Response of seed yield and fatty acid compositions for some sunflower genotypes to plant spacing and nitrogen fertilization

Accepted Manuscript Response of seed yield and fatty acid compositions for some sunflower genotypes to plant spacing and nitrogen fertilization Mohamed Ali Abd EL-Satar, Asmaa Abd-EL-Halime Ahmed, Tamer Hassan Ali Hassan PII: DOI: Reference:

S2214-3173(17)30014-8 http://dx.doi.org/10.1016/j.inpa.2017.05.003 INPA 85

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Information Processing in Agriculture

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28 January 2017 4 April 2017 22 May 2017

Please cite this article as: M.A.A. EL-Satar, A.A-E. Ahmed, T.H.A. Hassan, Response of seed yield and fatty acid compositions for some sunflower genotypes to plant spacing and nitrogen fertilization, Information Processing in Agriculture (2017), doi: http://dx.doi.org/10.1016/j.inpa.2017.05.003

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INFORMATION PROCESSING IN AGRICULTURE XXX (2017) XXX–XXX

jo u rn a l h o m e p a g e : w w w . e l s e v ie r .c o m / lo c a te / i n p a

Response of seed yield and fatty acid compositions for some sunflower genotypes to plant spacing and nitrogen fertilization Mohamed Ali Abd EL-Satar*; Asmaa Abd-EL-Halime Ahmed and Tamer Hassan Ali Hassan Oil Crops Research Department, Field Crops Research Institute, Agricultural Research Center, 9 El-Gamaa St. Giza, Egypt ARTICLE I NFO

ABSTRACT Article history: Received Accepted Available online xxxx

Keywords sunflower, plant spacing, nitrogen fertilization, genotypes, seed yield, fatty acids

A field experiment was conducted at the experiment Farm of Kafr-El-Hamam Research Station, Zagazig, Sharkia Governorate, Agricultural Research Center, Egypt during the two successive summer seasons of 2013 and 2014 to achieve the highest yield and good oil quality of three tested sunflower genotypes. In both seasons, the experiment was conducted by using the split split plot design in randomized complete block design with three replicates arrangement keeping plant spaces (15, 20 and 25 cm apart between hills) in main plots, nitrogen fertilization levels (15, 30 and 45 N fad. -1) in sub plots and sunflower genotypes (Giza 102, Sakha 53 and promising line of L120) in sub sub plots. Yield and quality traits were significantly influenced by plant spaces, nitrogen fertilization levels and cultivars as well as interactions in both seasons and their combined analysis. The wider plant spacing of 25 cm seems to be a good compromise between the highest seed yield fad.-1 and good acid composition of oil. Gradually increasing of nitrogen fertilization level had a positive reflected on yield and desirable acid composition of oil. Sakha 53 was ranked in the first order in stem diameter, head diameter, 100 -seed weight, seed weight plant -1, flowered late and hence seed yield fad.-1 as well as seed oil content whereas, Giza 102 characterized with its contained the highest proportion of oleic and linoleic unsaturated fatty acids.The highest values of head diameter, 100-seed weight, seed weight plant -1 and hence seed yield fad.-1 as well as the highest proportion of oleic and linoleic unsaturated fatty acids composition were obtained by grown sunflower cv. Sakha 53 at wider spacing of 25 cm with application of nitrogen fertilization levels of 45 N fad. -1. Correlation and path analyses revealed that 100-seed weight and head diameter had the highest direct and indirect influence on seed weight plant -1, at the same time also, oleic acid content and linoleic acid content had the highest direct and indirect effect influence on seed oil content indicating their importance as selection criteria to improve yield and oil quality of sunflower.

* Corresponding author. E-mail address: [email protected]

Fax: +20 (35687893) Tel: +20 (01140376472) 1.

INTRODUCTION

Egypt has been facing acute shortage of edible oil with rapidly growing population, and the country has to supplement the needs for oil to meet the annual requirements by importing. Sunflower (Helianthus annuus L.) is considered a good candidate of oilseed crops for bridging the gap between demand and supply of edible oil. Therefore, great emphasis should be given towards an improvement of seed yield and oil quality in sunflower. Consequently, cultivating promising genotypes with high yielding ability and applying favorable agricultural practices as plant spacing and nitrogen fertilization offer a great opportunity to improve seed yield and oil quality of sunflower. Plant spacing is one of the most important agronomic practices that affect seed production and fatty acids composition of sunflower oils. It has been found to have positive influence on days to 50 % flowering [8]; stem diameter, head diameter, thousand seed weight, seed weight plant-1 and seed yield fad.-1 [9, 19, 17, 28, 6, 26, 15, 8 and 3] as well as oleic and linoleic unsaturated fatty acids composition of oil [15 and 10]. On the other hand, it has been found to have negative

influence on plant height [28 and 15]; seed oil content [11, 15, 10 and 3] as well as palmatic and stearic saturated fatty acids composition of oils [15 and 10]. Fertilization, in general and particularly with nitrogen, is considered as one of the major factors that greatly affect seed yield and oil quality of sunflower [12, 5, 23, 1, 21 and 20]. In this concern, [21] reported that 100 kg N ha-1 was suitable for sunflower and the higher rate 150 kg N ha-1 indicates a negative effect on the oil contents and seed yield. However, [14] reported that 80 kg N ha-1 was sufficient for sunflower fertilization. Also, the response of sunflower to nitrogen fertilizer levels was studied by [6, 2, 8 and 3] reported that nitrogen application markedly enhanced growth and yield but resulted in sharp decrease in seed oil percentage. Moreover, [27] in Bulgaria, showed that the high N rate (180 kg ha-1) decreased the seed oil content and the sum of unsaturated fatty acid (oleic and linoliec) and increased the sum of saturated fatty acid (stearic and palmitic). [24] in Czech Republic, They awarded that the N applicant didn’t significantly change the content of fatty acids. [29] in USA, revealed that N application rate and genotype may significantly modify fatty acid composition and oil content of sunflower grown in Mississipi, so

suggesting that these could be used as management tools for optimum plant spacing, nitrogen fertilization level for achieving the decreased total saturated fatty acid (TSFA) and increased oil content. highest seed yield and good oil quality of three sunflower genotypes, [4] observed that increasing nitrogen levels resulted in steady besides to determine the relationships between yield and yield increases in yield, the protein contents and linoleic acid, whereas, oil attributes as well as seed oil content and major fatty acids composition content and percentage of oleic acid responded negatively. using simple correlation coefficient and path analysis as selection Sunflower genotypes vary widely and were reported to criteria for improving yield and oil quality of sunflower. significantly differ in yield and yield attributes as well as its quality which represents seed oil and protein contents and fatty acids 2. MATERIALS AND METHODS composition [15 and 3]. [2] found that the interaction between hybrids x nitrogen was significant for plant height, head diameter 2.1. Site description and seed yield ha-1 but insignificant for 1000-seed weight. [20] revealed also that, yield potential of Hysun-38 could be exploited by A field experiment was conducted at the experiment Farm of Kafr-Eladdition of N fertilizer at the rate of 180 kg N ha−1 under sub-humid Hamam Research Station, Zagazig, Sharkia Governorate, Agricultural environment. Similarly, [15] revealed that significant interaction Research Center, Egypt (30 O 58\ N, 31o 50\ E) during the two successive between plant density x hybrid for yield and yield components as summer seasons of 2013 and 2014 to achieve the highest yield and well as main fatty acids composition like, palmatic, stearic, oleic and good oil quality of three tested sunflower genotypes. Soil samples (0-30 linoleic acids. cm) collected from the experimental site and analyzed for physicIn view of the importance of plant spacing, nitrogen fertilization chemical characteristics as suggested by [16] and results are and genotypes, the present investigation was designed to determine summarized in Table 1. The previous crop in both seasons was wheat. Table 1- Pre-sowing and post-harvesting mechanical and chemical analysis of soil properties at 0-30 cm depth of soil

Season

2013 2014

Available (ppm) N

P

K

40 39

14.8 15.7

243.2 331

Ph 8.1 7.8

Pre-sowing EC mmh/c CaCo3 % m 1.34 2.5 1.61 2.7

Clay %

Silt %

Fine sand %

Texture

42.60 44.83

29.43 30.50

27.97 24.67

Clay loam Clay loam

Post-harvesting Available (ppm)

Season 2013 2014

N 35 32

P 11.3 12.1

K 210 252

Ph

EC mmh/c m

CaCo3 %

Clay %

Silt %

Fine sand %

Texture

7.1 7.3

1.29 1.27

2.1 2.3

45.3 43.6

28.3 26.6

26.4 29.8

Clay loam Clay loam

2.2. Experimental design The tested treatments consisted of factorial combination of three plant spacing (15, 20 and 25 cm), three nitrogen fertilization levels (15, 30 and 45 N fad.-1) and three genotypes (Giza 102, Sakha 53 and promising line of L120). The experimental design was a split split plot in randomized complete block arrangements with three replications. Plant spacing was allotted for the main plots; nitrogen fertilization levels was occupied the sub plots and sunflower genotypes was devoted for the sub sub plots. Each sub sub plot area was 9 m2 (5 ridges, 60 cm apart and 3 m long). Tested Sunflower genotypes were received from Department of Oil Crops Research, Field Crop Research Institute, Agricultural Research Center, Egypt.

2.3. Agricultural practices Sunflower genotypes seeds under study were hand-planted on ridges, 60 cm as well as 15, 20 and 25 cm apart between hills in accordance with the treatment variables. This was done on the first week of June in both seasons. Plants of sunflower genotypes under study were thinned at 15 days after sowing to secure one plants hill-1. Fertilization was added in two equal portions prior to the first and the second irrigations in the form of urea (46.6 % N) in accordance with the treatment variable the previously mentioned. All other cultural practices were applied as recommended.

2.4. Data collected 2.4.1. Yield and yield attributes Number of days to 50 % flowering as flowering date was recorded for each sub sub plots. At harvest, five guarded plants were randomly selected from the 2 nd and 4th ridges, harvested, tied and left

to head dry to determine yield and yield attributes viz. plant height in cm, stem diameter in cm, head diameter in cm, 100-seed weight in gram and seed weight plant-1 in gram. Plants of central ridge from each sub sub plots were harvested for determining seed yield per m2 and converted to recorded seed yield in kg fad-1.

2.4.2. Chemical composition of seeds Samples of seeds were oven dried, ground finely and stored in small bags for chemical analysis. Seed oil content was determined according to [7]. Seed nitrogen percentage was estimated by using micro Kjeldahl apparatus and multiplied by the converting factor (6.25) to get seed protein percentage [16]. Gas liquid chromatography (Aglent 6890 GC, USA) used for determination and identification of the fatty acids methyl esters, in Central Laboratory of Food Technology Research Institute, ARC, Egypt, according to [30].

2.5. Statistical analysis All data collected in this study of each season were analyzed as mentioned by [13]. Homogeneity of variance between two seasons was checked as described by [13]. The proper combined analysis of variance (over the two seasons) of the split split plot design was done according to [25]. Mean separation of treatment effects in this study was accomplished using the least significant difference (LSD) test and Duncan's Multiple Range Test at 5% level of probability. Combined data of the two seasons for the studied sunflower genotypes under plant spaces and nitrogen fertilization levels were employed to calculate correlation and path analysis. The coefficient of correlation between all pairs of the yield and yield attributes as well as between all pairs of seed oil content and major fatty acids composition, were computed as suggested by [25]. Finally, path coefficient analysis was done between seed weight plant-1 as a dependant variable and yield

attributes as independent variables as well as between seed oil content as a dependent variable and major fatty acids composition as independent variables i.e. oleic acid content, linoleic acid content unsaturated fatty acids as well as palmitic acid content and stearic acid content saturated fatty acids according to the method mentioned by [18].

3. RESULTS AND DISCUSSION 3.1. Yield and its attributes 3.1.1. Effect of plant spacing Regarding plant spacing, data from Table 2 revealed that there was significant increase in each of number of days to 50 % flowering, stem diameter, head diameter, 100-seed weight, seed weight plant-1 and then seed yield fad.-1 with increasing the distance between plants from 15 – 20 and up to 25 cm in both seasons and their combined analysis. Conversely, plant height was took the reverse trend with increasing distance between plants. As shown in the combined analysis, obviously, wider spacing of 25 cm gave the highest values for yield and its attributes, exceeding the narrow spacing of 15 cm by 4.81%, 4.00%, 21.44%, 7.82%, 10.39% and 4.68 % with regard to number of days to 50 % flowering, stem diameter, head diameter, 100-seed weight, seed weight plant-1 (g) and seed yield fad.-1, respectively. This may be due to the plants grown under wider spaces received more nutrients, light and moisture around each plant surrounding compared to plants in closer spaces which is probably the cause of better performance of yield and its attributes represents days to 50 % flowering, stem diameter, head diameter, 100-seed weight, seed weight plant-1 and seed yield fad.-1. These results are in parallel with those obtained by [9, 19, 17, 28, 6, 26, 15, 8 and 3] they found that plant spacing has positive effect on yield and its components except plant height responded negatively.

3.1.2. Nitrogen fertilization levels effects Data in Table 2 show that each increase in N application level from 15 to 30 then up to 45 N fad.-1 was followed by a significant increase in yield and yield attributes in both seasons and their combined analysis. This might be due to the well utilization of N supplied in the metabolism and the meristemic activity leading to the increase of plant height, which are responsible for cell division and elongation in addition to formation of the plant organs. This leads to more vigorous growth and consequently accumulation of more photosynthesis assimilates which resulted in greater head seed weight. Similar significant effects were reported by [6, 2, 8, 3 and 20].

3.1.3. Tested sunflower genotypes effect It is clear from the data in Table 2 that significant differences were detected among the three tested sunflower genotypes i.e. Giza 102, Sakha 53 and promising line of L120 with respect to yield and yield attributes in both seasons and their combined analysis. It can be observed from the combined analysis that Sakha 53 behaved as the largest stem and head diameters, the heaviest weight of 100 seed, seed plant-1 and fad.-1 followed by promising line of L120 while Giza 102 gave the lowest values of the previous traits. The differences between the tested sunflower genotypes may be due to the differences in their genetically constituents. Similar results were reported by [15, 3 and 20].

3.1.4. Dual and tripe interactions effects The interactive effect of plant spacing with nitrogen, plant spacing with sunflower genotypes, and nitrogen levels with sunflower genotypes was significant for yield and yield attributes in both seasons and their combined analysis, as shown in Table 2.

For interaction between plant spaces and nitrogen fertilization levels as pooled data in Table 2a, sunflower plants took longer days to 50 % flowering (48.94 day) as well as achieved largest stem (2.59 cm) and head diameters (24.57 cm), heaviest weight of 100-seed (5.62 cm) and seed plant-1 (75.13 g) and hence seed yield fad.-1 (1005.99 kg) at 25 cm plant spacing with nitrogen application at the level of 45 N/fad.. With respect to interaction between plant spaces and tested sunflower genotypes as combined analysis in Table 2 b, flowered late (48.61 day) and largest stem (2.56 cm) and head diameters (23.80 cm), heaviest weight of 100-seed (5.59) and seed plant-1 (75.35 g) and hence seed yield fad.-1 (1027.22 kg) were recorded when grown Sakha 53 at 25 cm plant spacing, whereas taller plants achieved by promising line of L120 sowing on 15 cm plant spacing. The longest time to 50 % flowering, and the largest stem diameter (2.62 cm) and head one (24.27 cm), heaviest weight of 100-seed (5.57 g) and seed plant-1 (73.99 g) and hence seed yield fad.-1 (1026.46) was produced with sowing sunflower Sakha 53 with increasing level of nitrogen application at (45 N/fad.), while tallest plants (189.28 cm) obtained by sowing sunflower promising line of L 120 at the same level of nitrogen application, as seen in pooled data (Table 2c) of interaction between nitrogen fertilization levels and tested sunflower genotypes. As shown in the presented pooled data in Table 2d, the triple interaction had a significant effect on yield and yield attributes in both seasons and their combined analysis. Generally, as the average in both seasons, the highest values of head diameter (25.95 cm), 100-seed weight (5.74 g), seed weight plant-1 (81.05 g) and hence seed yield fad.-1 (1071.68 kg) were obtained by grown sunflower cv Sakha 53 at wider spacing of 25 cm with application of nitrogen fertilization at level of 45 N fad.-1 followed by promising line of L120 at the same conditions.

3.2. Chemical composition of seeds 3.2.1. Plant spacing effects It is apparent from the data given in Table 3, a significant effect of plant spacing was observed on proportion of oil, protein, palmitic acid, stearic acid, oleic acid and linoleic acid. In particular, a progressive increase was observed in seed protein content (%) by 3.89 and 8.69 %, oleic acid content (%) by 1.81 and 3.55 % and linoleic acid content (%) by 0.96 and 2.67 % and a corresponding decrease was found in seed oil content (%), palmitic acid content (%) by 20.08 and 48.76 % and stearic acid content (%) by 25.76 and 107.50 % with increasing plant spacing from 15 to 20 cm and up to 25 cm, in respective order. It is worth noting that grown plants with wider spacing of 25 cm led to obtain larger proportion of oleic and linoleic unsaturated fatty acids as presented in Table 3 and leading to obtain the highest seed yield fad.-1 as presented in Table 2. Accordingly, grown plants at wider spacing of 25 cm is a good compromise as it allows both higher seed yield fad.-1 and better acids composition of oil. Significant effect of plant spacing on chemical composition of seeds has been reported by [15 and 10].

3.2.2. Nitrogen fertilization levels effects It is clear from the data presented in Table 3 that increase nitrogen fertilization levels application from 15 N fad.-1 up to 45 N/fad., as seen in the combined analysis, was associated with a significant increase in seed protein content by 6.70 %, proportion of oleic acid by 2.51 % and linoleic acid by 1.94%, and corresponding decrease in seed oil content by 3.74 %, proportion of palmitic acid by 62.30 and stearic acid by 126.32 %, indicating that increasing nitrogen fertilization level reflected on good quality of sunflower oil. The positive effect of nitrogen fertilization application was recorded by [4] observed that increasing nitrogen levels resulted in steady increases in yield, protein contents and linoleic acid, whereas, oil content and percentage of oleic acid responded negatively.

3.2.3. Tested sunflower genotypes effects

Table 2- Effect of plant spaces, nitrogen fertilization levels on yield and yield attributes of tested sunflower genotypes in 2013 and 2014 summer seasons and their combined analysis Main effects Days to 50 % and Plant height (cm) Stem diameter (cm) Head diameter (cm) 100-seed weight (g) Seed weight plant-1 (g) Seed yield/fad. (kg) flowering (day) interactions 1st 2nd Com. 1st 2nd Com. 1st 2nd Com. 1st 2nd Com. 1st 2nd Com. 1st 2nd Com. 1st 2nd Com. S1: 15 cm S2: 20 cm S3:25 cm LSD 5%

45.52c 46.81b 48.04a 0.38

43.96b 44.70b 45.96a 0.89

44.74c 45.76b 47.00a 0.54

178.12a 177.90a 174.56b 1.03

173.91a 173.81a 170.48b 0.89

176.02a 175.86a 172.52b 0.94

2.57c 2.62b 2.68a 0.03

2.23b 2.27b 2.33a 0.05

N1:15 N fad. N2:30 N/fad. N3:45 N/fad. LSD 5%

45.11c 46.85b 48.41a 0.49

42.93c 45.19b 46.52a 0.61

44.02c 46.02b 47.46a 0.53

175.45b 175.83b 179.30a 1.46

171.25b 171.71b 175.25a 1.41

173.35b 173.77b 177.28a 1.42

2.45c 2.67b 2.74a 0.03

2.11c 2.33b 2.40a 0.04

G1:Giza 102 G2:Sakha 53 G3: L 120 LSD 5%

44.59c 48.22a 47.56b 0.35

42.67c 46.30a 45.67b 0.35

43.63c 47.26a 46.61b 0.35

161.33c 180.91b 188.35a 1.49

157.13c 176.82b 184.26a 1.55

159.23c 178.86b 186.30a 1.51

2.51c 2.71a 2.64b 0.03

2.16c 2.37a 2.30b 0.03

SN SG NG SNG

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

Plant spacing (S) 2.40b 18.72c 17.34c 2.44b 22.00b 20.69b 2.50a 23.65a 22.26a 0.04 1.38 1.33 Nitrogen levels (N) 2.28c 19.60c 18.24c 2.50b 21.50b 20.18b 2.57a 23.26a 21.86a 0.03 0.64 0.68 Genotypes(G) 2.33c 19.86c 18.42c 2.54a 22.59a 21.30a 2.47b 21.92b 20.58b 0.03 0.52 0.57 Interaction * * * * * * * * * * * *

18.03c 21.35b 22.95a 1.35

5.20c 5.46b 5.63a 0.07

4.94c 5.20b 5.37a 0.07

5.07c 5.33b 5.50a 0.07

66.39c 70.58b 73.97a 1.30

62.76c 66.83b 70.15a 1.41

64.57c 68.70b 72.06a 1.33

936.49c 964.56b 981.88a 9.97

929.36c 957.20b 975.58a 12.27

932.93c 960.88b 978.73a 11.06

18.92c 20.84b 22.56a 0.66

5.19c 5.48b 5.63a 0.07

4.93c 5.21b 5.37a 0.07

5.06c 5.35b 5.50a 0.07

66.88c 71.18b 72.88a 1.41

63.20c 67.42b 69.12a 1.62

65.04c 69.30b 71.00a 1.50

935.17c 963.85b 983.91a 5.22

928.37c 956.79b 977.00a 5.29

931.77c 960.32b 980.46a 5.21

19.14c 21.94a 21.25b 0.53

5.35b 5.58a 5.36b 0.06

5.09b 5.32a 5.11b 0.07

5.22b 5.45a 5.24b 0.07

66.56c 74.23a 70.15b 1.16

62.89c 70.41a 66.44b 1.24

64.72c 72.32a 68.30b 1.19

902.44c 1001.03a 979.46b 6.39

895.90c 993.75a 972.50b 6.04

899.17c 997.39a 975.98b 6.17

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

1st, 2nd and com., = first season, second season and combined analysis, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Table 2a- Effect of interaction between plant spaces and nitrogen fertilization levels on yield and its attributes (combined data of 20 13 and 2014 summer seasons) Traits

S.N. S1N1 S1N2 S1N3 S2N1 S2N2 S2N3 S3N1 S3N2 S3N3 LSD 5% SiNi-Si Nj SiNi-Sj Ni

Days to 50 % flowering (day) 42.11d 45.44c 46.67b 44.83c 45.67c 46.78b 45.11c 46.94b 48.94a 0.925 0.866

Plant height (cm)

Stem diameter (cm)

Head diameter (cm)

100-seed weight (g)

Seed weight plant-1 (g)

Seed yield fad.-1 (kg)

176.38ab 173.39cd 178.28a 174.83bcd 175.39bc 177.35ab 168.84e 172.53d 176.20ab

2.20f 2.44c 2.55ab 2.27e 2.51b 2.55ab 2.37d 2.54ab 2.59a

15.26f 18.50e 20.34cd 20.01d 21.25c 22.78b 21.50c 22.79b 24.57a

4.67d 5.13c 5.40b 5.09c 5.42b 5.48b 5.40b 5.49b 5.62a

58.80f 67.31de 67.62cde 66.69e 69.16bcde 70.26bc 69.63bcd 71.44b 75.13a

898.14e 943.42d 957.22c 943.45d 961.04c 978.16b 953.71c 976.51b 1005.99a

2.464 2.141

0.057 0.055

1.142 1.413

0.120 0.113

2.603 2.368

9.024 11.388

S and N= Plant spaces and nitrogen fertilization levels, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Table 2 b- Effect of interaction between plant spaces and tested sunflower genotypes (combined data of 2013 and 2014 summer seasons) Traits Days to 50 % Stem Head 100-seed Seed yield Plant Seed weight flowering diameter diameter weight fad.-1 height (cm) plant-1 (g) (day) (cm) (cm) (g) (kg) S.G. S1G1 S1G2 S1G3 S2G1 S2G2 S2G3 S3G1 S3G2 S3G3 LSD 5% SiGi-Si Gj SiGi-Sj Gi

42.22g 46.33c 45.67d 43.94f 46.83c 46.50c 44.72e 48.61a 47.67b

161.16e 177.88d 189.01a 159.51ef 182.05c 186.01b 157.02f 176.67d 183.89bc

2.25f 2.53ab 2.42d 2.32e 2.54ab 2.48c 2.43d 2.56a 2.51bc

16.33d 18.93c 18.84c 23.11a 21.98b 22.13b 23.80a 22.93ab

5.02d 5.26c 4.92d 5.22c 5.49ab 5.29c 5.42b 5.59a 5.50ab

60.18e 69.51c 64.04d 64.27d 72.11b 69.73c 69.72c 75.35a 71.12ab

882.64g 966.71d 949.43e 903.49f 998.25b 980.91c 911.37f 1027.22a 997.61b

0.600 0.628

2.614 2.241

0.045 0.046

0.912 1.238

0.116 0.108

2.061 1.943

10.691 11.896

18.95c

S and G= Plant spaces and tested sunflower genotypes, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Table 2 c- Effect of interaction between summer seasons) Traits Days to 50 % flowering (day) N.G. N1G1 N1G2 N1G3 N2G1 N2G2 N2G3 N3G1 N3G2 N3G3 LSD 5% NiGi-Ni Gj NiGi-Nj Gi

nitrogen fertilization levels and tested sunflower genotypes (combined data of 2013 and 2014 Plant height (cm)

Stem diameter (cm)

Head diameter (cm)

100-seed weight (g)

Seed weight plant-1 (g)

Seed yield fad.-1 (kg)

42.44f 44.33e 45.28d 43.94e 47.61b 46.50c 44.50e 49.83a 48.06b

156.29f 179.36c 184.41b 160.26e 175.83d 185.23b 161.14e 181.40c 189.28a

2.06f 2.44d 2.34e 2.43d 2.56b 2.50c 2.51c 2.62a 2.58ab

18.01e 19.21d 19.55d 18.90de 22.35b 21.28c 20.51c 24.27a 22.91b

4.87d 5.31b 4.99c 5.31b 5.46a 5.27b 5.48a 5.57a 5.46a

60.94e 68.38c 65.78d 64.85d 74.59a 68.47c 68.38c 73.99a 70.64b

865.29g 969.87cd 960.14d 908.82f 995.84b 976.30c 923.39e 1026.46a 991.52b

0.600 0.494

2.614 1.776

0.045 0.034

0.912 0.682

0.116 0.081

2.061 1.547

10.691 7.061

N and G= nitrogen fertilization levels and tested sunflower genotypes, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Table 2d- Effect of triple interaction among plant spaces, 2013 and 2014 summer seasons) Traits Days to 50 % Plant flowering height (cm) (day) S.N.G. S1N1G1 39.33j 157.31ij S1N1G2 43.33i 182.37cd hi S1N1G3 43.67 189.47a i S1N2G1 43.33 162.43hi S1N2G2 46.67cde 170.53g S1N2G3 46.33cde 187.21abc S1N3G1 44.00hi 163.73h S1N3G2 49.00b 180.73de S1N3G3 47.00cd 190.37a hi S2N1G1 43.83 158.30i fgh S2N1G2 44.83 182.23cd S2N1G3 45.83def 183.97bcd S2N2G1 44.00hi 159.80hi S2N2G2 46.67cde 180.13de S2N2G3 46.33cde 186.23abc S2N3G1 44.00hi 160.43hi b S2N3G2 49.00 183.78bcd c S2N3G3 47.33 187.83ab S3N1G1 44.17hi 153.25j S3N1G2 44.83fgh 173.47fg S3N1G3 46.33cde 179.80de S3N2G1 44.50ghi 158.53i S3N2G2 49.50b 176.83ef cd S3N2G3 46.83 182.23cd efg S3N3G1 45.50 159.27hi S3N3G2 51.50a 179.70de S3N3G3 49.83b 189.63a LSD 5% SiNi Gi-Si Ni Gj 1.039 4.527 SiNi Gi-Si Nj Gi 1.209 4.350 SiNi Gi-Sj Ni Gi 1.170 4.200

nitrogen fertilization levels and tested sunflower genotypes (combined data of Stem diameter (cm)

Head diameter (cm)

100-seed weight (g)

Seed weight plant-1 (g)

Seed yield fad.-1 (kg)

2.00j 2.36gh 2.25i 2.33h 2.56bc 2.43efg 2.42fg 2.66a 2.59abc 1.98j 2.47def 2.36gh 2.46def 2.56bc 2.53bcd 2.53bcd 2.59abc 2.54bcd 2.21i 2.51cde 2.40fgh 2.52bcd 2.58abc 2.53bcd 2.57bc 2.60abc 2.61ab

15.30mn 14.13n 16.36lm 15.57mn 20.69ghij 19.24ijk 18.14k 21.96defg 20.93fghi 17.84kl 21.68efgh 20.52ghij 19.00jk 22.74cdef 22.01defg 20.03hij 24.91ab 23.40bcde 20.90fghi 21.81defgh 21.79defgh 22.13defg 23.64bcd 22.60def 23.36bcde 25.95a 24.39abc

4.38i 5.05fg 4.59h 5.21ef 5.27de 4.92g 5.47bcd 5.47bcd 5.26def 4.91g 5.40bcde 4.97g 5.31cde 5.55abc 5.39bcde 5.43bcde 5.50bcd 5.52abc 5.31cde 5.48bcd 5.41bcde 5.43bcde 5.55abc 5.49bcd 5.53abc 5.74a 5.60ab

53.82m 63.99ijk 58.58l 61.48jkl 74.35bc 66.10ghi 65.24hij 70.19defg 67.43fghi 60.72kl 70.56cdef 68.79defgh 63.94ijk 75.03b 68.52defgh 68.15efgh 70.74cdef 71.90bcde 68.29efgh 70.60cdef 69.99defg 69.14defgh 74.39bc 70.78cdef 71.74bcde 81.05a 72.60bcd

830.03k 934.62g 929.77gh 898.71ij 976.78cde 954.77f 919.19gh 988.73cd 963.74ef 880.11j 981.43cde 968.82def 909.97hi 994.35c 978.79cde 920.40gh 1018.97b 995.12c 885.74j 993.57c 981.81cde 917.79ghi 1016.40b 995.33c 930.58gh 1071.68a 1015.69b

0.077 0.082 0.081

1.580 1.671 1.842

0.201 0.199 0.195

3.569 3.790 3.654

18.517 17.295 18.464

S, N, G= Plant spaces, nitrogen fertilization levels and tested sunflower genotypes, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

As shown in the Table 3 sunflower genotypes significantly differed in all chemical composition of sunflower seeds characters in both seasons and their combined analysis. Sakha 53 was superior in seed oil content followed by promising line of L120 compared to Giza 102 recorded lowest values while the good oil quality was in favor of the latter with its contained the highest proportion from oleic acid and linoleic acid unsaturated fatty acid followed by Sakha 53 in the previous two acids mentioned. These findings are in accordance with those obtained by [15].

3.2.4. Dual and triple interactions The interactive effect of plant spacing with nitrogen, plant spacing with sunflower genotypes, and nitrogen levels with sunflower genotypes was significant for all chemical composition of seeds in both seasons and their combined analysis, as per the data in Table 3. As shown in Table 3a, chemical composition of seeds have the highest proportion of oil with combination between sowing on closer spacing of 15 cm and nitrogen fertilization application at the level of 15 N fad.-1 with respect to interaction between plant spaces and nitrogen fertilization levels. However, the highest proportion of oleic acid and linoleic acid content were achieved by sowing at wider spacing of 25 cm with increasing nitrogen fertilization level application up to 45 N fad.-1. Concerning interaction between plant spaces and tested sunflower genotypes, the maximum percentage of seed oil content was obtained by grown sunflower cv Giza 102 at closer plant spacing of

15 cm. Moreover, the highest proportion of oleic and linoleic unsaturated fatty acids composition was achieved by grown sunflower local cultivar Giza 102 at wider spacing, as pooled analysis in Table 3 b. In case of interaction between nitrogen fertilization and tested sunflower genotypes as the average in both seasons in Table 3 c, the highest content of oil in seed was achieved by combination between grown Sakha 53 and addition the lowest level of nitrogen fertilization, while the highest mean of protein content, oleic acid content and linoleic unsaturated fatty acids was created by grown Giza 102 with increasing nitrogen fertilization level up to 45 N fad.-1. Finally, for triple interaction between three factors under study, the pooled data of both seasons presented in Table 3d, revealed that the highest proportion of oil in seed was achieved by combination of grown Sakha 53 at narrow spacing of 15 cm with adding nitrogen fertilization at the lowest level of 15 N fad.-1, while better oil quality represented the highest proportion from oleic and linoleic unsaturated fatty acids have been achieved by sowing the same cultivar previously mentioned at wider spacing of 25 cm with increasing nitrogen levels up to 45 N fad.-1.

3.3. Yield analysis 3.3.1. Correlation The matrix of simple correlation among seed weight plant -1 and its related characters over the two seasons (n=162) is presented in Table 4.

Table 3- Effect of plant spaces, nitrogen fertilization levels on seeds chemical composition of tested sunflower genotypes in 2013 and 2014 summer seasons and their combined analysis Main effects Seed protein content Palmatic acid Stearic acid content Linoleic acid content and Seed oil content (%) Oleic acid content (%) (%) content (%) (%) (%) interactions 1st

2nd

Com.

1st

2nd

Com.

S1: 15 cm S2: 20 cm S3:25 cm LSD 5%

38.33a 38.09b 37.61c 0.14

38.25a 38.01b 37.54c 0.17

38.29a 38.05b 37.58c 0.14

19.14c 19.78b 20.87a 0.48

18.91c 19.82b 20.81a 0.56

19.03c 19.80b 20.84a 0.49

N1:15 N/fad. N2:30 N/fad. N3:45 N/fad. LSD 5%

38.60a 38.22b 37.22c 0.09

38.53a 38.16b 37.11c 0.08

38.56a 38.19b 37.17c 0.08

19.28c 19.93b 20.59a 0.21

19.15c 19.80b 20.59a 0.16

19.21c 19.86b 20.59a 0.16

G1:Giza 102 G2:Sakha 53 G3: L 120 LSD 5%

37.00c 38.98a 38.06b 0.05a

36.93c 38.90a 37.98b 0.06

36.96c 38.94a 38.02b 0.04

20.70a 19.05c 20.04b 0.17

20.67a 18.92c 19.95b 0.21

20.68a 18.99c 19.99b 0.16

SN SG NG SNG

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

1st

2nd Com. 1st Plant spacing (S) 3.01a 2.97a 2.99a 0.85a 2.49b 2.48b 2.49b 0.67b c c c 2.04 1.98 2.01 0.41c 0.06 0.15 0.09 0.03 Nitrogen levels (N) 2.98a 2.95a 2.97a 0.88a 2.71b 2.67b 2.69b 0.66b 1.85c 1.81c 1.83c 0.39c 0.05 0.07 0.05 0.04 Genotypes (G) 3.28a 3.25a 3.26a 0.35c 2.52b 2.48b 2.50b 0.97a 1.74c 1.71c 1.72c 0.61b 0.05 0.06 0.05 0.04 Interaction * * * * * * * * * * * * * * * *

2nd

Com.

1st

2nd

Com.

1st

2nd

Com.

0.81a 0.65b 0.39c 0.06

0.83a 0.66b 0.40c 0.03

46.41c 47.02b 47.80a 0.17

46.00c 47.09b 48.02a 0.31

46.21c 47.06b 47.91a 0.21

43.35c 43.83b 44.69a 0.27

43.50c 43.87b 44.72a 0.48

43.43c 43.85b 44.62a 0.21

0.84a 0.64b 0.36c 0.05

0.86a 0.65b 0.38c 0.04

46.51c 46.96b 47.76a 0.20

46.60c 46.74b 47.76a 0.26

46.56c 46.85b 47.76a 0.20

43.56c 43.92b 44.39a 0.18

43.52c 44.07b 44.51a 0.22

43.54c 43.95b 44.40a 0.16

0.33c 0.93a 0.58b 0.05

0.34c 0.95a 0.60b 0.04

49.98a 46.03b 45.23c 0.15

49.92a 46.03b 45.16c 0.19

49.95a 46.03b 45.20c 0.14

46.95a 42.93b 41.99c 0.18

47.00a 43.00b 42.09c 0.20

46.97a 43.00b 41.92c 0.21

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

* * * *

1st, 2nd and com. = first season, second season and combined analysis, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Table 3 a- Effect interaction between plant spaces and nitrogen fertilization levels on chemical composition of seeds (combined data of 2013 and 2014 summer seasons) Traits

S.N. S1N1 S1N2 S1N3 S2N1 S2N2 S2N3 S3N1 S3N2 S3N3 LSD 5% SiNi-Si Nj SiNi-Sj Ni

Seed oil content (%)

Seed protein content (%)

Palmatic acid content (%)

Stearic acid content (%)

Oleic acid content (%)

Linoleic acid content (%)

38.84a 38.42bc 37.61f 38.53b 38.27d 37.36g 38.33cd 37.88e 36.52h

18.19a 19.04f 19.86de 19.31f 19.81e 20.28c 20.14cd 20.75b 21.63a

3.41a 3.17b 2.39e 2.88c 2.64d 1.94g 2.62d 2.26f 1.15h

1.28a 0.68b 0.53e 0.75c 0.91d 0.31g 0.54d 0.36f 0.29h

45.81f 45.85f 46.96de 46.61e 47.06d 47.50bc 47.26cd 47.66b 48.83a

42.93e 43.43d 43.92c 43.51d 43.98c 44.07c 44.17c 44.46b 45.22a

0.139 0.160

0.281 0.447

0.094 0.107

0.076 0.067

0.351 0.330

0.271 0.277

S and N= Plant spaces and nitrogen fertilization levels, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Table 3 b- Effect of interaction between plant 2013 and 2014 summer seasons) Traits Seed oil content (%) S.G. S1G1 37.22g S1G2 39.25a S1G3 38.40d S2G1 37.06h S2G2 38.99b S2G3 38.10e S3G1 36.61i S3G2 38.56c S3G3 37.56f LSD 5% SiGi-Si Gj 0.075 SiGi-Sj Gi 0.121

spaces and tested sunflower genotypes on chemical composition of seeds (combined data of

Seed protein content (%)

Palmatic acid content (%)

Stearic acid content (%)

Oleic acid content (%)

Linoleic acid content (%)

19.62d 18.32f 19.14e 20.66c 18.90e 19.83d 21.76a 19.74d 21.01b

3.96a 2.87c 2.14e 3.27b 2.48d 1.71f 2.57d 2.15e 1.32g

0.54e 1.19a 0.75c 0.24g 1.10b 0.64d 0.25g 0.56e 0.39f

48.67c 45.42f 44.53g 50.20b 45.73e 45.24f 50.98a 46.94d 45.83e

46.01c 42.50e 41.78f 47.01b 42.61e 41.93f 47.90a 43.88d 42.06f

0.269 0.419

0.091 0.102

0.071 0.063

0.242 0.250

0.358 0.331

S and G= Plant spaces and tested sunflower genotypes, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Table 3 c- Effect of interaction between nitrogen fertilization and tested sunflower genotypes on chemical composition of seeds (combined data of 2013 and 2014 seasons) Traits Seed oil Seed protein Palmatic acid Stearic acid Oleic acid Linoleic acid content (%) content (%) content (%) content (%) content (%) content (%) N.G. N1G1 N1G2 N1G3 N2G1 N2G2 N2G3 N3G1 N3G2 N3G3 LSD 5% NiGi-Ni Gj NiGi-Nj Gi

37.54e 39.46a 38.70c 37.18f 39.19b 38.20d 36.17g 38.16d 37.17f

19.94c 18.34f 19.37d 20.87b 18.76e 19.96c 21.25a 19.86c 20.65b

3.77a 3.06c 2.07f 3.51b 2.67d 1.89g 2.51e 1.76h 1.22i

0.48c 1.19a 0.91b 0.31de 1.14a 0.51c 0.24e 0.53c 0.36d

49.45c 45.36f 44.86g 49.80b 45.74e 45.02g 50.60a 46.97d 45.72e

46.43c 42.38f 41.80g 47.04b 42.88e 41.94g 47.45a 43.73d 42.03fg

0.075 0.068

0.269 0.188

0.091 0.064

0.071 0.050

0.242 0.193

0.358 0.231

N and G= nitrogen fertilization levels and tested sunflower genotypes, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Table 3d- Effect of triple interaction among plant spaces, nitrogen fertilization levels and tested sunflower genotypes on chemical composition of seeds (combined data of 2013 and 2014 summer seasons) Traits

Seed oil content (%)

S.N.G S1N1G1 S1N1G2 S1N1G3 S1N2G1 S1N2G2 S1N2G3 S1N3G1 S1N3G2 S1N3G3 S2N1G1 S2N1G2 S2N1G3 S2N2G1 S2N2G2 S2N2G3 S2N3G1 S2N3G2 S2N3G3 S3N1G1 S3N1G2 S3N1G3 S3N2G1 S3N2G2 S3N2G3 S3N3G1 S3N3G2 S3N3G3 LSD 5% SiNi Gi-Si Ni Gj SiNi Gi-Si Nj Gi SiNi Gi-Sj Ni Gi

Seed protein content (%)

Palmatic acid content (%)

Stearic acid content (%)

Oleic acid content (%)

Linoleic acid content (%)

37.87h 39.72a 38.93d 37.30l 39.42b 38.55ef 36.49n 38.62e 37.73i 37.47jk 39.43b 38.68e 37.30l 39.23c 38.27g 36.40n 38.31g 37.36kl 37.27l 39.24c 38.47f 36.95m 38.91d 37.77hi 35.61o 37.55j 36.42n

18.47m 17.49n 18.61m 19.98ghi 17.92n 19.21kl 20.42defg 19.56ijk 19.59ijk 20.13fgh 18.44m 19.38jk 20.82bcde 18.82lm 19.78hij 21.04bc 19.45jk 20.35efg 21.21b 19.10kl 20.13fgh 21.80a 19.55ijk 20.90bcd 22.28a 20.59cdef 22.01a

4.39a 3.45d 2.39h 4.22b 2.95fg 2.34hi 3.28e 2.20ij 1.69k 3.69c 2.85fg 2.09j 3.31de 2.78g 1.84k 2.80g 1.82k 1.21m 3.24e 2.89fg 1.73k 3.02f 2.29hi 1.49l 1.45l 1.27m 0.74n

0.85d 1.60a 1.38b 0.31jkl 1.33b 0.41fghij 0.47fghi 0.64e 0.47fghi 0.24lmn 1.17c 0.85d 0.34hijkl 1.59a 0.80d 0.14mn 0.54ef 0.26klm 0.35hijkl 0.79d 0.50fg 0.27jklm 0.48fgh 0.33ijkl 0.12n 0.40fghijk 0.36ghijkl

48.20e 44.80klm 44.41mn 48.42e 45.11jkl 44.01n 49.38d 46.34f 45.16ijk 49.66d 45.50hij 44.67lm 50.22c 45.59hi 45.35hij 50.72b 46.09fg 45.69gh 50.49bc 45.79gh 45.48hij 50.75b 46.53f 45.70gh 51.70a 48.48e 46.30f

45.44d 41.90hijk 41.46k 46.20c 42.52fgh 41.57k 46.39c 43.08ef 42.30ghij 46.51c 42.39fghi 41.63jk 47.18b 42.59fgh 42.16ghijk 47.35b 42.83fg 42.01hijk 47.35b 42.85fg 42.31ghij 47.76b 43.53e 42.09hijk 48.61a 45.27d 41.79ijk

0.130 0.183 0.168

0.465 0.563 0.461

0.158 0.163 0.156

0.123 0.118 0.123

0.419 0.460 0.473

0.621 0.568 0.566

S, N, G= Plant spaces, nitrogen fertilization levels and tested sunflower genotypes, respectively Means followed by the same letter are not significantly different from one another based on Duncan's multiple test at 5%

Results showed that the most important relationships to sunflower breeder were those between seed weight plant-1 and each of head diameter (r=0.871**), 100-seed weight (r=0.847**), days to 50 % flowering (r=0.831**), stem diameter (r=0.789**) and plant height (r=0.314**).

It is evident that the selection for the previous traits would improve the productivity of sunflower due to their positive and highly significant association with seed weight plant-1. On the other hand, yield components appeared positive and highly significant associations among themselves except between plant height and 100seed weight was positive and insignificant.

Table 4- The matrix of simple correlation coefficients among seed weight plant-1 and yield attributes (over treatments and seasons of 2013 and 2014) Seed Days to 50% Stem Head 100-seed Traits Plant height weight flowering diameter diameter weight plant-1 Days to 50% flowering

1.000

Plant height

0.570**

1.000

Stem diameter

0.746**

0.441**

1.000

Head diameter

0.824**

0.302**

0.717**

1.000

100-seed weight

0.691**

0.108

0.796**

0.786**

1.000

Seed yield/plant

0.831**

0.314**

0.789**

0.871**

0.847**

3.3.2. Path analysis and relative importance Information obtained from correlation coefficients can be augmented by partitioning the correlation coefficients into direct and indirect effects for a given set of causal interrelationships. In such situations, the correlation coefficients may be confounded with indirect effects due to common inherent in trait interrelationships. So,

1.000

path coefficient analysis has proven useful in providing additional information that describes the casual relationships such as yield and its attributes. In the present investigation, the resultant variable was seed weight plant-1 while the remaining traits represented the casual variables. The matrix of direct and joint effects for the five yield-related traits on seed weight plant-1 is shown in Table 5.

The maximum direct effect were observed for 100-seed weight being 0.3194 followed by head diameter being 0.3176 and days to 50 % flowering being 0.2830. The high positive direct effects of the previous three traits in addition to their highly significant positive coefficient of correlation proved the direct selection for seed weight plant-1 through these three traits would be effective to improve the productivity of sunflower yield. In contrast, although significant correlation coefficients were recorded between seed weight plant-1 and each of plant height and stem diameter, their direct effects were negligible. On the other hand, the highest indirect effect of stem diameter on seed weight plant-1 via 100-seed weight was positive being 0.254 followed by indirect effect of head diameter via 100- seed weight being 0.2511 were observed. The coefficient of determination (CD) and relative importance (RI %) for the yield attributes of sunflower are listed in Table 6. The results

revealed that the greatest parts of seed weight plant-1 variation were explained by the direct effect for 100-seed weight being 9.8707 % , followed by head diameter being 9.7605 and days to 50 % flowering being 7.7495%. The considerable contribution of the three traits on sunflower yield proves they may be used as selection criteria in sunflower breeding program. However, the other characters recorded small or negligible direct effects upon seed weight plant-1. Regarding the relative importance of joint effects components, considerable parts of indirect effects were obtained by head diameter on seed weight plant-1 through its association with 100-seed weight being 15.4298 % followed by days to 50 % flowering via head diameter being 14.3328 %. Totally, the studied traits explained 86.3483 % of seed weight plant-1 variation. Accordingly, the residual effect of other seed yield attributes was 13.6517 % of the total seed weight plant-1 variation.

Table 5- The direct and joint effects of predictor characters on seed weight plant-1 (combined data over treatments and the two seasons of 2013 and 2014)

Traits

Days to 50% flowering

Plant height

Stem diameter

Head diameter

100-seed weight

Correlation

Days to 50% flowering

0.2830

-0.0142

0.0797

0.2617

0.2207

0.8310**

Plant height

0.1613

-0.0249

0.0471

0.0959

0.0345

0.3140**

Stem diameter

0.2111

-0.0110

0.1068

0.2277

0.2543

0.7890**

Head diameter

0.2332

-0.0075

0.0766

0.3176

0.2511

0.8710**

100-seed weight

0.1956

-0.0027

0.0850

0.2497

0.3194

0.8470**

Residual

0.3757

Table 6- The coefficient of determination (CD) and relative importance (RI%) for yield attributes in sunflower over treatments and the two seasons of 2013 and 2014 Character

CD

Contribution %

RI%

Direct effects Days to 50% flowering (X1)

0.0801

8.0106

7.7495

Plant height

(X2)

0.0006

0.0618

0.0598

Stem diameter

(X3)

0.0114

1.1409

1.1037

Head diameter

(X4)

0.1009

10.0893

9.7605

100-seed weight

(X5)

0.1020

10.2032

9.8707

29.5058

28.5441

Total (direct)

0.2951

Indirect effects X1

X2

X3

Via

X2

-0.0080

-0.8020

0.7758

X3

0.0451

4.5105

4.3635

X4

0.1482

14.8156

14.3328

X5

0.1249

12.4942

12.0870

X3

-0.0023

-0.2342

0.2265

X4

-0.0048

-0.4769

0.4613

X5

-0.0017

-0.1715

0.1659

X4

0.0487

4.8653

4.7067

X5

0.0543

5.4317

5.2547

X5

0.1595

15.9497

15.4298

Indirect total (absolute)

0.5975

59.7515

57.8041

Total (direct + indirect)

0.8926

89.2574

86.3483

Residuals

0.1411

14.1117

13.6517

Absolute total

1.0337

103.3690

100.0000

Via

Via

X4

3.4. Relationships between seed oil content and its contents of major fatty acids composition 3.4.1. Correlation General correlations between seed oil content and major fatty acids are presented in Table 7. Positive and highly significant association

was observed between seed oil content and proportion of stearic acid saturated fatty acid as well as positive and non significant between seed oil content and proportion of palmatic acid saturated fatty acid. On the other hand, negative and highly significant correlation was observed between seed oil content and proportion of oleic acid (r=0.768**) and linoleic acid unsaturated fatty acids (-0.699**). Moreover, major fatty acids composition exhibited various trend of association

among themselves. However, highly significant positive correlation of proportion of oleic acid with linoleic acid unsaturated fatty acids, while a highly significant negative associations of proportion of stearic acid saturated fatty acid with oleic acid content (r=-0.597**)

and linoleic acid unsaturated fatty acid (r=-0.543**) and proportion of palmatic acid with stearic acid content (r=0.230**), oleic acid content (r=0.312**) and linoleic acid content (r=0.422*).

Table 7- Correlation matrix of seed oil content and major fatty acids compositions (combined data over the treatments and the two seasons 2013 and 2014) Traits

Palmitic acid

Stearic acid

Palmitic acid

1.000

Stearic acid

0.230**

1.000

Oleic acid

Linoleic acid

Oleic acid

0.312**

-0.597**

1.000

Linoleic acid

0.422**

-0.543**

0.984**

1.000

Seed oil content

0.144

0.799**

-0.768**

-0.699**

Seed oil content

1.000

3.4.2. Path analysis and relative importance

The coefficient of determination and relative importance according to path analysis for seed oil content and major fatty acids composition are In order to find out a clear picture of the interrelationship shown in Table 9. The greatest direct effect was about 30.8876 % for between seed oil content and major fatty acids composition, direct oleic acid content followed by 8.4869 % for linoleic acid content. There and indirect effects were worked out using path analysis. Seed oil was also indirect effect of oleic acid content via linoleic acid content content was considered a dependent variable and proportion of oleic being 31.8634 %. Totally, the studied characters accounted for 96.3314 acid, linoleic acid, palmatic acid and stearic acid were independent % of seed oil content variability. The residual content being 3.6686 % variable. The estimates of direct and indirect effects estimated from may be attributed to unknown variation (random error), and/or some general correlation have been presented in Table8. Maximum direct other traits that were not under consideration in the present effect was observed for linoleic acid content being 0.6467 and also investigation. Accordingly, oleic acid content and linoleic acid content highly positive indirect effect of oleic acid content through its had the highest direct and indirect effect on seed oil content indicating association with linoleic acid content (0.6364). their importance as selection criteria to improve quantity and quality of sunflower oil. Table 8- Path coefficients (direct and joint effects) of seed oil content and fatty acids compositions (combined data over the treatme nts and the two seasons of 2013 and 2014) Traits

Oleic acid

Linoleic acid

Palmitic acid

Stearic acid

correlation

Oleic acid

-1.2338

0.6364

0.0530

-0.2236

-0.7680**

Linoleic acid

-1.2141

0.6467

0.0717

-0.2034

-0.6990**

Palmtic acid

-0.3849

0.2729

0.1699

0.0861

0.1440

Stearic acid

0.7366

-0.3512

0.0391

0.3745

0.7990**

Residual

0.4252

Table 9- The coefficient of determination (CD) and relative importance (RI %) according to path analysis of seed oil content and major fatty acids compositions (combined data over the treatments and the two seasons of 2013 and 2014) Traits CD Contribution % RI% Oleic acid Linoleic acid Palmatic acid Stearic acid Total(direct) X1

Via

X2

Via

X3

(X1) (X2) (X3) (X4)

Via Indirect total (absolute) Total (direct + indirect) Residuals Absolute total

1.5223 0.4183 0.0289 0.1403 2.1097 X2 X3 X4 X3 X4 X4

4. Conclusion Finally, it could be concluded from the current investigation that wider plant spacing, increasing nitrogen fertilization levels in addition to cultivars with high yield potential increases plant's ability to take the needs of nutrients and solar radiation, this leads to an

-1.5704 -0.1308 0.5517 0.0927 -0.2631 0.0293 2.6379 4.7476 0.1808 4.9284

Direct effects 152.2264 41.8271 2.8859 14.0271 210.9665 Indirect effects -157.0359 -13.0790 55.1738 9.2729 -26.3052 2.9268 263.7935 474.7600 18.0801 492.8401

30.8876 8.4869 0.5856 2.8462 42.8063 31.8634 2.6538 11.1951 1.8815 5.3375 0.5939 53.5252 96.3314 3.6686 100.0000

increase in photosynthesis, which reflected the increasing economic yield. Thus it could be recommended by sowing sunflower cv. Sakha 53 at wider spacing of 25 cm with application nitrogen fertilization at the level of 45 N/fad. followed by promising line of L 120 in East Delta, Egypt. This study also indicated that the importance of selection for 100-seed weight and head diameter to their direct and indirect

impact on seed weight plant-1. Also, it is important to point out the selection for oleic acid and linoleic acid content unsaturated fatty acids increases good oil quality and quantity of sunflower oil to their direct and indirect impact on quality and quantity. REFERENCES

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