EFFECT OF AGRONOMIC AMENDMENTS ON GROWTH AND YIELD OF SUNFLOWER

Proper planting geometry helps in obtaining optimum plant population and crop yield, whereas irrigation at adequate time intervals result in improved crop yields and quality of the produce. Considering the same, two years field experiments were conducted during 2019 and 2020 at Tandojam to examine the effect of sowing methods (Raised bed, Ridge, Drilling and Broadcasting), planting densities (recommended, high density and ultra-high density) and nutrient management (90+60+60+0, 90+60+60+10 and 90+60+ 60+20 kg ha -1 N±P±K+FeSO 4 ) on growth and yield parameters of sunflower. The experimental design was a randomized complete block design with three replications. Best result in all parameters on average factors including drilling method, high density planting (66,666 plants ha -1 ), NPK+FeSO4 =90+60+60+20 kg ha -1 and their interaction resulted in economically superior overall sunflower performance in relation to its growth, seed yield and quality attributes. The drilling method was highly effective to improve seed yield apart from the lower biological yield due to greater harvest index as compared to rest of the sowing methods. Although, recommended plant spacing (55,555 plants ha -1 ) produced better individual plant based results, but due to lesser plant population, the overall seed yield was greater under high density planting (66,666 plants ha -1 ). Ultra-high density plantation (83,333 plants ha -1 ) did not prove beneficial due to crowded plant population where harvest index became poor despite an increased biological yield. Higher FeSO 4 improved the grain quality and no effect on foliage; hence 20 kg FeSO 4 remained economically most beneficial to achieve desired seed production.


Introduction
Pakistan's yearly import bill of crude edible oils is approximately US$ 3.4 billion metric tons, apart from the agrarian national economy.In 2020-21, palm and soybean oil up 5% from the previous year.Palm oil remains the major imported oil, while oilseed imports are projected at 3.3 MMT, up 6%.The import bill of edible oils and oilseeds shows a diminishing trend in 2019-20 in the first half of 2020-21 probably due to soft international prices and increased local output of oilseeds as well as improved efficiency of the domestic edible refining industry.However, the increase in cooking oil and vegetable ghee production is entirely associated with a rise in local oilseeds production, particularly at a time when policies of the government are causing a contraction in imports (Rana et al., 2022).The major sunflower-growing countries are Russia, Ukraine, Argentina and European nations.Only Russia and Ukraine produce half of the total world sunflower production (FAO, 2019).According to the FAO (2019), globally, the sunflower was cultivated on 26 million hectares, and 45 million metric tons of sunflower seed was produced worldwide in the year 2019, while the seed yield produced in Pakistan is only 1274.7 kgs.According to the Pakistan Economic Survey, 2019-20 during July-March, 2.748 million tons of edible oils were imported spending US$ 2.046 billion, while during this period the local edible oil production remained 0.507 million tons.During 2019-20 in Pakistan, the sunflower was cultivated on an area of 219 thousand acres, receiving seed production of 105 thousand tons and oil production of 40 thousand tons (GoP, 2020).
Sunflower (Helianthus annuus L.) is a potential oilseed crop that can bridge the gap between consumption and supply of edible oil in Pakistan (Nezami et al., 2008).However, there is still a huge gap between the achieved and potential yields of sunflower, and this happens only because of the nonadoption of recommended agronomic practices including application of nutrients without considering the optimum rate of these inputs, low or no use of micronutrients, traditional methods of growing crop; non-adoption of new sunflower varieties possessing high yielding characteristics that have resistance against various biotic and abiotic factors (Ullah & Hussain, 2010).Among the factors associated with successful crop cultivation, the sowing of crops using appropriate methods is of great importance to achieve desired crop yields as the sowing method has a significant impact on crop growth and subsequent yields (Zhangzhong et al., 2018).The growers with small land holdings generally adopt traditional methods of sowing, while the progressive growers use relatively improved production practices, because they have easy access to awareness of the advanced crop production technologies (Ahmad et al.,2000;Cucci et al., 2017).Traditional sowing methods include broadcasting manually, opening furrows by a local plough dropping seeds by hand and dropping seeds in the furrow through a bamboo/metal funnel attached to a plough.For sowing in small areas dibbling is practiced.Multi-row traditional seeding devices with manual metering of seeds are quite popular with experienced farmers (Hussain et al., 2000;Vijayakumar & Ramesh, 2005).Traditional sowing methods have various limitations.In manual seeding, it is not possible to achieve uniformity in the distribution of seeds.A farmer may sow at the desired seed rate but the inter-row and intra-row distribution of seeds is likely to be uneven resulting in bunching and gaps in the field; poor control over the depth of seed placement; it is necessary to sow at high seeding rates and bring the plant population to desired level by thinning (Shariti & Amin, 2003;Pereira & Hall, 2019).The main aim of this study was to evaluate the influence of different sowing methods, planting density, and fertilizers on the growth, yield and oil content of sunflower.

MATERIAL AND METHODS
Field experiments were conducted for consecutive two years at the Oil Seeds Research Institute, Agriculture Research Centre Tandojam during 2018 and 2019.Various growth and yield performances (quantitative and qualitative traits) of sunflowers were investigated under the influence of different sowing methods, planting density and fertilization (NPK+FeSO4).The experiment was arranged in a randomized complete block design with three-factor combinations replicated thrice.The area of each replicated experiment combination plot was 30 m 2 (6 m x 5 m).The analysis of soil was performed before sowing and after harvesting.The research study consisted of four different sowing methods (Raised bed, Ridge, Drilling, Broadcasting), four planting density [Recommended density =30 cm or 55,555 plants ha -1 or 5.56 plants m -2 ), High density = 25 cm or 66,666 plants ha -1 or 6.67 plants m -2 ), Ultra density = 20 cm or 83,333 plants ha -1 or 8.33 plants m -2 )], and three fertilizer levels (NPK at 90+60+60 kg ha -1 , NPK+FeSO4 at 90+60+60+10 kg ha -1 , NPK+FeSO4 at 90+60+60+20 kg ha -1 ), using HO-1 sunflower variety.Sowing was done through hand drill in ridges and drilling methods while broad casting was done in raised bed and broad casting methods.Thinning was done to maintain optimum plant distance.A total of five irrigations were applied at 15 days interval.The N, P, and K were applied at 90, 60 and 60 (kg ha -1 ) and FeSO4 (10+20 kg ha -1 ) from Urea, SSP and SOP sources, respectively.The application of N was in three equal splits; i.e. 1 st at planting time, 2 nd at 1 st irrigation (15 DAS) and 3 rd at 3 rd irrigation (45 DAS).All phosphorus and potassium were applied at the time of land preparation.Inter-culturing was done for controlling weeds before 1 st , 2 nd , and 3 rd irrigations, respectively.

Statistical analysis:
The collected data was subjected to Analysis of Variance (ANOVA) using STATISTIX ver.8.1 computer software (Statistix, 2006) where P values less than 0.05 were considered statistically significant.The Least Significant Difference (LSD) test was applied to compare treatments superiority.

RESULTS AND DISCUSSIONS
Seed Germination (m -2 ): The data pertaining to seed germination of sunflower under the influence of various treatment combinations are provided in Table 1.The statistical analysis described that the germination percentage of sunflower was significantly (P<0.05)influenced by different sowing methods, planting densities, and fertilizer levels.The germination would have little or no response to the treatments, because the planting densities were dependent on seed rates; and high or ultra-high densities correspond to high seed rates were used to get more seedlings.Ahmad et al. (2000) argued that although the final crop stand has significant association with nutrient and crop management, but at germination, only soil and climatic conditions play vital role including seed viability.Similar results have been reported by Ahmed et al. (2011) who also found improved crop presence and absence of FeSO4 had a vital impact on germination and this impact was proportional to the dose of application in addition to NPK recommendation.Drilling proved to be more advantageous sowing method as compared to raised bed, ridge sowing or broadcast method.However, germination is a typical parameter and little is associated with the sowing patterns; but factors that affect aerial and soil environment could be more influential to germination.Akbari et al. (1999) and Ali (2008) experienced that seed germination is significant association with the soil type, soil available nutrients and climatic conditions, and in the present study, only basal fertilizer dose could influence this crop characteristics.Ahmed et al. (2011) Moreover the entire plots in the experiment were supplied with similar NPK combination, but difference was the application of FeSO4 and this nutrient may have apparent effect after seedling development, growth, and crop yield production levels, but the data did not show a linear impact of cropping patterns or nutrient management including iron sulphate application on germination level of sunflower

Plant height (cm):
The plant height remained superior in drilling sowing method with high planting density (25 cm plant spacing) and when the crop supplied with N+P+K+FeSO4 @90+60+60+20 kg ha -1 (181.30cm).Ali et al. (2011) found that taller plants (178 cm) were observed in Hysun-33 with optimum row spacing of 75cm followed by the same hybrid (177.5 cm) with narrow row spacing of 55 cm (Khan et al., 2011).The use of secondary nutrients (FeSO4) showed high economic results suggesting growing soil deficiency for this element.Drilling method proved to be far better than raised bed, ridge sowing or broadcast methods as evident from the results.Hussain et al. (2000); Vijayakumar and Ramesh (2005) found that plant growth was significantly affected by sowing patterns and seed drilling showed its superiority and tallness of the plants were greater in drilling method as compared to other sowing techniques.The results of the present study are further confirmed by Badiyala and Chopra (2011) who have reported that nutrients availability in soil as per the crop requirement is of prime significance and secondary elements including iron and zinc deficiency in soil may sometimes constrain the crop from potential growth.Bameri et al. (2012) found that application of micronutrients improves crop growth optimally.Stem girth (cm): Sunflower stem girth was greater in drilling method (6.53 cm), followed by ridge method (6.47 cm) and raised bed method (6.41 cm); while in broadcast method, the produced plants had least stem girth (6.33 cm).This greater stem thickness under drilling method of sowing was mainly associated with better ventilation and adequate availability of nutrients due to proper and uniform spacing between rows.In broadcast method, the plants could not intercept sunlight, resulting the reduced development of the stems.The studies carried out by Shariti and Amin (2003) and Pereira, & Hall (2019) concluded that in drilling sown sunflowers, the stems of plants were found stronger and thicker as compared to broadcast method or any other sowing technique.In case of increased planting density beyond the recommendations, the plant population was increased substantially, and hence with increasing plants competition for attaining natural resources and applied inputs more sharing of inputs caused to decrease stems' girth.Thus, 30 cm plant spacing which is already recommended by the agriculture scientists for sunflower was found to be better than rest of the planting densities, however, examination of such impacts on yield traits should be carefully considered.Moreover, addition of FeSO4 at the higher rates of 20 kg ha -1 remained quite beneficial for sunflower when added to NPK at recommended rate.So treatment interaction of drilling sowing method, 30 cm plant spacing and N+P+K+FeSO4 @90+60+60+20 kg ha -1 remained superior treatments for stem girth (7.05 cm).Similar results have also been reported by Bansal and Chahal (1990) and Pereira & Hall (2019) reported that Fe application in addition to NPK recommended fertilizers results in stronger crop stems to optimize crop performance from yield point of view.Ballare and Casal (2000) described that due to wider spacing and less plant population in recommended density, the average share of plants for inputs and natural resources increased and hence better ventilation caused positive impact to grow vigorous plants.Shariti and Amin (2003) found that with increasing planting density, the allocated share of the average plant for nutrients, other inputs and natural resources.Johnson et al. (2010) and Pereira, & Hall (2019) reported that the thicker stems in sunflower ensure the plants to establish bigger seed head to produce more seed rows.Similarly, FeSO4 application resulted in encouraging results in regards to stem thickness, because there is interrelationship of stem thickness with the yield contributing traits.In sowing methods, drilling showed more encouraging results in regards to stem girth as compared to rest of the methods tested Boorboori et al. (2012).

Head diameter (cm):
The head diameter was desirable under drilling method (24.81 cm), followed by ridge method and raised bed method, while in broadcast method the head size was found to be the least.Drilling method proved to be more effective produce seed heads with bigger size than rest of the sowing methods.Probably, aeration due to proper line sowing, easy interception of light and adequate reception of soil moisture and nutrients was the major advantage to the plants sown through drilling method over other seedling techniques.These results are in agreement with those of Johnson et al. (2010) who concluded that drilling sown sunflowers resulted in greater head size and under this sowing technique the plants get optimally greater share of nutrients from the soil and utilize natural resources from the environment.The increasing planting density caused increased plant population, more competition among plants to grow vigorously, while under 30 cm plant spacing due to lowest plant population, the plants experienced better utilization of applied inputs and natural resources.In case of nutrients management, NPK+FeSO4 @90+60+60+20 kg ha -1 resulted in maximum head size (25.01 cm) and addition of FeSO4 at the higher rates of 20 kg ha -1 remained effective to improve head size when added to NPK at recommended rate.These results contrast with those of Diepenbrock et al. (2001), who achieved better crop growth and head size.However, the ecology of the research might differ from the location of the present research.Thus, treatment interaction of drilling method sown with NPK+FeSO4 @ 90+60+60+20 resulted in biggest sunflower head size.Boorboori et al. (2012) reported that application of Fe in addition to NPK fertilizers resulted in improved seed heads.Bybordi and Malakouti (2003) found that the seeds number increased markedly when the crop received iron and other minerals used to fortify the applied macronutrients.There was a great impact of row direction on sunflower head size; probably North-South row direction improved the crop ventilation to intercept more soil and environmental natural resources over the East-west row orientation.The test of secondary element (FeSO4) on head size remained quite encouraging and head diameter considerably improved over the control.It could be concluded that for achieving a desirable head size in sunflower, the crop needs to be sown with North-south row orientation; the straight fertilizers should be fortified with secondary elements; and better to use drilling method for sowing the crop in lines.Seed weight head -1 (g): The drilling sown crop maximized seed weight head -1 , followed by ridge method (g), and raised bed method (g), while in broadcast method the seed weight head -1 was minimum (g).The treatments based on nutrients management suggested that NPK+FeSO4 @90+60+60+20 kg ha -1 maximized seed weight head -1 (80.35 g) and treatment interaction of drilling method with 30 cm planting density supplied with N+P+K+FeSO4 @90+60+60+20 kg ha -1 maximized seed weight head -1 upto 86.12 g.Kurilcik et al. (2008) reported that the drilling sown crop grew more vigorously probably due to optimum aeration and adequate moisture and nutrients consumption because of allocated space between the lines.The research findings reported by Ahuja et al. (2003) and Shariti and Amin (2003) from India found that sunflower sowing by drilling and maintaining plant stand after thinning showed significantly better results in relation to growth and yield parameters.
Similarly, the wider plant spacing decrease planting density which facilitated plants to obtain increased share from soil and atmosphere, while in decreased plant spacing plant population was increased and the available resources were depleted for individual plants.
Another addition of FeSO4 (20 kg ha -1 ) proved beneficial for achieving greater seed weight head -1 that necessitates the research to assess the soil availability of other nutrients apart from the commonly used soil fertilizers.The above results are in concurrence to those of Duraisamy and Mani (2001); Ebrahimian and Bybordi (2011) and Gaffar et al. (2011) who reported that application of micronutrients including Fe as fortification of recommended macronutrients proved to be beneficial for crop production and produce quality.
The soil organic matter was also found improved after soil applied micro nutrients.This higher seed weight head -1 under this treatment combination was chiefly linked with improved head size and more seeds head -1 that in the end produced healthier seeds and hence greater seed weight head was achieved.Ebrahimian and Bybordi (2011) and Gaffar et al. (2011) found that the drilling sown crop intercept the natural resources from the soil and environment and grew vigorously as compared to other methods of sowing and generally that not only optimize aeration to the plants, but adverse effect of natural hazards is also minimized.Seed index (1000-seed weight, g): Sunflower sown by drilling produced higher seed index value (64.57g) than rest of the methods, and 30 cm planting density maximized seed index (67.23 g), while NPK+FeSO4 @90+60+60+20 kg ha -1 produced highest seed index value (65.09 g).Similar results have also been reported by Anwar et al. (2010) who were of the opinion that except broadcast seeding, all sowing methods produced satisfactory results regarding the seed index, but drilling method was more effective than other methods of sowing to produce quality seed.Usman and Perveen (2004) revealed that hybrid 65A24 showed high and stable yields among the hybrids under drilling method sowing as compared to broadcast.Siddiqui et al. (2009) reported that sunflower cultivars under drilling method had better growth compared to other sowing methods.Soomro et al. (2005) and Soleymani (2017) also reported that sunflower cultivars under the drilling method recorded better growth and heavier seeds compared to other sowing methods.In case of planting density regardless of other parameters that contribute yield ha -1 , 30 cm spacing resulted in heavier seeds than the seed obtained from plots sown with rest of the planting densities.The addition of FeSO4 at higher rate (20 kg ha -1 ) showed more positive results on this trait as compared to its lower rate (10 kg ha -1 ) in addition to NPK fertilizers, which suggested that apart from the macronutrients, the soil may also be amended with micronutrients and other secondary elements to achieve the desired crop yields and seed quality in sunflower.Gangadhar et al. (1992)  Biological yield (kg ha -1 ): The biological yield in broadcast method resulted in more biological yield (11513 kg) than rest of the methods; while NPK+FeSO4 @90+60+60+20 kg ha -1 resulted in highest biological yield ha -1 (11705 kg).The results of this study are in similarity with those of Pandey et al. (2013) who concluded that sowing method plays a vital role in production of field crops, It was further observed that broadcast sown crop produced more foliage as compared to systematic line sowing methods, while drilling sowing method produced least foliage.The dense plant population caused remarkably more foliage than the low-density plantation.The addition of FeSO4 at higher rate of 20 kg ha -1 did not produce higher foliage but FeSO4 at 10 kg ha -1 produced more foliage and hence increased biological yield ha -1 was occurred.The validity of these results could only be recognized if the harvest index simultaneously follows this trend of effectiveness.The application of Iron sulphate (20 kg ha -1 ) did enough to improve foliage but FeSO4 at 10 kg ha -1 produced relatively lower amount of foliage and hence decreased biological yield ha -1 over higher FeSO4 level.Similar results have also been reported by Habib (2012) and reported that supplementary nutrition with Fe and Zn showed marked positive impact growth and foliage of the crop.Khan et al. (2009) supplied sunflower with zinc and iron under irrigated conditions and found increased total biomass yield over control.Kumar et al. (1993) from India reported positive impact of iron on total crop biomass yield.In another study, Kumawat (1999) found that iron supplementation resulted in improved crop biomass yield; while Khushwaha (1999) found soil deficiency of Fe and suggested its soil amendment to achieve potential crop yields.Seed yield (kg ha -1 ): The treatment interaction of drilling method of sowing × 25 cm planting density × N+P+K+FeSO4 @ 90+60+60+20 kg ha -1 maximized seed yield upto 3058 kg ha -1 , while in row orientation interaction.This suggested that drilling method was found to be highly effective to produce higher seed yield apart from the lowest biological yield due to greater harvest index as compared to rest of the sowing methods.Hingoro (2008) reported that sunflower sown on ridges resulted in greater seed under value (15.50, g), seed yield (2311.26 kg per ha) and oil content (40.01%).The studies of Rahimzadeh and Mirak (2009) concluded that sunflower crop under drilling method showed better overall yield performance.Ali et al. (2011) also found that taller plants (178 cm) were observed in Hysun-33 with optimum row spacing of 75cm followed by the same hybrid (177.5 cm) with narrow row spacing of 55 cm (Khan et al.,2011).Baghdadi et al. (2014) reported highest seed yield (2489 kg ha -1 ) from the early planting date at the 75 cm ×20 cm plant spacing.In a recent investigation, maximum crop yield was obtained under drilling method of planting with thinning space.Therefore, it was suggested to the farmers to go for adoption of drilling planting only if labor was available for the thinning (Sharma et al., 2017).Phuhong et al. (2005) found superiority of broadcast seeding in terms of yield; while in the present study, drilling sowing method proved to be better than any other method.This indicates that the above researcher must have different ecology and wind direction or wind velocity as compared to the location of the present study.On the other hand, broadcast method of sowing produced more dry mass than seeds yield.Results of raised bed and ridge sowing were also encouraging and better than broadcast method so far, the grain yield was concerned.Khan et al., (2011) described that the 30 cm plant spacing (55,555 plants ha -1 ) produced better individual plant-based results, but due to lesser plant population, the overall seed yield was higher when high density planting was done, where 25 cm plant spacing was maintained with a population of 66,666 plants ha -1 .However, ultra high density plantation at 20 cm plant spacing (83,333 plants ha -1 ) did not prove beneficial due to crowded plant population where harvest index became poor but biological yield increased.(Sharma et al., 2017) described that the addition of FeSO4 at higher rate of 20 kg ha -1 remained highly beneficial to improve seed yield, against biological yield trait where FeSO4 at 10 kg ha -1 produced more foliage.Hence, higher FeSO4 improved the grain quality and no effect on foliage, hence under greater harvest index, 20 kg FeSO4 remained economical and highly for sunflower seed production.It was concluded that drilling surpassed all rest of the sowing methods in seed yield while biological yield was highest under broadcast method.FeSO4 addition at 20 kg ha -1 to recommended NPK encouragingly improved seed yield as compared to control.Mahriya (1997) reported beneficial effect of iron on the crop yields and mixed with soil applied phosphorus.Majumdar and Singh (2000) analyzed soil deficiency of iron and recommended Fe based fertilizers application in addition to NPK for obtaining higher crop yields.In another investigation, Meena et al. (2006) used a combination of iron, zinc and Sulphur in addition to NPK fertilizers on oilseeds and reported increased yield and benefit cost ratio over control.Muhammed et al. (2006) achieved greater crop production when the crop supplied with iron in addition to common fertilizers over control.Moussavi-Nik et al. (2012) reported from Iran that micronutrient application has shown positive impact on crop seed quality and resulted in higher crop yields when given in addition to regular NPK fertilizers.Qing et al. (2011) investigated the effect of combined application of iron and zinc and achieved improved yield and quality of the crop produce.

Harvest index (%):
The treatment interaction based on of drilling method of sowing, high density planting (25 cm plant spacing, 66,666 plants ha -1 ) and N+P+K+FeSO4 @ 90+60+60+20 kg ha -1 maximized harvest index upto 27.41 percent.Baghdadi et al. (2014) reported highest seed yield (2489 kg ha -1 ) and harvest index (18.93%)from 75 cm ×20 cm plant spacing under drilling method of sowing.It is evident from the results that drilling sown crop remained highly economical to produce higher harvest index as compared to rest of the sowing methods, while broadcast method was found to be the least productive.Under high density planting, the harvest index was greater than planting densities of 83,333 (ultra-high density) or 55,555 plants ha -1 (recommended density) urging to increase plant population upto 66,666 plants ha -1 over 55,555 plants ha -1 planting density.The FeSO4 addition at 20 kg ha -1 proved to be effective with significant improvement in harvest index indicating that FeSO4 had direct impact on seed rather than to effect crop foliage.Similarly, the interaction of NPK+FeSO4 @ 90+60+60+0 and drilling sowing method resulted in harvest index of 27.28 percent.(Jaya et al., 2001).Higher temperature within-canopy due to more direct penetration of radiation.Rise in temperatures reduces period from visible bud to flower development (Yu et al., 2002).The above results did not support the trend of results in the present research.Such differences in findings might be associated with the harvest index is calculated on the basis of seed yield as percentage of the biological yield, and in this regard, the treatment variables interrelate differently.So, only on the basis of harvest index, the treatment superiority cannot be examined but critically examined the seed yield response to these treatments.However, probably soil inadequacy in secondary elements such as FeSO4 needs to be rectified along with other elements.Naga (2005) applied zinc and iron under irrigated agriculture conditions and reported better growth and harvest index over control.Ravi et al. (2008) Sharma (2006) reported improved crop seed quality and harvest index due to application of iron sulphate.However, it is doubtless that north-south row orientation is more effective than anyone else; while would be pertinent if drilling method is adopted on normal irrigated soils to facilitate the inter culturing practices and for achieving quality seeds Shahrokhi et al. (2012).

Oil content (%):
The interactive effect of drilling sowing method, high density planting (25 cm, 66,666 plants ha -1 ) and N+P+K+FeSO4 @ 90+60+60+20 kg ha -1 maximized oil content (41.39 %).The results highlighted that the differences in oil content between drilling, ridge and raised bed methods were marginal, but these differences were wider when compared with broadcast method.Hingoro (2008) reported that sunflower sown on ridges resulted in heavier seeds (15.50 g) and seed yield (2311.26 kg ha -1 ) and oil content (40.01%).Due to wider spacing in low density planting, the oil content in sunflower seed was relatively higher under 30 cm spacing (55,555 plants ha -1 ) and the oil content followed a certain decline with increased planting density.The FeSO4 addition at 20 kg ha -1 showed great positive impact on oil content of sunflower and with decrease in FeSO4 or in its absence the oil content in seed followed a certain decrease.
Similarly, interaction based on NPK+FeSO4 @90+60+60+20 and drilling method resulted in higher oil content in sunflower.Working on the similar aspects, Singh et al. (1995) applied iron in addition to zinc and potassium to fortify existing nutrients and reported that iron supplemented improved crop seed quality, while Singh (2008) reported worldwide micronutrient deficiency of soils.Singh et al. (1993) also reported that ferrous sulphate application improved crop nutrient content.Some other studies such as Singhal and Rattan (1999), White and Broadley (2005), Yadav (2002), and Zareie et al. (2011) concluded that in oilseed crops, the application of micronutrients including iron resulted in significant improvement in seed quality and oil contents.The oil content being a most crucial sunflower trait was markedly influenced by different treatments including nutrient management and sowing methods.The seed obtained from the crop sown by drilling remained superior in oil content.Besides, crop response to FeSO4 reflected the need to rectify inadequacy of secondary elements in the soil.

CONCLUSION AND RECOMMENDATIONS
The results suggested that Drilling method of sowing sunflower may preferably be employed.High density planting based on 25 cm plant spacing, 60 cm row spacing (66,666 plants ha -1 , 6.67 plants m -2 ) proved to be better than recommended density of 30 cm plant spacing (55,555 plants ha -1 , 5.56 plants m -2 ) in relation to yield attributes, and farmers may adopt high density plantation to achieve better returns from sunflower crop.

Table : 9. Seed yield (kg ha -1 ) of sunflower as affected by sowing methods, density and fertilization
Shahrokhi et al. (2012)lar results that are clearly in line with the findings of the present study.Shahrokhi et al. (2012)used foliar spray of iron sulphate and reported improved harvest index due to heavier crop seeds.