20.67 24.75 22.74 10.88 10.75 Mean 88.76 90.43 21.07 25.37 20.98 22.47 30.25 26.93 11.66 12.29 0 159.84 165.14 42.27 39.51 25.05 29.54 62.33 70.36 19.88 20.70 Conventional PAC (1) 144.48 114.22 30.26 29.98 24.31 26.97 43.96 44.50 15.31 16.80 NPK PAC (2) 117.50 91.00 20.45 25.00 20.49 21.72 30.69 26.66 10.66 11.20 (14 CCC (1) 110.69 151.53 40.92 36.91 23.26 28.66 58.76 69.58 17.93 19.82 g/plant/month) CCC (2) 113.17 93.00 21.12 25.33 21.03 23.05 31.02 27.66 10.91 11.48 Mean 129.14 122.98 31.00 31.35 22.83 25.99 45.35 47.75 14.94 16.00 0 164.09 133.05 48.57 30.32 30.01 25.60 67.57 70.79 24.58 18.78 Slow release PAC (1) 115.16 109.91 36.14 27.01 25.26 25.37 55.73 36.29 18.84 15.78 NPK PAC (2) 135.97 89.50 23.29 24.01 21.43 23.48 33.48 30.32 13.43 11.87 (20 g/plant/4 CCC (1) 155.86 114.06 34.67 30.03 23.57 26.37 42.04 41.98 18.91 19.99 month) CCC (2) 140.64 90.83 23.55 24.06 22.76 23.64 34.14 31.32 13.66 12.20

Mean 142.34 107.47 33.24 27.09 24.60 24.89 46.59 42.14 17.89 15.72 0 185.10 180.77 48.70 41.94 33.01 31.14 77.59 73.62 24.72 22.70 Slow release PAC (1) 170.64 157.68 42.52 37.05 25.09 26.17 77.08 59.72 21.59 21.35 NPK PAC (2) 158.20 105.61 28.48 26.22 23.80 22.88 40.63 41.96 14.53 14.31 (28 g/plant/4 CCC (1) 168.71 173.60 38.19 40.12 25.31 29.98 68.34 67.05 21.77 21.39 month) CCC (2) 150.20 111.95 29.98 28.89 24.77 26.10 43.96 42.63 15.53 14.78

Mean 166.57 145.92 37.58 34.84 26.40 27.25 61.52 57.00 19.63 18.90 0 137.78 135.33 37.02 32.98 26.41 26.50 54.88 54.66 19.57 18.13 Mean of GR PAC (1) 115.66 98.31 29.97 26.84 22.76 23.42 43.38 35.76 15.68 14.44 PAC (2) 107.15 79.78 21.93 22.54 19.97 20.96 29.78 27.87 11.65 11.23 CCC (1) 107.79 118.04 30.77 30.69 22.02 25.38 44.57 45.82 16.22 16.29 CCC (2) 105.82 82.25 22.62 23.18 20.63 21.98 30.31 28.67 12.20 11.55 L.S.D. (0.05) Fertilization (F) 12.83 12.60 3.14 3.30 3.48 2.95 5.14 3.93 2.08 1.86 Growth retardants (GR) 12.83 12.60 3.14 3.30 3.48 2.95 5.14 3.93 2.08 1.86 FX GR 28.69 28.17 7.02 7.37 7.79 6.6 11.49 8.78 4.65 4.16 *PAC= paclobutrazol PAC (1) = 50 ppm PAC (2) = 100 ppm CCC = cycocel CCC (1) = 1000 ppm CCC (2) = 1500 ppm

Regarding the effect of growth retardants, the data in Tables (2 and 3) indicated that foliar application of PAC or CCC reduced plant height, fresh and dry weights of shoots, root length as well as fresh and dry weights of roots compared to plants sprayed with tap water (control). Generally, the reduction in the mean values was significant compared to the control. The only exceptions to this general trend were observed with foliar spaying of CCC at low concentration (1000 ppm) that caused insignificant reduction in dry weights of shoots and roots as well as root length compared to control. Moreover, in both seasons, the reduction rate in the abovementioned parameters was increased with raising PAC and CCC concentrations; therefore the severe reduction was evident at high concentration of the two growth retardants with the superior effect of PAC in this concern. The reduction in plant height by spraying growth retardants may be attributed to its impact on gibberellins biosynthesis. paclobutrazol prevents the conversion of kaurene to kaurenoic acid in the gibberellins biosynthetic pathway which leads to inhibit the formation of gibbrellin (Rademacher, 2000). Such reductions in

497 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613 plant height, aerial and underground parts as a result of foliar application of PAC or CCC are in agreement with those reported by previous researches (Mahgoub et al., 2006; Bhat et al., 2011; Harmath et al., 2014: Gholampour et al., 2015; Heikal, 2017 and Sharaf-Eldien et al., 2017). On the other hand, the data in the same Tables (2 and 3) showed that number of branches/plant, stem diameter, plant width and show value exhibited opposite trend in response to growth retardants treatments. In both seasons, foliar application of PAC or CCC concentrations resulted in significant increase in mentioned parameters compared to control. Also as the concentrations of PAC or CCC increased the recorded mean values were increased progressively compared to the control. Also in both seasons, no significant differences were detected between PAC or CCC treatments with number of branches/plant and stem diameter. However, in the case of plant width and show value, PAC was superior in its significant effect particularly at the high concentration (100 ppm). The augmentations in number of branches/plant stem diameter, plant width and show value as a result of foliar application of PAC or CCC are in conformity with that obtained by many researchers (El-Quesni et al., 2007; Khan et al., 2012; Srivastava, 2013; Youssef and Abd El-Aal, 2013; Asgarian et al., 2013; Ghatas, 2016; Abd El-Aal and Mohamed, 2017 and Sharaf-Eldien et al., 2017). The increase in number of formed branches with the application of PAC or CCC may be due to the suppression of terminal bud which resulted more branching of the studied plants (Prashanth et al., 2006 ) or may be attributed to increase the level of cytokinins hormones that enhancing number of branches, and this accompanied by reducing levels of indole acetic acids and gibberellins that lead to inhibition of apical dominance and more formation of branches (Fletcher,2000; Rademacher,2000 and Singh and Bist, 2003). The increase in cytokinins content and reduction in indole acids beside gibberellins due to PAC or CCC has been confirmed by recent studies (Youssef and Abd El-Aal, 2013 and Abd El-Aal and Mohamed, 2017). Concerning the effect of interaction between fertilization and growth retardants treatments, the data in Tables (2 and 3) illustrated that, in both seasons the shortest plants were those unfertilized and sprayed with PAC (100 ppm), the lowest values of fresh and dry weights of shoots, root length as well as fresh and dry weights of roots were obtained from unfertilized plants and sprayed with CCC (1000 ppm), whereas the highest values of these traits were gained from plants fertilized with Osmocote (28 g/plant/ 4 month) ) and sprayed with tap water. Meanwhile in the case of number of branches/plant, stem diameter, plant width and show value the interactions between NPK fertilizer and growth retardants significantly increased the mean values of these parameters compared to the control plants (received no treatments). In both seasons, the lowest values of such attributes were obtained from the plants did not receive any treatments (control), while the highest values were resulted from plants fertilized with Osmocote at rat (28 g/plant/ 4 month) and sprayed with PAC at (100 ppm).

B. Flowering parameters

The results in Tables (4) revealed that, flowers number/plant, flowers diameter and flowers fresh and dry weights were increased with addition of both chemical fertilizers (conventional NPK and Osmocote) compared to unfertilized control plants. In both seasons, the increase in mean values was statistically significant in most cases compared to control, except in the second season with the lowest rate of conventional NPK (10 g/plant/month) which resulted insignificant increase in flowers number/plant, flowers diameter and flowers dry weights compared to control. The data in same table also showed that within each type of different fertilizers, increasing the application rate caused a gradual increase in flowering parameters. Among different fertilization treatments, the slow -release fertilizer (Osmocote) was more effective than conventional NPK fertilization in most cases. Similar increases in flowering parameters due to addition of slow -release NPK fertilizer are in agreement with that obtained by other studies (Yahya et al., 1999; Asrar et al., 2014 and Matysiak and Nogowska, 2016 ). The positive influence of fertilization treatments (conventional or slow -release NPK fertilizer) on inceasing the vegetative growth and flowering traits compared to the control can be elucidated by the vital role of N, P and K in the various physiological processes within the plant, that in turn affect the plant growth traits. nitrogen is present in the structure of protein molecules, phosphorus is an essential component of nucleic acids and phospholipids, while potassium is essential as an activator for enzymes involved in the synthesis of certain peptide bonds (Devlin, 1975).

498 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613

Concerning the effect of growth retardants treatments, the data in Tables (4) showed that foliar spraying of PAC (100 ppm) was the only treatment caused significant increase in flowers number/plant as well as flowers fresh and dry weights, while the other concentrations of two growth retardants had no significant effect on these parameters compared to control plants. The obtained increases in flowering traits due to foliar application PAC are coincided with those obtained by prior researches (Mahgoub et al., 2006 El-Quesni et al., 2007; Rathore et al., 2011; Youssef and Abd El-Aal, 2013; Asgarian et al., 2013; Ghatas, 2016; Abd El-Aal and Mohamed, 2017 Heikal, 2017 and Sharaf-Eldien et al., 2017).

Table 4: Effect of fertilization, growth retardants treatments and their interactions on flowers number, flowers diameter as well as flowers fresh and dry weights of Euryops pectinatus during the 2016 and 2017 seasons. Flowers number Flowers Flowers fresh Flowers dry Fertilization (F) /plant diameter (cm) weight (g/plant) weight (g/plant) *GR,(ppm) 2016 2017 2016 2017 2016 2017 2016 2017 0 19.67 19.41 3.63 2.96 2.95 2.54 1.37 1.18 Control PAC (1) 20.67 21.11 2.91 2.96 4.11 4.00 1.60 2.23 PAC (2) 21.56 19.92 2.74 2.96 5.29 5.09 2.03 2.17 CCC (1) 20.44 21.85 3.61 2.86 4.87 3.49 1.84 1.82 CCC (2) 21.44 22.03 2.64 2.83 3.09 2.94 1.14 1.62 Mean 20.76 20.87 3.11 2.91 4.06 3.61 1.60 1.80 0 22.56 21.41 3.67 3.16 6.26 5.17 2.68 1.73 Conventional NPK PAC (1) 23.66 21.37 3.52 3.08 8.44 8.74 3.01 2.00 (10 g/plant/month) PAC (2) 24.00 23.52 3.76 2.88 10.79 8.14 3.15 2.18 CCC (1) 21.44 21.85 3.61 3.09 5.13 5.76 1.96 1.85 CCC (2) 23.33 21.37 3.56 3.01 6.42 5.84 2.97 2.03 Mean 23.00 21.90 3.62 3.05 7.41 6.73 2.75 1.96 0 22.89 23.52 3.77 3.28 7.16 7.66 2.80 2.30 Conventional NPK PAC (1) 25.11 23.52 3.62 3.13 8.01 7.11 2.66 2.22 (14 g/plant/month) PAC (2) 25.22 24.03 3.60 3.13 7.75 8.89 3.24 2.53 CCC (1) 22.66 22.63 3.64 3.13 8.94 4.32 3.61 2.23 CCC (2) 23.67 22.70 3.62 3.03 5.90 6.91 3.09 2.28 Mean 23.91 23.28 3.65 3.14 7.55 6.98 3.08 2.31 0 23.67 23.41 3.83 3.25 8.40 7.92 2.86 2.66 Slow release NPK PAC (1) 23.33 20.59 3.78 3.02 5.25 8.18 2.78 2.52 (20 g/plant/4 month) PAC (2) 24.66 23.70 3.57 2.96 9.21 7.33 2.84 2.66 CCC (1) 24.22 22.74 3.64 3.24 6.57 8.98 2.62 2.50 CCC (2) 24.11 21.74 3.56 3.03 7.65 5.25 2.72 1.63 Mean 24.00 22.44 3.68 3.10 7.42 7.53 2.77 2.40 0 24.22 21.81 3.91 3.60 10.01 7.34 2.73 1.89 Slow release NPK PAC (1) 22.56 22.74 3.83 3.42 10.64 6.99 3.31 2.51 (28 g/plant/4 month) PAC (2) 25.66 25.70 3.62 2.99 10.93 7.52 3.77 2.65 CCC (1) 25.22 22.15 3.80 3.15 9.57 7.30 2.79 2.12 CCC (2) 22.56 24.19 3.72 2.92 11.08 9.62 3.78 3.10 Mean 24.04 23.32 3.78 3.21 10.44 7.76 3.28 2.45 0 22.60 21.91 3.76 3.25 6.96 6.13 2.49 1.95 Mean of GR PAC (1) 23.07 21.87 3.53 3.12 7.29 7.00 2.67 2.30 PAC (2) 24.22 23.38 3.46 2.98 8.79 7.39 3.01 2.44 CCC (1) 22.80 22.25 3.66 3.09 7.02 5.97 2.57 2.10 CCC (2) 23.02 22.41 3.42 2.96 6.83 6.11 2.74 2.13 L.S.D. (0.05) Fertilization (F) 1.28 1.35 0.26 0.24 1.19 0.98 0.47 0.45 Growth retardants (GR) 1.28 1.35 0.26 0.24 1.19 0.98 0.47 0.45 FX GR 2.86 3.02 0.59 0.54 2.66 2.18 1.06 1.01 *PAC= paclobutrazol PAC (1) = 50 ppm PAC (2) = 100 ppm CCC = cycocel CCC (1) = 1000 ppm CCC (2) = 1500 ppm

In the case of flowers diameter, the data in Tables (4) indicated that the recorded values were decreased steadily with raising the concentration of PAC or CCC compared to control. In both seasons, the reduction in flowers diameter was statistically insignificant at the lower concentrations of both growth retardants, whereas the higher concentrations caused significant reduction in the recorded values compared to control. The present findings are in accordance with findings of Sharaf-Eldien et al. (2017)

499 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613 on Zinnia elegans, they found that diameter of flowers was reduced due to foliar application PAC at 50-150 ppm, and similar results were reported by Biswas et al. (2018) on Pansy (Viola x wittrockiana Gams.). Moreover, Pinto et al. (2005) Zinnia elegans found that application of CCC at 1000 ppm had no effect on flower diameter. Regarding the effect of interaction between fertilization and growth retardants treatments, the data in Tables (4) indicated that overall, plants receiving both fertilization and growth retardants treatments had significantly higher values of flowers number/plant, flowers fresh and dry weights than those recorded with the control. In both seasons, the lowest values of flowers number/plant and flowers fresh and dry weights were obtained from the control plants (received no treatments), whereas the highest values of flowers number/plant were gained from plants fertilized with Osmocote (28 g/plant/ 4 month) and sprayed with PAC (100 ppm), the corresponding highest values of flowers fresh and dry weights were obtained from plants fertilized with Osmocote at the same rate (28 g/plant/ 4 month) and sprayed with CCC (1500 ppm). In the case of flowers diameter, the highest values were produced from plants fertilized with Osmocote (28 g/plant/ 4 month) and sprayed with tap water, meanwhile the lowest values were resulted from unfertilized plants and sprayed with CCC at 1500 ppm in both seasons.

C. Chemical constituents

1. Total chlorophyll and Total carbohydrate contents

As shown from data in Table (5) fertilization treatments had a favorable effect on synthesis and accumulation of total chlorophyll content in leaves and total carbohydrate content in shoot of Euryops pectinatus plants. In both seasons, plants received any rat of the fertilization treatments had significantly higher values than unfertilized control plants. Also, raising the application rate of two fertilizers type caused steady increase in total chlorophyll and total carbohydrate. In both seasons, no significant differences were detected due to addition low rates of conventional NPK or Osmocote, while Osmocote at the high rate (28 g/plant/ 4month) appeared to be more effective since significantly donate higher values than conventional NPK fertilizer in most cases. The augmentation in total chlorophyll and total carbohydrate as result of chemical NPK treatments are in conformity with the finding of other researches (Habib, 2012, Abou Dahab et al. 2017), while such increases due to addition of slow -release NPK fertilizer are in agreement with that recorded by previous studies (El-Naggar et al., 2010 and Asrar et al., 2014). In this concern, Hussein (2009) reported that total chlorophylls and total carbohydrate were increased as a result of addition either conventional or slow -release NPK fertilizer with the superiority of the later. As for effect of growth retardants treatments, the data in Tables (5) showed that both total chlorophyll and total carbohydrate were increased significantly owing to foliar spraying of PAC or CCC concentrations compared to the control. In both seasons, the recorded mean values were increased steadily parallel with the concentration of both growth retardants treatments compared to the control with no significant differences between them in most cases. The augmentations in total chlorophyll due to PAC or CCC may be attributed to the role of growth retardants on stimulating the synthesis of endogenous cytokinins that enhances differentiation of chloroplast, biosynthesis of chlorophyll, and retards degradation of chlorophyll (Fletcher et al., 2000), while the increase in total carbohydrate may be indirectly attributed to chlorophyll increase in leaves which led to more photosynthetic process and consequently more production and accumulation of carbohydrate in shoots. A similar effect of PAC or CCC treatments on increasing total chlorophyll and total carbohydrates was obtained by other researches (Mahgoub et al., 2006; El-Quesni et al., 2007; Youssef and Abd El-Aal, 2013; Ghatas, 2016; Abd El-Aal and Mohamed, 2017; Heikal, 2017 and Sharaf-Eldien et al., 2017). Respecting interaction between the fertilization and growth retardants treatments, the data in Tables (5) indicated that, in most cases, the plants receiving both fertilizers and growth retardants treatments had significantly higher values of total chlorophyll and total carbohydrate than those recorded with control ( plants received no treatments). In both seasons, the highest values of two chemical constituents were obtained from plants fertilized with Osmocote (28 g/plant/ 4 month) and sprayed with PAC (100 ppm), meanwhile the lowest values were registered with the control plants.

500 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613

Table 5: Effect of fertilization, growth retardants treatments and their interactions on total chlorophylls, total carbohydrates as well as N, P and K% in dried shoots of Euryops pectinatus during the 2016 and 2017 seasons. Total Total N P K *GR, chlorophylls Carbohyd (% dry (% dry (% Fertilization (F) (pp content rates matter) matter) dry matter) m) (SPAD) (% of dry matter) 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 0 32.23 31.42 12.32 13.86 1.26 1.45 0.14 0.16 1.34 1.40 Control PAC (1) 36.57 34.99 14.29 14.58 1.46 1.53 0.16 0.17 1.39 1.47 PAC (2) 39.00 39.65 16.07 16.57 1.62 1.61 0.18 0.18 1.52 1.49 CCC (1) 34.83 34.67 16.89 15.87 1.40 1.58 0.14 0.18 1.36 1.42 CCC (2) 33.20 35.91 16.42 17.25 1.53 1.70 0.16 0.19 1.44 1.42 Mean 35.17 35.33 15.20 15.63 1.45 1.57 0.16 0.18 1.41 1.44 0 33.81 36.43 15.66 17.01 1.40 1.69 0.15 0.19 1.40 1.46 Conventional PAC (1) 51.01 45.80 18.05 18.54 1.53 1.81 0.17 0.23 1.47 1.59 NPK PAC (2) 56.45 47.62 19.58 22.13 1.80 2.13 0.19 0.24 1.41 1.68 (10 CCC (1) 45.91 46.58 18.70 21.32 1.64 1.51 0.18 0.19 1.62 1.69 g/plant/month) CCC (2) 53.31 52.28 18.59 24.46 1.87 2.08 0.22 0.21 1.69 1.60 Mean 48.10 45.74 18.11 20.69 1.65 1.84 0.18 0.21 1.52 1.60 0 39.65 48.04 15.75 18.01 1.37 1.44 0.16 0.16 1.40 1.44 Conventional PAC (1) 54.11 48.29 18.59 19.43 1.82 1.88 0.20 0.24 1.76 1.65 NPK PAC (2) 57.92 48.70 20.71 22.11 2.03 2.11 0.21 0.23 1.65 1.70 (14 CCC (1) 50.18 48.30 18.58 21.35 1.65 2.04 0.18 0.19 1.63 1.67 g/plant/month) CCC (2) 53.98 54.36 18.52 23.95 1.86 2.02 0.20 0.26 1.63 1.66 Mean 51.17 49.54 18.43 20.97 1.75 1.90 0.19 0.22 1.61 1.62 0 42.59 47.76 17.25 17.07 1.59 1.69 0.20 0.19 1.42 1.51 Slow release PAC (1) 47.19 49.86 21.32 24.21 1.89 2.36 0.20 0.27 1.66 1.68 NPK PAC (2) 56.98 48.13 22.05 21.51 2.15 2.05 0.23 0.22 1.81 1.73 (20 g/plant/4 CCC (1) 50.51 49.59 20.99 21.81 2.13 2.11 0.23 0.24 1.67 1.62 month) CCC (2) 46.01 42.13 20.93 19.38 2.10 1.87 0.23 0.24 1.71 1.66 Mean 48.66 47.50 20.51 20.80 1.97 2.02 0.22 0.23 1.65 1.64 0 44.94 46.45 19.13 21.97 1.78 2.17 0.20 0.18 1.46 1.49 Slow release PAC (1) 56.71 53.81 27.31 23.67 2.71 2.28 0.29 0.22 1.81 1.72 NPK PAC (2) 57.30 59.82 27.68 26.35 2.73 2.50 0.32 0.29 1.90 1.93 (28 g/plant/4 CCC (1) 52.10 50.59 25.68 22.84 2.52 2.21 0.27 0.24 1.78 1.69 month) CCC (2) 47.55 54.82 24.92 24.75 2.45 2.37 0.26 0.24 1.73 1.73 Mean 51.72 53.10 24.94 23.92 2.44 2.31 0.27 0.23 1.74 1.71 0 38.64 42.02 16.02 17.58 1.48 1.69 0.17 0.18 1.41 1.46 Mean of GR PAC (1) 49.12 46.55 19.91 20.09 1.88 1.97 0.20 0.22 1.62 1.62 PAC (2) 53.53 48.78 21.22 21.73 2.06 2.08 0.23 0.23 1.66 1.71 CCC (1) 46.71 45.95 20.17 20.64 1.87 1.89 0.20 0.21 1.61 1.62 CCC (2) 46.81 47.90 19.88 21.96 1.96 2.01 0.21 0.23 1.64 1.61 L.S.D. (0.05) Fertilization (F) 7.46 3.50 2.82 2.08 0.28 0.19 0.03 0.02 0.20 0.15 Growth retardants (GR) 7.46 3.50 2.82 2.08 0.28 0.19 0.03 0.02 0.20 0.15 FX GR 16.68 7.82 6.30 4.65 0.64 0.42 0.07 0.05 0.45 0.32 *PAC= paclobutrazol PAC (1) = 50 ppm PAC (2) = 100 ppm CCC = cycocel CCC (1) = 1000 ppm CCC (2) = 1500 ppm

2. Contents of N, P and K (% of dry matter)

Chemical analysis of shoots (Table 5) revealed that, accumulation of the three elements (N, P and K %) in shoot of Euryops pectinatus plants were prominently improved by addition of both different fertilizers treatments. In both seasons, the values of N, P and K % were augmented significantly in shoot of plants received either conventional NPK or Osmocote treatments, except in the case of conventional NPK (10 g/plant/months) which caused insignificant increase in the three elements in the first season compared to untreated control plants. It's also cleared from the data in Table (5) that, regardless of the fertilizer type, three nutrients were increased steadily with raising the application rate, with the superiority of Osmocote (slow -release NPK fertilizer) on accumulation of elements in shoots. Such increase in N, P or K % as a result of using slow -release NPK are in accordance with findings of prior studies (Yahya et al., 1999; El-Naggar et al., 2010; Schroeter-Zakrzewska and Kleiber, 2012; Kaplan

501 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613 et al., 2013 and Asrar et al., 2014). Moreover, the superior effect of the slow -release NPK fertilizer on increasing N, P and K % compared to conventional one has been obtained by Hussein (2009). The augmentation in such three elements in shoot tissues with raising the fertilization rates may be due to the increase in N, P and K levels in the root medium that accompanied by more uptake of such elements from the soil and their accumulation in plant tissues (Jain, 1983), and this reflecting the marked increase in the studied vegetative growth and flowering attributes of Euryops pectinatus plants. With regard to the effect of growth retardants treatments, data in Table (5) showed that foliar application of PAC or CCC significantly increased N, P and K % as compared to control. Also, with raising the concentration of the two types of growth retardants, the values of the three elements were increased steadily compared to control, with no significant difference were detected between both growth retardants treatments in most cases. The increments in N, P or K % with foliar application of PAC or CCC are in harmony with those obtained by other researches (El-Quesni et al., 2007; Youssef and Abd El-Aal, 2013; Matsoukis et al., 2015; Ghatas, 2016; Abd El-Aal and Mohamed, 2017 and Sharaf-Eldien et al., 2017). Concerning interaction between fertilizers and growth retardants, data in Table (5) indicated that, the interactions between the different treatments increased the mean values of the three elements as compared to control plants. In both seasons, generally, the lowest values of three elements were scored with plants did not receive any treatment (control), whereas the highest values were registered with plants fertilized with Osmocote (28 g/plant/ 4 month) and sprayed with PAC 100 ppm.

3. Contents of Fe, Mn and Zn (ppm)

Data presented in Table (6) revealed that, on the whole, addition of either conventional NPK or slow-release fertilizers significantly increased accumulation of Fe, Mn and Zn contents in shoot compared to control plants. The exception to this trend was detected with low rate of slow-release fertilizers Osmocote (20 g/plant/4months) which caused insignificant increase in accumulation of Fe content in both seasons compared to control. Similar increase in Fe, Mn or Zn contents resulted from application of conventional NPK or slow-release fertilizers treatments have been reported by previous studies (Sakr et al., 2008 and Schroeter-Zakrzewska and Kleiber, 2012). The positive effect of fertilization treatments on stimulating root growth parameters may be lead to enhance the absorption of various macro- and micronutrients needed for growth and development. As for effect of growth retardants treatments, the data presented in in Table (6) showed that the content of Fe, Mn and Zn were generally increased in response to foliar application of PAC or CCC compared to the control. Generally, the increase was statistically significant except in the case of spraying CCC both two concentrations which caused insignificant increase in Fe content in both seasons compared to the control. Among the two types of growth retardants, PAC was superior in accumulation of the three elements in shoot with no significant differences detected between the lowest and the high rate in this concern. Such increase in Fe, Mn or Zn contents with foliar application of PAC or CCC is in harmony with those reported by previous researches (Matsoukis et al., 2015 and Heikal, 2017). With regard to effect of interaction between the fertilization and growth retardants treatments, the data in Table (6) indicated that, the combination between different treatments increased the content of Fe, Mn and Zn content as compared to control plants (received no treatments). In both seasons, the highest values of the three elements were obtained from the plants fertilized with conventional NPK (10 g/plant/month) and sprayed with PAC 100 ppm, whereas the lowest values of three elements were scored with the control plants.

4. Contents of total indoles and phenols

The data in Table (6) disclosed that, total indoles and phenols content in the leaves were increased significantly as a result of conventional NPK or slow-release fertilizers treatments compared to untreated control plants. Such increase in indoles and phenols content as a result of chemical NPK treatment are in agreement with findings of Abou Dahab et al. (2017). Concerning the effect of growth retardants treatments, data in Table (6) showed that in most cases, total indoles were reduced significantly due to spray either PAC or CCC compared to the control,

502 Middle East J. Appl. Sci., 8(2): 492-507, 2018 ISSN 2077-4613 with only exception observed in the first season with CCC (1000 ppm) which had insignificant lower values than those of control plants. On the other hand, the content of total phenols was augmented significantly in response to foliar application of PAC and CCC with their two concentrations compared to the control. These results are in agreement with finding of Ghatas (2016) and Abd El-Aal and Mohamed (2017), as they reported reduction in total indoles content and increasing in total phenols content as a result of PAC or CCC treatments.

Table 6: Effect of fertilization, growth retardants treatments and their interactions on Fe, Mn and Zn contents in dried shoots as well as total indoles and phenols content in leaves of Euryops pectinatus during the 2016 and 2017 seasons. Fe (ppm) Mn (ppm) Mn (ppm) Total indoles Total phenols (mg/100g F.W) (mg/100g F.W) Fertilization (F) *GR,(ppm) 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 0 86.28 72.06 43.29 35.93 36.50 40.49 180.72 179.00 126.24 120.29 Control PAC (1) 116.48 124.29 64.13 76.46 54.29 54.81 178.90 175.48 133.75 129.93 PAC (2) 103.66 128.46 62.40 56.45 47.74 57.62 174.93 167.51 133.74 134.95 CCC (1) 102.04 117.70 59.12 60.39 37.60 60.66 175.18 175.14 130.36 131.02 CCC (2) 104.55 93.89 53.09 49.04 46.64 55.20 178.05 176.26 129.42 125.32 Mean 102.60 107.28 56.40 55.65 44.55 53.76 177.56 174.68 130.70 128.30 0 108.34 106.25 58.66 58.85 60.81 51.48 214.58 199.91 132.11 138.97 Conventional PAC (1) 133.89 152.62 76.97 85.69 69.85 81.80 179.44 181.46 135.81 147.71 NPK PAC (2) 161.34 158.11 85.34 86.53 97.65 95.75 184.65 178.06 137.22 149.76 (10 CCC (1) 95.12 113.84 56.54 64.83 59.72 50.11 203.23 193.94 131.69 134.15 g/plant/month) CCC (2) 110.21 114.96 61.59 62.81 63.85 50.32 188.52 183.11 135.07 146.79 Mean 121.78 129.16 67.82 71.74 70.38 65.89 194.08 187.30 134.38 143.48 0 118.87 138.58 69.49 70.75 72.36 70.35 221.41 238.69 136.42 140.98 Conventional PAC (1) 128.82 131.39 70.04 71.38 72.61 71.34 209.17 209.04 138.24 145.74 NPK PAC (2) 125.82 137.90 71.51 82.64 73.47 71.83 186.93 189.43 140.82 152.62 (14 CCC (1) 139.70 95.20 64.67 66.01 66.24 50.90 219.13 229.22 135.96 153.01 g/plant/month) CCC (2) 104.17 112.16 59.51 60.58 61.94 61.87 191.51 185.16 136.85 148.58 Mean 123.48 123.05 67.04 70.27 69.33 65.26 205.63 210.31 137.66 148.19 0 102.63 109.17 58.14 79.82 61.28 51.06 229.00 242.47 140.15 142.18 Slow release PAC (1) 107.61 111.77 59.97 62.16 68.95 67.83 216.82 194.29 144.54 144.65 NPK PAC (2) 109.86 103.27 58.45 65.59 73.85 65.14 193.71 192.40 143.99 149.55 (20 g/plant/4 CCC (1) 86.50 119.77 56.44 58.06 59.24 69.49 214.35 199.96 145.81 144.11 month) CCC (2) 129.18 105.80 63.81 65.12 87.60 69.94 197.22 190.06 136.99 145.07

Mean 107.16 109.95 59.36 66.15 70.18 64.69 210.22 203.84 142.30 145.11 0 117.09 103.40 60.19 61.17 70.51 63.48 224.50 232.34 134.84 145.45 Slow release PAC (1) 122.76 143.23 72.15 73.69 74.71 80.96 228.77 241.72 145.98 154.66 NPK PAC (2) 125.34 115.23 66.24 76.50 67.65 76.32 205.54 198.57 147.46 160.98 (28 g/plant/4 CCC (1) 113.13 103.03 59.16 60.25 82.09 56.32 228.17 234.93 142.00 147.51 month) CCC (2) 126.69 122.90 68.51 86.29 70.04 70.58 202.97 203.96 149.36 160.15

Mean 121.00 117.56 65.25 71.58 73.00 69.53 217.99 222.30 143.93 153.75 0 106.64 105.89 57.96 61.30 60.29 55.37 214.04 218.48 133.95 137.57 Mean of GR PAC (1) 121.91 132.66 68.65 73.87 68.08 71.35 202.62 200.40 139.66 144.54 PAC (2) 125.20 128.59 68.79 73.54 72.07 73.33 189.15 185.19 140.65 149.57 CCC (1) 107.30 109.91 59.18 61.91 60.98 57.50 208.01 206.64 137.16 141.96 CCC (2) 114.96 109.94 61.30 64.77 66.01 61.58 191.66 187.71 137.54 145.18 L.S.D. (0.05) Fertilization (F) 10.59 9.65 0.52 0.51 5.60 1.92 6.79 5.34 1.73 2.69 Growth retardants (GR) 10.59 9.65 0.52 0.51 5.60 1.92 6.79 5.34 1.73 2.69 FX GR 23.68 21.58 1.16 1.14 12.51 4.29 15.18 11.94 3.88 6.02 *PAC= paclobutrazol PAC (1) = 50 ppm PAC (2) = 100 ppm CCC = cycocel CCC (1) = 1000 ppm CCC (2) = 1500 ppm

Respecting the effect of the interaction between the fertilizers and growth retardants treatments, the data in Tables (6) indicated that the highest values of total indoles content ( 229.00 and 242.47 mg/100g F.W in the first and second seasons, respectively) were obtained from the plants fertilized with Osmocote (20 g/plant/ 4 month) and sprayed with tap water, while the lowest values ( 174.93 and 167.51 mg/100g F.W in the two seasons, respectively) were scored with the unfertilized plants sprayed with

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PAC at 100 ppm. In the case of total phenols content, the lowest values (126.24 and 120.29 mg/100g F.W in the first and second seasons, respectively) were obtained from control plants, whereas the highest contents (149.36 and 160.98 mg/100g F.W) were registered with plants fertilized with Osmocote at 28 g/plant/ 4 month and sprayed with CCC at 1500 ppm in the first season and PAC at 100 ppm in the second one, respectively.

D. Anatomical study

Figures (a and b) evidently that, there were differences of leaves anatomy between control plants (a) and the best combined treatment (b), where application of combined treatment Osmocote at 28 g/plant/ 4 month and foliar spraying with PAC at 100 ppm significantly increased leaf anatomy features represented in thickness of midrib, length and width of vascular bundle, phloem and xylem tissues and number of xylem vessels in vascular bundle as well as the leaf blade thickness compared to control plants. Limelight on mesophyll tissue, intercellular air spaces, thickness of both spongy and palisade tissues were increased with combined treatment to reach (133083 µ) while in control, the same tissue thickness reached (97947.5 µ).

a) b) Escalating of vascular tissues are evident for that could reverse upon enhancement translocation of nutrients from soil and the photosynthates from leaves to different plant parts Marschner (1995). Moreover applied such growth retardants with fertilizer maybe reflect the well-built growth leaf tissue which means more longevity comparing with tissue of control plants. Variation of leaves tissues between combined treatment and control maybe due to interaction of endogenous phytohormones and foliar spraying with such growth retardants caused change in tissues development and morphogenesis. Youssef and Abd El-Aal (2013).

Conclusion

From the obtained results it can be concluded that Osmocote as slow release NPK fertilizer was more effective in improving vegetative growth and flowering parameters as well as chemical constituents especially at the high rat (28 g/plant/ 4month) compared with conventional NPK fertilizer that provided equivalent levels of nutrients. PAC was superior to CCC in controlling plant height and achieving a good display (show value) particularly at the high concentration (100 ppm). The combined treatment Osmocote at 28 g/plant/ 4 month and foliar spraying with PAC at 100 ppm produced the highest rate of show value, flowers number/plant as well as contents of total chlorophylls, total carbohydrates, N, P, K %. Based on the experiment results it can be recommended that for the production of Euryops pectinatus as a flowering pot plant, it should be fertilized with Osmocote (18 N - 6 P2O5 - 12 K2O) at the rate of 28 g/plant/ 4 month and sprayed monthly with PAC at the rate of 100 ppm.

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