Achene Yield and Quality Response of Sunflower Hybrids to Nitrogen at Varying Planting Densities Amjed. Ali, Ashfaq. Ahmad, Tasneem Khaliq, Muhammad Afzal and Zafar Iqbal Abstract The Experiment was conducted to investigate the impact of nitrogen rates on growth, yield and quality of two sunflower hybrids under varying planting densities at Faisalabad during spring season, 2010.The treatments comprised of two hybrids (Hysun-33 and S-278), three planting densities (83,333, 66,666 and 55,555 plants ha -1 by maintaining plant to plant distance 20, 25 and 30cm, respectively), with three rates of nitrogen (100, 125 and 150 kg N ha -1 ). Split split plot design was used in layout of experiment. Nitrogen application markedly enhanced growth and yield but resulted in decrease in seed oil percentage. Nitrogen levels of 125 kg ha -1 produced significantly higher achene s yield (3.36 t ha -1 ) than those plots receiving 150 and 100 kg N ha -1. The hybrid S-278 stood out maximum for head diameter, number of achene s head -1, 1000- achene s weight, achene yield except plant height. Maximum achene s yield in addition to accumulation of highest oil contents was recorded in S-278 hybrid and that was 3.35t ha -1. Increasing plant density increased the plant height, achene yield and oil contents. By contrast, head diameter, 1000- achene s weight and seed yield per plant reduced with increasing planting density. Concerning the interaction between planting densities and nitrogen, the highest achene yield (3.96 t ha -1 ) was obtained with closer plants at 20 cm plant spacing and 125 kg N ha -1 application. Keywords hybrids, nitrogen, planting densities, sunflower, yield. I I. INTRODUCTION n the world trade sunflower (Helianthus annuus L) oil is the fourth vegetable oil with an annual production of around 9 million tons [1]. However, productivity of sunflower in Pakistan is very low and possible reason for it is the nonadoption of new developed short stature hybrids with higher fertilizer requirements. The farmers are applying inappropriate planting geometries and low nitrogen rates. Therefore, sowing of newly developed hybrids, with appropriate geometries and Amjed. Ali, is with the University College of Agriculture, Sargodha, Pakistan (corresponding author to provide phone: 00923336800878 ; e-mail: amjedalich@yahoo.com ). Ashfaq.Ahmad, and Tasneem Khaliq are with the University of Agriculture,FaisalabadPakistan(email:aachatha@yahoo.com). Tasneeem Khaliq@gmail.com).Muhammad Afzal and Zafar Iqba are with the University College of Agriculture, Sargodha, Pakistan. (e-mail: chafzal64@yahoo.com, zafarrohils@yahoo.com ). high nitrogen rates are considered as promising strategy in order to increase edible oil production for food security and reduce the import bills [2, 3]. Sunflower production is greatly affected by choice of hybrid. Bakht et al [4] worked on performance of various sunflower hybrids and found a significant difference in yield and yield components of various hybrids. He reported that one of the reasons for low sunflower seed production is the cultivation of exotic hybrids, which are not well adapted to agro-climatic conditions of Pakistan. We have to select such hybrids which can easily fit in our existing cropping pattern and in changed conditions. Karaaslan et al., [5] conducted the trial on determination of potential sunflower cultivars for the irrigated conditions of Diyarbakir and concluded that cultivar adaptation is important for regions in term of obtaining maximum yield. Nasim et al., [6] experimented on three sunflower hybrids and reported that hybrids have their own distinctive characteristics and yield potential. Plant spacing effects are highly pronounced in crops such as sunflower because there is no possibility of filling gaps between plants by branching and tillering. Thus an appropriate plant stand may help in harnessing all the renewable resources in a more and efficient manner toward high crop yields. Study on different planting patterns and nitrogen splits on rain fed sunflower showed that highest yield was observed at the closest spacing of 30 cm x 25 cm as compared to widest spacing of 30 x 35 cm [7]. Mojiri and Arzani, [8] demonstrated that increasing plant density had an incremental effect on plant height and negatively affects stem and head diameters. A plant density of 85000 plants ha -1 was observed as suitable plant density, whereas the higher plant density had a negative effect on seed yield. Beg et al., [9] noted that higher plant populations produce lighter seeds, thinner stems, taller plants and more yield than lesser plant density. Head diameter, 1000-seed weight, seed yield per head; seed yield per plant and seed straw and biological yield were increased by the N application while harvest index and seed oil percentage were decreased by the N application [10]. The objectives of this study therefore, were, to determine the effect of planting densities and different levels of nitrogen and on growth and yield and quality of sunflower hybrid for obtaining higher yield. 73
II. MATERIALS AND METHODS The Experiment was conducted at the Agronomy Research Area, University of Agriculture, Faisalabad during the spring seasons of 2010. The experiment was laid out in split split plot design having three replications, keeping net plot size 3.6 x 6 m. Sunflower hybrids (Hysun 33, S-278) were kept in main plots, planting densities (83,333, 66,666 and 55,555 plants ha - 1 by maintaining plant to plant distance 20, 25 and 30cm, respectively) randomized in sub plots and nitrogen rates (100, 125 (standard), 150 kg ha -1 ) in sub sub plots. The Crop was sown on 11 th March, 2010, with the help of a dibbler on 60 cm spaced ridges keeping plant to plant distance of 20, 25 and 30 cm. Phosphorus and potassium was applied at the rate of 60-30 kg ha -1, respectively. Nitrogen, phosphorus and potassium were given in the form of Urea, DAP and SOP (K 2 SO 4 ). 1/3 rd dose of nitrogen and all of P and K fertilizer was applied at the time of sowing and remaining 2/3 rd of N was applied in two splits, at first irrigation and flowering stage. All other cultural practices such as hoeing, irrigation and plant protection measures were kept normal for the crop. Half plot area of 2.40x6m from each plot was harvested for threshing and a sub sample of 10 plants was taken for the determination of different yield components. All plants was threshed for the estimation of plot yield and converted into t ha -1.The data was collected for plant height at maturity, Head diameter, Number of achene s per head, 1000-achene weight, Achene s yield, and Seed oil contents. The data collected on these parameters were statistically analyzed by employing the Fisher s analysis of variance technique and least significant difference (LSD) test at 0.05 level was used to compare treatment means [11]. III. RESULTS AND DISCUSSION A. Nitrogen Level Effect The data given in Table-1 revealed that nitrogen levels of 125 and 150 kg ha -1 produced statistically similar plant height, 182.72 cm and 183.44 cm, respectively but significantly higher than 100 kg N ha -1 treatment. Increase in plant height with nitrogen application has also been reported by Mukhtar et al., [12]. Maximum head diameter (19.92 cm) was recorded in case of those plots which were fertilized at the rate of 150 kg ha -1 while the minimum head diameter (16.18 cm) was recorded in case of plots which were fertilized with lowest rates of nitrogen (100 kg ha -1 ), while the treatment 125 kg ha -1 was intermediated. The significant effect of nitrogen application on head diameter has also been reported by earlier researchers [13]. Nitrogen application had significant effect on number of achene s per head. Highest number of achene s per head was recorded from plot which was fertilized with nitrogen rates of 150 kg ha -1, which was followed by nitrogen level of 125 kg ha -1, while the minimum number of achene s per head was noted from plot treated with 100 N kg ha -1. Similar results were reported by Salehi and Bahrani [13] Al- Thabet [14] and Ali et al., [15], who concluded that number of achene s per head was significantly increased as the nitrogen dose increases. Thousand achene weight was affected significantly by different levels of nitrogen fertilizer. The plots receiving nitrogen levels of 150 kg ha -1 produced statistically higher 1000- achene s weight than those plots receiving 125 kg N ha -1 and 100 kg N ha -1. These findings are supported by the observation of Ali et al., [16], who reported increase in thousand achenes weight with increasing fertilizer dose. Achene s yield kg ha -1 was affected significantly by all of the factors under study. Nitrogen levels of 125 kg ha -1 produced significantly higher achene s yield (3.36 t ha -1 ) than those plots receiving 150 and 100 kg N ha -1. Lowest achene s yield (2.77 t ha -1 ) was recorded in case of those plots which were fertilized at the rate of 100 kg ha -1. These results are in confirmatory with those of earlier scientists [14], who reported that yield increased with increasing rates of nitrogen. Results indicated that oil content decreased with an increase in the level of nitrogen. Nitrogen levels of 100 kg ha -1 produced significantly more oil contents (39.63 %) than 125 kg N ha -1 (38.95 %) and 150 kg N ha -1 (37.98 %). These results are supported by the findings of earlier researchers [10]. B. Hybrids Effect Data in Table 1 showed that sunflower hybrid had significant effect on plant height. Hysun-33 hybrid obtained highest plant height (194.19cm) as compared to Hybrid S- 278(164.63 cm). These results are also in accordance with earlier workers [16], who reported that sunflower cultivars significantly differed in plant height and this difference may be due to varietal behavior. The sunflower hybrid S-278 produced significantly higher head diameter (20.33cm) as compared to Hysun-33 (15.71cm). Nasim et al., [6] also observed significant difference for head diameter trait among sunflower hybrids. S-278 hybrid produced significantly higher number of grains per head (1362.25) than Hysun-33 (1092.04). These results agreed with those reported by Bakht et al., [4]. Thousand achene weight of hybrid S-278 (64.68g) was higher than Hysun-33, (57.54g). The maximum grain yield of (3.35 t ha -1 ) was recorded from hybrid S-278 as compared to hybrid Hysun-33 which produced (2.90 t ha -1 ) achene s yield. Bakht et al (4), Karaaslan et al., [5] and Nasim et al., [6] also found significant difference among hybrids for achene yield potential among various hybrids. Hybrid S-278 produced significantly higher oil contents (39.78 %) as compared to hybrid Hysun-33 (37.92 %). The effect of plant spacing on achene oil contents was also found to be significant. C. Planting Densities Effect As regard plant spacing, significantly maximum plant height (191.5cm) was observed in case of 20cm plant spacing which was followed by 25cm plant spacing (178.44 cm) while minimum (168.28cm) plant height was recorded at 30cm spaced planting. These results are in line with the findings of Mojiri and Arzani, [8], Beg et al., [7] who reported that plant height increased with increasing plant population in the field. Effect of plant spacing was highly significant and 30cm plant spacing resulted in significantly larger head diameter (20.13 74
cm) followed by 25 cm plant spacing (18.02cm), while 20 cm plant spacing resulted in significantly smaller head diameter (15.89cm). There was a linear increase in head diameter with increase in plant spacing. These results are supported with the findings of Mojiri and Arzani, [8], Salehi and Bahrani (14) and Al-Thabet (14) who concluded that head diameter was significantly increased with increase in plant spacing. Plant spacing of 25cm produced significantly higher number 1326.06 which was statistically at par with the number of achene s head -1 at planting density of 30 cm plant spacing but minimum 1039.22 of achene s per head recorded from 20 cm spaced planting. The decreased in number of achene s per head with increasing plant population might be due to more competition among plants in case of nutrients light, moisture due to less pacing. These results are supported by Mojiri, and Arzani [8] they concluded that number of achene s per head was increased with decreasing plant density. Effect of plant spacing was highly significant and 30cm plant spacing resulted in significantly more 1000 achene s weight (63.87g) followed by 25cm plant spacing (60.27g) and 20 cm plant spacing (59.19g) which were statistically similar with each other. The findings are in conformity with the findings of Al- Thabet [14], who demonstrated that 1000 achene weight decreased with increasing plant density. The effect of plant spacing on achene s yield was also found to be significant. The highest seed yield was produced (3.66 t ha -1 ) when sunflower plants were planted at 20 cm followed by 25cm plant spacing (3.16 t ha -1 ). Significantly fewer yields (2.60 t ha -1 ) were obtained at plant spacing of 30 cm. The increase in achene s yield plant with increasing plant spacing might attributed to increase in head diameter and 1000 achene s weight. The positive effect of closer plant spacing as obtained in the present study agreed well to the findings of Vijaykumar et al., [7], who observed highest achene yield in closest plant spacing. Sunflower hybrids have significant effect on seed oil contents percentage. The highest seed oil contents (39.98 %)was found when sunflower plants were planted at 20 cm which was statistically similar with 25cm plant spacing oil contents percentage(39.13 %). Significantly less oil contents of 37.45 % was obtained at plant spacing of 30 cm. D. Interactive Effects of Planting Densities and Nitrogen The interaction among planting densities and nitrogen significantly affected all studied parameters. In this context, the highest values of plant height were obtained from plants grown at 20 cm plant spacing and fertilized with 150 kg N ha -1 while minimum plant height was obtained from plants grown at 30 cm plant spacing and fertilized with 100 kg N ha -1. Maximum head diameter (22.47cm) was observed in D 3 N 3 (30 cm plant spacing, 150 kg N ha -1 ) which was followed by D 3 N 2 (30 cm plant spacing, 125 kg N ha -1 ) and D 2 N 3 (25 cm plant spacing, 150 kg N ha -1 ) obtaining (20.05, 19.71 cm), respectively. Similarly in D 3 N 3 (30 cm plant spacing, 150 kg N ha -1 ) maximum number of achenes head -1 (1476) was noted which were statistically at par with D 2 N 3 in which number of achenes head -1 was (1460) while minimum (903) was in treatment D 1 N 1 (20 cm plant spacing, 100 kg N ha -1 ). While, 1000- achene weight was statistically similar for D 2 N 3, D 1 N 3, D 3 N 3, D 3 N 2 treatments and was significantly different from all the other treatments such as D 2 N 2, D 3 N 1, D 1 N 2, D 2 N 1, D 1 N 1. Whereas, highest achene yield (3.96 t ha - ) was produced in D 1 N 2 treatment which was statistically similar with D 1 N 3 treatment and lowest (2.43 t ha - ) was noted in D 3 N 1. However, the highest and lowest value for achene oil contents (40.42, 38.02 %) was noted in D 1 N 1 and D 3 N 3 treatments, respectively. IV. CONCLUSIONS Nitrogen and planting densities has a significant effect on sunflower growth, yields and quality parameters. However, excess nitrogen reduced the seed yield as well as oil contents. In case of planting density it can be concluded that the increase in density affects most of traits of sunflower and consequently, increase achene yield per unit area which is more the result of the increase in plant number per unit area as compared to yield per plant. Sunflower hybrid S-278, sowing on 20 cm plant spacing and the application of 125 kg N ha -1 is the recommended treatment for obtaining maximum return under the environmental conditions of this study. REFERENCES [1] Vollmann, J. and I. Rajcan. 2009. Handbook of plant breeding. Springer Dordrecht Heidelberg London New York. [2] Malik, M.A., S.H. Shah, S. Mahmood and M. A. Cheema.2001. Effect of various planting geometries on the growth, seed yield and oil content of new sunflower hybrid (SF-187). Int. J. Agri. Biol., 3 (1): 55-56. [3] Zahoor, A., M. Riaz, S. Ahmad, H. Ali, M. B. Khan, K. Javed, M. A. Anjum, M. Zia-Ul- Haq, M. A. Khan. 2010. Ontogeny, growth and radition use efficiency of Helianthus annuus L. as affected by hybrids, nitrogenous regimes and planting geometry under irrigated arid conditions. Pak. J. Bot. 42(5): 42: 3197-3207. [4] Bakht J., S. Ahmad, M. Tariq, H. Akbar and M. Shafi. 2006. Performance of various hybrids of sunflower in Peshawar valley. J.Agri.Sci., 3: 25-29. [5] Karaaslan D., A. Hatipoglu, Z. Turk and Y. Kaya. 2010. Determination of potential sunflower cultivars for the irrigated conditions of Diyarbakir. Helia, 33(52): 145-152. [6] Nasim, W., A. Ahmad, A. Bano, R, Olatinwo, M. Usman, T. Khaliq. A. Wajid, H. M. Hammad, M. Mubeen, M. Hussain.2012. Effect of nitrogen on yield and quality of sunflower (Helianthus annuus L.) hybrids under sub humid conditions of Pakistan. American J. of plant Sci., 3: 243-251. [7] Vijaykumar, M., P. Subbin and R. Selvaraju. 2003. Effect of plant population and split application of nitrogen on growth and grain yield of sunflower under rainfed condition. Mysore. J. Agri. Sci., 35:305-312. [8] Mojiri, A. and A. Arzani. 2003. Effects of nitrogen rate and plant density on yield and yield components of sunflower. J. Sci. Technol. Agric. And Natural Resources, 7: 115-125. [9] Beg, A., S. S. Pourdad and S. Alipour. 2007. Row and plant spacing effects on agronomic performance of sunflower in warm and semi-cold area of Iran. Hella, 30(47): 99-104.. [10] Kasem, M. M. and M.A. El-Mesilhy. 1992. Effect of rates and application treatments of nitrogen fertilizer on sunflower yield and yield components. Annals Agric. Sci. Moshtohor. 30(2): 665-676. [11] Steel, R.G.D., J.H. Torrie and D. A Dickey. 1997. Principles and procedures of statistics: A biometerical approach. 3rd ed. Megraw Hill book Co. Inc. New York: 400-428. [12] Mukhtar, T., M. Arif, S. Hussain, M. Tariq and K. Mehmood. 2011. Effect of different rates of nitrogen and phosphorus fertilizers on growth and yield of maize. J. Agric. Res., 49(3): 333-339. [13] Salehi, F. and M. J. Bahrani. 2003. Sunflower summer- planting yield as affected by plant population and nitrogen application rates. Iran Agric. Res. 19 (1): 63-72. 75
[14] Al-Thabet, S.S. 2006. Effect of plant spacing and nitrogen levels on growth and yield of sunflower (Helianthus Annus L.). King Saud Univ. Riyadh. J. Agric. Sci., 19: 1-11. [15] Ali, H., M. Riaz, A. Zahoor and S. Ahmad. 2011. Response of sunflower hybrids to management practices under irrigated arid-environment. African journal of biotechnology. Vol. 10(14), pp 2666-2675. [16] Ali, H., S.A. Randhawa and M. Yousaf. 2006. Quantitative and qualitative traits of sunflower as influenced by planting dates and nitrogen application. International journal of agriculture and biology.1560-8530/2004/06-2-410-412. TABLE I EFFECT OF NITROGEN ON PLANT HEIGHT, HEAD DIAMETER, NUMBER OF ACHENE HEAD -1, 1000-ACHENE WEIGHT, ACHENE YIELD AND OIL CONTENTS OF SUNFLOWER HYBRIDS UNDER VARYING PLANTING DENSITIES Treatments Hybrids Plant height (cm) Head diameter (cm) Number of achenes head-1 1000 achene weight Achene yield (t ha- 1) Achene oil contents (%) H 1 (Hysun-33) 194.19a 15.71 b 1092 b 57.54 a 2.90 b 37.92 b H 2 (S-278) 164.63b 20.32 a 1362 a 64.68 a 3.35 a 39.78 a LSD value 4.708 0.746 51.78 7.166 0.428 1.502 Plantingdensities D 1 (20cm) 191.5 a 15.89 c 1039 b 59.19 b 3.66 a 39.98 a D 2 (20cm) 178.44 b 18.02 b 1326 a 60.27 b 3.16 b 39.13 a D 3 (20cm) 168.28 c 20.14 a 1316 a 63.87 a 2.60 c 37.45 b LSD value 4.001 0.502 46.218 1.703 0.189 0.862 Nitrogen rates N 1 (100 kg ha -1 ) 172.06 b 16.18 c 1083 c 54.92 c 2.77 c 39.63 a N 2 (125 kg ha -1 ) 182.72 a 17.95 b 1223 b 61.94 b 3.36 a 38.95 b V. REFERENCES N 3 (150 kg ha -1 ) 183.44 a 19.92 a 1373 a 66.46 a 3.28 b 37.98 c LSD value 2.597 0.224 13.572 0.725 0.068 0.271 Interactions HxD NS NS NS NS NS NS HxN NS NS NS NS NS NS DxN * * * * * * LSD value 5.423 0.593 50.003 1.986 0.212 0.618 Means followed by similar letters in each column are not significantly differ at the 5 % level of probability. NS = non significant. * Significant. 76
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