RESPONSE OF SUNFLOWER HYBRIDS TO DIFFERENT NITROGEN LEVELS FOR PHYSIOLOGICAL AND AGRONOMICAL TRAITS UNDER FIELD CONDITIONS

Transcription

1 Pkistn J. Agric. Res. Vol. 9 No1, 016 RESPONSE OF SUNFLOWER HYBRIDS TO DIFFERENT NITROGEN LEVELS FOR PHYSIOLOGICAL AND AGRONOMICAL TRAITS UNDER FIELD CONDITIONS Doult Big*, Fid Mohmmd Asi*, Hi Ahmed*, Mqsood Qmr** nd Muhmmd Ayu Khn** ABSTRACT:- Sunflower occupies min position mong oil seed crops in Pkistn. Mostly indigenous sunflower hyrids re cultivted which give low chene nd fodder yields. The issue relted with these hyrids scried to lck of informtion out use of inputs nd culturl prctices. Judicious nitrogen use nd suitle high yielding hyrid ply key role in incresing sunflower productivity. Protein is the sic requirement of the metolic processes for the vegettive, reproductive growth nd yield of the crop. The protein is wholly dependent upon the mount of nitrogen fertiliztion ville in soil for the plnt use. A two yer study ws conducted in 01 nd 013 t Ntionl Agriculturl Reserch Centre (NARC), Islmd, Pkistn. The experiment ws imed to 1 1 evlute the effect of different nitrogen (N) levels (N = 0 kgh, N = 60 kgh, N = kgh, N = 10 kgh, N = 180 kgh nd N = 40 kgh ) on two sunflower hyrids, SMH-0907 nd SMH-0917 to optimize the N levels for otining mximum yield on sustinle sis. Both hyrids were kept in the min plot while N levels in the su plot in rndomized complete lock design with three replictions. The results showed tht the numer of chene hed, 100-chene weight nd chene yield incresed with incresed N ppliction. The incresed levels of N lso enhnced the chene yield. The mximum chene yield ( kg h ) ws recorded t 180 kg N h followed y 40 kg N h. Minimum chene yield (115 kg h ) ws oserved in control tretment (N 0). Polynomil regression line showed tht the rte of yield increse ws higher up to 180 kg N h nd ecome slow therefter. The hyrid SMH-0907 produced more chene (736 kg h ) s compred to the hyrid SMH-0917 (694 kg h ). Results reveled tht economized ppliction of different doses of N cn oost up the yield in oth sunflower hyrids SMH-0907 nd SMH These findings could e helpful in rtionlizing most vlule inputs such s nitrogen in sunflower crop. It cn e deduced tht the 1 ppliction of 180 kg N h cn provide the est comintion for good yield in sunflower crop under the previling humid conditions of Pkistn. Key Words: Sunflower; Hyrid; Achene Yield; Crop Growth Rte; Hrvest Index; Lef Are Index; Net Assimiltion Rte; Irrigtion Levels; Plnting Methods; Pkistn. INTRODUCTION Sunflower (Helinthus nnuus L.) is n nnul crop hving ulky flower cpitulum. It is grown for oil, edile seed s well s for forge purposes. Sunflower * Hzr University, Mnsehr, Pkistn. ** Ntionl Agriculturl Reserch Centre, Islmd, Pkistn. Corresponding uthor: ig011@yhoo.com 14 ws initilly domesticted in North Americ nd then it spred to other prts of the world. It is short durtion crop (95 dys) mturity hence cn e fitted in the current cropping pttern hving short window for ny incorpo-

2 DOULAT BAIG ET AL. rtion of short durtion crop without considerle ltertion. On the other hnd hving genotypic ility it cn withstnd wide rnge of temperture o (17.8º-3.8 C) (Mirshekri et l., 01). Sunflower seed contins 40-50% oil nd 17-0% protein (Bkhsh et l., 1999). In Pkistn sunflower ws domesticted s oil seed crop in erly sixties. At tht time the totl re under the crop ws 670 h with 480 t of totl production. The re strted to increse in ut with considerle fluctution on yer to yer ses (GoP, 1995). Sunflower is successfully grown in Pkistn under different soil/climtic conditions nd cropping systems. It is mostly in rice (70%) nd cotton (0%) growing res. It is very interesting tht sunflower production is lmost doule ( kg h ) in cottonsunflower re ginst kg h in ricesunflower growing res tht rings country's ntionl verge to 150 kg h. Sindh is the province of Pkistn where mximum re, 60-88% of the totl sunflower is grown in rice frming system. Currently domestic edile oil production is 567 mt s compred to 50 mt of oil which is Rs. 4 illion. (GoP, 014). A numer of iotic nd iotic fctors re responsile for potentil yield of sunflower crop. A fertile soil provides ll essentil nutrients for plnt. As n importnt constituent of protein, N plys significnt role in vegettive nd reproductive growth cusing increse in sunflower yield (Steer nd Hocking, 1984). N hve different role in plnt such s it enhnces photo-synthesis rte (Fyyzul-Hssn et l., 005). The incresed N ccumultion nd dispersion into different plnt prts will enhnce the growth nd development nd ultimtely increse the yield of crop (Khliq nd Cheem, 005). They concluded tht t certin level of fertility, dditionl doses did not further enhnce the yield. The present study is imed to investigte the physiology nd gronomic response of two sunflower hyrids to different nitrogen levels under field conditions. MATERIALS AND METHOD A rndomized complete lock design (RCBD) ws dopted with split plot rrngement. Sunflower hyrids were kept in min plots nd N levels were kept in su-plots (Tle 1). The tretments were repeted thrice. The experiment consisted of five N levels (0, 60, 10, 180 nd 40 kg N h ) nd two sunflower hyrids nmely, SMH nd SMH Experimentl field ws lso irrigted efore seeded preprtion nd field ws ploughed - 3 times, ech followed y plnking. The source of NPK ws ure, single super phosphte nd murite of potsh, respectively. Full dose of P nd K (60 kg PO 5 nd 10 kg K O h ) ws pplied t plnting time while N ws divided into Tle 1. Tretments (kg h ) (kg h Hyrid N P O 5 K O ) (kg h ) SMH T 1 Arrngement of N levels T SMH T 3 SMH T 4 SMH T 5 SMH T 6 SMH T 7 SMH T 8 SMH T 9 SMH T 10 SMH

3 RESPONSE OF SUNFLOWER HYBRIDS TO DIFFERENT NITROGEN LEVELS two hlves. One hlf ws pplied t plnting time; remining N ws pplied t first irrigtion. The crop ws plnted on Ferury 9, 01 nd Mrch 14, 013 through diler y dropping two seeds per hill. Totl numer of four irrigtions ws pplied t seedling, uttoning, flowering nd seed setting stges in oth the experimentl yers. Stndrd gronomicl prctices nd plnt protection mesures were followed. The meteorologicl dt (temperture, pn evportion rte, rinfll nd reltive humidity) were recorded during the experiment (Tle ). All meteorologicl dt were otined from the mesurement mde t the Meteorologicl Oservtory t NARC.The soil smples were collected from the 05 cm profiles nd nlyzed. The soils re lkline, non-sline nd slightly to modertely clcreous (Tle 3). The soil ws lomy in texture. Dt ws recorded on physiologicl (lef re index t 40 nd 65 dys Tle. Months 01 Jnury Ferury Mrch April My June July 013 Jnury Ferury Mrch April My June July Temperture o (C ) Mx Min Pn Evp. (mm) Rinfll (mm) Avg. reltive humidity (%) Meteorologicl dt recorded during the experiment t 0800 h nd 1400 h dily) Tle 3. Soil property ph Ece (dsm ) K (mg kg ) N (mg kg ) NO3-N (mg kg ) P (mg kg ) OM (%) HCO 3 (mg kg ) CI (mg kg ) C+Mg (mg kg ) Cly (%).61.4 Silt (%) Snd (%) Texture clss Lom fter sowing nd hrvest index) nd gronomic (numer of chene hed, 100-chene weight nd chene yield) prmeters. Physiologicl Prmeters Lef Are Index (LAI) nd Net Assimiltion Rte (NAR) Lef re index (LAI) ws mesured with help of n electronic device MK (Are mesurement system, Delt T-Devices Ltd, Burwell Cmridge Englnd). The - dry weight ws expressed in g m dy ) nd ws clculted using the following formul: LAI = Soil chrcteristics of experimentl field in 01 nd 013 Lef re per plnt (dm ) Ground re covered y the plnt (dm ) Hrvest Index (HI) Hrvest index (HI) s the rtio of the seed yield to totl iologicl yield (ove ground iomss) ws clcu-lted y following formul: HI % = Seed yield/biologicl yield 16

4 Agronomic Dt Numer of Achene Hed, 100- Achene Weight (g) nd Achene Yield (kg h ) Ten hed rndomly selected to count for numer of chene hed. The heds were rndomly selected from centrl rows of ech su plot t mturity. For 100 chene weight, 100 chenes were rndomly selected from seed lot nd their weight ws expressed in grms. At mturity ll heds were threshed mnully from ech su-plot. Fresh seed yield of ech plot ws recor- ded nd converted into kg h. Smples of seeds from ech plot were tken rndomly to ssess moisture contents nd dry weight ws mesured. The chene yield (AY) ws determined s follows: Dry weight of smple AY= x totl weight x Fresh weight of smple Tle 4. DOULAT BAIG ET AL. Sttisticl Anlysis For sttisticl nlysis Sttistix 8.1 ws dopted. Anlysis of vrince ws used to mesure vrition mong the tretments (Steel nd Torrie, 1981) while the lest significnt difference ws used to compre tretments. Differences mong the men vlues were seprted y LSD for elucidtion of the results. The polynomil regression nlysis ws done nd optimum dose of nutrient elements for mximum chene yield nd economic rte of inputs were clculted from simple polynomil regression equtions: Y = α + β 1x + βx (Zmn et l.,198) where, x = Independent vrile (N ) Y = Dependent vrile (yield nd. other prmeters) RESULTS AND DISCUSSION Response of Physiologicl Chrcter to N Levels Lef Are Index (LAI) Anlysis of vrince showed tht ll types of interctive effects were non-significnt, however min effect of yer hyrid nd nitrogen level were highly significnt (P< 0.01) on lef re index t 40 dys fter sowing (Tle 4). LAI of sunflower hyrid t 40 dys fter sowing ws significntly incresed with the increse of nitrogen Anlysis of vrince for effect of N levels on different prmeters of sunflower during 01 nd 013 source DF LAI 40 LAI 65 HI (%) 100 ACW NO-ACH ACY (kg) N levels ** ** ** ** 13011** 17143** Hyrids ** 5.340** ** ** 8733** 5503ns Yer **.04** 5.70** ** 95ns 31049** N levels x hyrids ns 0.049ns ** 0.475ns 3845** 6043* N levels x Yers ns 0.06** ** ns 4470** 4554ns Yrids x yers ns 0.00ns ns ns 791** 10540* N levels x hyrids ns ns 0.104ns 0.15ns 1849** 400ns x yers Error LAI 40 = Lef re index t 40 dys fter sowing, LAI 65 = Lef re index t 65 dys fter sowing, HI = Hrvest index, 100 ACW = 100-chene weight, NO-ACH = numer of chenes per hed nd ACY = Achene yield * nd ** = Significnt t 0.1 nd 0.05 percent, respectively 17

5 RESPONSE OF SUNFLOWER HYBRIDS TO DIFFERENT NITROGEN LEVELS fertilizer. It ws highest (0.81) with 180 kg N h followed y 40 kg N h (Figure 1). It ws lowest (0.33) t 40 dys fter sowing in control where no nitrogen ws pplied. Thus the response of LAI t 40 dys fter sowing ws lmost liner up to 180 kg N h ut reverse trend ws oserved eyond tht point. The polynomil regression nlysis (Figure1) showed strong positive correltion (R =0.849) etween nitrogen levels nd LAI fter 40 dys of sowing. The effect of yer t 40 dys fter sowing ws highly significnt (P< 0.01). Results showed 6% higher LAI t 40 dys fter sowing in 013 thn 01 (Tle 5). The hyrid SMH-0917 showed higher LAI t 40 dys fter sowing thn the hyrid SMH-0907 (Tle 6). Interctive effect of N level x yer ws significnt while ll other such effects were non-significnt (Tle 4). The min effect of yer, hyrid nd nitrogen level were highly significnt (P< 0.01) on LAI t 65 dys fter sowing. The LAI ws significntly incresed with the increse of nitrogen fertilizer up to 180 kg h nd there ws decrese therefter (Figure 1). Results showed tht the highest LAI (4.5) ws recorded t 65 dys. With the ppliction of 180 kg N h s compred to 1.68 in control (Figure 1). This shows 168% increse over control. The polynomil regression nlysis lso showed strong positive correltion (R = 0.943) etween nitrogen levels nd LAI t 60 dys fter sowing. The higher LAI t optimum N level could e scried to the higher rte of cell division followed y enlrgement Tle 5. Men effect of yers (01 nd 013) on different prmeters of sunflower Yers LAI 40 Dys LAI 65 Dys 3.07 HI (%) 100 ACW (g) NO ACH ACY (kg h ) Mens followed y sme letter do not differ significntly s reported erlier reserchers (Bnge et l., 000; Cechin nd Fumis, 004). The overll finding showed tht plnt responded to nitrogen ppliction nd this response is proportionl up to 180 kg N h nd decreses further s nitrogen level increses (Figure 1). Oliveir et l. (01) reported tht optimum nitrogen supply increses crohydrte synthesis nd utiliztion, hence promoting plnt growth. Wheres with indequte nitrogen the reverse phenomen of low crohydrte synthesis nd utiliztion results in slower growth of Tle 6. Men performnce of sunflower hyrids for different prmeters during 01 nd 013 Hyrids SMH-0907 SMH-0917 LAI 40 Dys LAI 65 Dys HI (%) 100 ACW (g) NO ACH 1.68 d 0.33 e ACY (kg h ) Y= -0.5x² +.11x R² = c 0.45 d Y= -0.04x² x R² = c Mens followed y sme letter do not differ significntly. 3.8 LAI t 40 dys LAI t 65 dys Poly. (LAI t 40 dys) Poly. (LAI t 65 dys) Figure 1. Effect of N level on lef re index 18

6 DOULAT BAIG ET AL. vegettive cells. The response of sunflower hyrids ws lso significnt, s SMH-0907 showed 1% higher LAI t 65 dys fter sowing thn SMH Yer wise effect showed tht LAI t 65 dys ws greter (1%) during 013 s compred to 01. This could e scried to the fvorle wether conditions. Similr effect ws lso reported y Dr et l. (009) who climed tht yer (environment) hd significnt effect on LAI. These results re in conformity with Nsim et l. (011) who oserved tht the growing conditions s well s seson hd significnt effect on mximum LAI t 65 dys fter sowing throughout the growth. Hrvest Index(HI) The interctive effect of N level x hyrid nd N level x yer ws highly significnt on hrvest index (HI) wheres remining types of interction were non-significnt. The min effect of nitrogen, yer nd hyrid were lso highly significnt (Tle 4). All the five nitrogen tretments gve significntly different HI from ech other. Polynomil regression line lso confirmed tht the rte of HI increse ws higher up to 180 kg N h nd ecome slower therefter. Regression nlysis lso demonstrted strong correltion (R = 0.984) etween nitrogen ppliction nd HI (Figure 1). The result showed tht s nitrogen ppliction is incresed the HI goes on incresing which endorsed tht more photossimiltes hve een chnnelized into chene yield with increse in nitrogen ppliction. This results in high HI. The increse in HI from 1% to 5% ws oserved with ppliction of 600 kg N h. These results mtched with those of Ysin et l. (013) who reported significnt response of HI to Figure 1. Effect of N level on hrvest index (%) vrious N levels. The HI ws 6% greter in 013 thn 01 (Tle 6). Similrly, the hyrid SMH-0907 gve 5 % more HI thn the hyrid SMH-0917 (Tle 5). These results hve show the reltive dominnce of SMH-0907 over SMH-0917 to utilize photo-ssimiltes into chene yield. Sinclir (1998) hs lso reported the pproch of reltive dominnce in sunflower hyrid with respect to hrvest index. The effect of two wy interction of hyrid x N level on HI ws highly significnt. In hyrid N interctions, mximum HI (4.86) ws given y hyrid SMH-0907 with N level of 180 kg h while minimum HI (18.99) ws ttined y SMH-0917 from control plot without nitrogen ppliction (Tle 7). Response of Agronomic Chrcters to N Levels 100 Achene Weight (g), Numer of Achene Hed nd Achene Yield (kg h ) HI Poly. (HI) 19.46d 1.7 c 3.4 Y = -0.59x x R = Interctive effects of yer x hyrid, N level x hyrid, N level x yer nd yer x hyrid x N were non-significnt on 19

7 Tle 7. N levels Hyrids LAI 40 dys LAI 65 dys 100- chene weight (Tle 4). However, min effect of N level, hyrid nd yer ws highly significnt (P< 0.01) on 100- chene weight. All the nitrogen levels expressed significntly different effects on 100-chene weight from ech other (Figure ). The polynomil regress-ion nlysis showed tht there ws strong positive correltion (R = 0.863) etween nitrogen levels nd 100- chene weight. The rte of 100-chene weight incresed up to 180 kg N h HI (%) 100 AW ACH ACY (kg) 0 SMH SMH SMH SMH SMH SMH SMH SMH SMH SMH d Response of interction hyrid x N levels on different prmeters of sunflower 100 ACW (g) RESPONSE OF SUNFLOWER HYBRIDS TO DIFFERENT NITROGEN LEVELS Poly. (100 ACW(g)) 4.9 c 6 Y = x² +.764x R² = Figure. Effect of N level on 100- chene weight (g) 0 nd ecome slower susequently. The highest 100-chene weighs (7. g) ws otined from the ppliction of 180 kg N h followed y the ppliction of 10 kg N h (6 g). This increse in 100-chene weight ws 89% nd 57%, respectively over control (3.85g). The hyrid SMH-0907 produced 1% (6.07g) higher 100-chene weight thn SMH- 0917(5.03 g) (Tle 5). Therefore, hyrid SMH-0907 ws comprtively more effective over SMH-0917 for 100-chene weight. Significntly greter 100-chene weight ws hrvested in 013 thn 01 (Tle 6). The increse in 100-chene weight ws 1% (6.07 g vs g) in 013 s compred to the 01. These findings re lso in line with those of Ghni et l. (000), Zuillge et l. (00), Killi (004) nd Adel-Motglly nd Osmn (010) who oserved greter 100-chene weight with incresed level of nitrogen ppliction. All interctive effects s well s min effects highly significntly ffected the numer of chene per hed except the effect of yer (Tle 4). The two wy interction of yer x hyrid showed tht

8 the mximum chene per hed (799) were noted on hyrid SMH-0907 in 013 wheres the minimum numers of chene per hed (73) were produced y hyrid SMH-0917 in the sme yer (Tle 8). In hyrid x N fertilizer level interction, the highest numer of chene per hed (944) ws otined y hyrid SMH-0907 with 180 kg N h while the lest numer of chene per hed (639) ws ttined y hyrid SMH-0917 from control plot (Tle 7). In three wy interctions, yer x hyrid x N level, the highest numer of chene per hed (946) ws produced y hyrid SMH-0907 with 180 kg N h during the 013 wheres the lowest numer of chene per hed (605) ws produced y hyrid SMH-0917 during 01 in control plot. Results showed tht numer of chene per hed increses s nitrogen ppliction rte is incresed, showing mximum numer of chene per hed (897) with ppliction of 180 kg N h wheres the minimum numer of chene per hed (64) were hrvested from the plots with no nitrogen ppliction (Figure ). There is s much s 40% increse in numer of chene per hed over control where no nitrogen ws pplied. On the whole, nitrogen ppliction showed n increse of 7-40% y ppliction of kg N h over the control. However, eyond 180 kg N h, there ws negtive effect of N level on numer of chene per hed (Figure ). The polynomil line lso reveled tht the rte of nitrogen fertilizer increses the numer of chene per hed up to 180 kg N h nd showed negtive effect fterwrd (Figure Tle 8. DOULAT BAIG ET AL d e c Y = 3.4x x R = NO ACH Poly. (NO ACH-) ). The regression coefficient lso showed highly positive correltion (R = 0.877) etween the nitrogen rtes nd numer of chene per hed. The increse in numer of chene per hed my e ttriuted to more vegettive growth nd viility of chene (seed setting) due to nitrogenous fertilizer. These results re lso in line with those of Killi (004) nd Oliveri et l. (01) who lso climed tht the higher nitrogen rtes significntly increses the numer of chene per hed. The nitrogen ffects numer of chene per hed y influencing numer of growth prmeters such s LAI, plnt height, growth rte etc nd thus more vigorous growth nd development (Bindr nd Khrwr, 199 nd Srmh et l., 199). Numer of chene per hed hs n importnt role s prt of finl chene yield. Ysin et l. (013) reported tht numer of chene per hed is n importnt yield component which contriutes mterilly towrds finl chene yield of sunflower. The effect of interction such s Response of interction Hyrid x Yers on different prmeters of Hyrids Yers LAI 40 dys LAI 65 dys HI (%) 100 AW NO-ACH ACY (kg) SMH SMH SMH SMH (NACH) Figure. Effect of N level on numer of chene/hed

9 RESPONSE OF SUNFLOWER HYBRIDS TO DIFFERENT NITROGEN LEVELS yer x N level nd N level x hyrids x yer did not significntly ffect chene yield of sunflower hyrids (Tle 4). However the effect of interction of yer x hyrid nd hyrid x N level significntly ffected the chene yield. This shows tht the sunflower hyrids response differently to vrious levels of N under different environmentl conditions for yield. For exmple the highest chene yield (343.8 kg h ) ws produced y the hyrid SMH-0907 with 180 kg N h while the lowest chene yield (085 kg h ) ws produced y the hyrid SMH t control (Tle 7). Similrly, the highest chene yield (850 kg h ) ws produced y the hyrid SMH-0907 during 013 wheres the lowest yield ws lso hrvested from the sme hyrid during 01 (Tle 8). Adel- Motglly nd Osmn (010) lso reported the differentil response of sunflower genotypes to different N levels nd environmentl conditions. Results showed tht the effects of nitrogen nd yer were highly significnt nd effect of hyrid ws nonsignificnt (Tle 4). There ws significnt difference etween nitrogen levels for chene yield (Figure 3). The mximum chene yield of 3170 kg h d c ws chieved t the ppliction of 180 kg N h which is lmost doule yield over control (114.7 kg). The polynomil regression nlysis (Figure 3) reveled tht there is strong positive correltion (R = 0.975) etween N ppliction nd chene yield. The clculted optimum level of N for mximum yield is 180 kg h. However, incresing of N level eyond 180 kg h cuses reduction in the chene yield. The dt revels tht the optimum level of N improves sunflower plnt growth with vigorous growth rte, high lef re index, more numer of chene per hed nd 100-chene weight which results in increse of the chene yield. Mny erlier workers such s Ghni et l. (000), Zuillge et l. (00) Killi (004) nd Aedel-Motglly nd Osmn (010) lso reported greter response in chene yield with nitrogen ppliction. They viewed tht the fvorle level of N levels incresed the size nd numer of leves which increse LAI. Thus higher photosynthetic rte nd more fvorle condition led to good seed setting nd higher 100-chene weight which in turn incresed chene yield. It cn e thus deduced tht the y = -84.5x x R = ACY (kg) Poly. (ACY (kg)) Figure 3. Effect of N level on chene yield kg h )

10 DOULAT BAIG ET AL. sunflower hyrids response differently towrds different N levels nd environmentl conditions. However, optimum N level increses chene yield nd eyond tht level there is negtive effect on chene yield of sunflower. Under groecologicl condition of Islmd the ppliction of 180 kg N h is the optimum level for chieving the mximum chene yield. LITERATURE CITED Adel-Motglly, F.M.F. nd E.A. Osmn Effect of nitrogen nd potssium fertiliztion comintions on productivity of two sunflower cultivrs under est of El-ewinte conditions. Am. J. Agric. Environ. Sci. 8(4): Bkhsh, I., I.U. Awn nd M.S. Bloch Effect of vrious irrigtion frequencies on the yield nd yield components of sunflower. Pkistn J. Bio. Sci. (1): Bnge, M.P., G.L. Hmmer, S.P. Milroy nd K.G. Rickert Improving estimtes of individul lef re of sunflower. Agron. J. 9: Bindr, A. nd P.C. Khrwr Response of spring sunflower to nitrogen ppliction nd spcing. Indin J. Agron. 37: Cechin, I. nd T.F. Fumis Effect of nitrogen supply on growth nd photosynthesis of sunflower plnts grown in the greenhouse. Plnt Science, 166: Dr, J.S., M.A. Cheem, M.A. Whid, M.F. Sleem, M. Frooq nd S.M.A. Bsr Role of plnting pttern nd irrigtion mngement on growth nd yield of spring plnted sunflower (Helithus nnuus). Intl. J. Agric. Biol. 11: Fyyz-ul-Hssn, G., Qdir nd M.A. Cheem Growth nd development of sunflower in response to sesonl vritions. Pkistn J. Bot. 37: Ghni, A., M. Hussin nd M.S. Qureshi Effect of different irrigtion regimens on the growth nd yield of sunflower. J. Agric. Biol. (4): GoP Oilseed Development Strtegy, Ministry of Food Agriculture nd Livestock, Government of Pkistn, Islmd. GoP Ministry of Food Security nd Livestock, Economics Wing, Government of Pkistn, Islmd. Khliq, A. nd Z.A. Cheem Influence of irrigtion nd nitrogen mngement on some gronomic trits nd yield of hyrid sunflower. Intl. J. Agric. Bio. 7: Killi, F Influence of different nitrogen levels on productivity of oilseed nd confection sunflower (Helinthus nnuus L.) under vrying plnt popultions. Intl. J. Agric. Biol. 6(4): Mirshekri, M., N.M. Hosseini, R. Amiri nd O.R. Zndvkili. 01. Study the effects of plnting dte nd low irrigtion stress on quntittive trits of spring sunflower (Helinthus nnuus L.). Romnin Agric. Res.9: Nsim, W., A. Ahmd, A. Wjid, J. Akhtr nd D. Muhmmd Nitrogen effect on growth nd development of sunflower hyrid under groclimtic conditions of Multn. Pkistn J. Bot. 43(4): Oliveri, J.T.D., L.H.G. Chves, J.A.S. Junior, D.H.G. Filho nd V.B. Cmpos. 01. Response of sunflower to nitrogen ppliction nd wter in Northern Brzil Alfisol. Irnic J. Energy & Environ. 3(3): Srmh, P.C., S.K. Ktyl nd O.P.S. verm Growth nd yield of sunflower vrieties in reltion to 3

11 RESPONSE OF SUNFLOWER HYBRIDS TO DIFFERENT NITROGEN LEVELS fertility level nd plnt popultion. Indin J. Argon. 37: Sinclir, T.R Historicl chnges in hrvest index nd crop nitrogen ccumultion. Crop Sci. 38: Steel, R.G.D. nd J.H. Torrie Principles nd procedures of sttistics. Mc Grw Hill Book Co. New York, USA. p Steer, B.T. nd P.J. Hocking Nitrogen nutrition of sunflower (Helinthus nnuus L.): cquisition nd prtitioning of dry mtter nd nitrogen y vegettive orgns nd their reltionship to seed yield. Field Crops Res. 9: Ysin, M., A. Mhmood, A. Ali, M. Aziz, M.M. Jved, Z. Iql, 013. Impct of vrying plnting pttern nd fertilizer ppliction strtegies on utumn plnted sunflower hyrid. Cercetri Agron. in Moldov. (154): Zmn, S.M.H., K. Rhim nd M. Hwlder Simple Lesson from Biometry, Bngldesh Rice Reserch Institute, Gzipur. p Zuillge, M.M., J.P. Aristi nd R.S. Lvdo. 00. Effect of phosphorus nd nitrogen fertiliztion on sunflower (Helinthus nnuus L.) nitrogen uptke nd yield I. Agron. Crop Sci. 188: S. No AUTHORSHIP AND CONTRIBUTION DECLARATION Author Nme Contriution to the pper Mr. Doult Big Mr. Fid Mohmmd Asi Mr. Hi Ahmed Wrote strct, Methodology, Dt entry in SPSS nd nlysis, Result nd discussion, Introduction, References Conceived the ide, Overll mngement of the rticle Technicl input t every step 4. Dr. Mqsood Qmr Did SPSS nlysis 5. Dr. Muhmmd Ayu Khn Dt collection (Received Jnury 015 nd Accepted July 015) 4