Jerusalem artichoke (Helianthus tuberosus L.) originated from the eastern United States and Mexico. Although considerable breeding efforts were made in Europe, the former Soviet Union, and to some degree in Canada, the species remains a neglected crop. Comprehensive characterization data of the genetic resources preserved in different genebanks is rare. A total of 162 Jerusalem artichoke accessions were preserved by Plant Gene Resources of Canada (PGRC) in 2006. This material was agrobotanically characterized in the growing seasons of 2006 and 2008 at Saskatoon, Saskatchewan, Canada. The results of 158 accessions grown in both years were compared. The assessments of variability of 13 rated and 10 measured descriptors for leaf, stem, tuber and phenological characters documented a wide range of phenotypic variation. Repeatability of assessments between the years was generally low, indicating a strong environmental influence on phenotypic diversity. Earliness of flowering, tuber width, tuber weight, tuber shape, tuber epidermis coloration and below-ground growth habit (tubers clustered vs. spread) were the most informative characteristics for describing variation among Jerusalem artichoke accessions. Leaf dimensions and leaf margin serration could also be used to distinguish extreme genotypes. A suggestion for categorizing the PGRC collection into large-tuber and primitive material based on single tuber weight and tuber width is made. Six categories of tuber types based on tuber color and tuber shape are presented.

This present investigation was undertaken to determine some plant characters in six wild Helianthus genotypes and their test hybrids in 2007 and2008. Helianthus petiolaris spp. petiolaris (E-142), Helianthus neglectus (E-017) and four wild Helianthus annuus (E-060, E-173, E-174 and E-175) wereused as the material. The morphological characters observed in the wild Heli-anthus genotypes were plant height, head diameter, lateral number, number ofdays to 50% flowering, flowering period length, and presence of anthocyanin inthe cotyledons. In the second year, test hybrids of E-017, E-142, E-173 and E-175 with the female line 2453-A were evaluated for seed yield, seed weight andsome morphological traits. The results showed that plant height, head diame-ter and lateral number for these wild genotypes ranged from 63 to 171 cm, 2.4to 8 cm and 43 to 324.3, respectively. The wild sunflower genotypes needed82-105 days after emergence to reach 50% flowering and had flowering periodsof 67-91 days. E-142 (Helianthus petiolaris spp. petiolaris) and its test hybridwith the female line 2453A were similarly in the early group for days to 50%flowering. E-017 (Helianthus neglectus) and its test hybrids were similarly latefor days to 50% flowering. Interestingly, although E-173 had medium plantheight, its test hybrid had the shortest plants.

The objectives of this study were to determine self-fertility and restoration capability of cytoplasmic male fertility of some wild sunflower genotypes. The evaluated genotypes were Helianthus petiolaris spp . petiolaris (E-142), Helianthus neglectus (E-017) and Helianthus annuus (E-060, E-173, E-174 and E-175). For hybridization, the female inbred line 2453-A was used. Results showed that self fertility ratios of wild sunflower genotypes varied between 22.4 and 66.1%. The highest level of self fertility was observed in Helianthus petiolaris spp . petiolaris (E-142), while Helianthus neglectus had the lowest values. The E-060 and E-174 genotypes did not restore cytoplasmic male sterility in the hybrids tested.

The objective of this study was to analyze the variability and mutual dependence of the tuber weight per plant, tuber number per plant, average tuber weight and total sugars content in the tubers of 20 Jerusalem artichoke genotypes included in a varietal trial conducted in the period 1994-2008. The variability of tuber weight per plant, tuber number per plant and average tuber weight was significantly affected by environmental conditions, while the total sugars content in the tubers depended primarily on the genotype. As the tuber weight per plant increased, the content of total sugars in the tubers decreased. Maximum tuber weight per plant was achieved with the genotype BT-4 and highest contents of total sugars in tubers were found in the genotypes Violet Rennes, UKR 5/82 and Topianca.

Response of six wild sunflower genotypes including Helianthus petiolaris spp. petiolaris (E-142), Helianthus neglectus (E-017) and Helianthus annuus (E-060, E-173, E-174 and E-175) to drought stress imposed at the seedling growth stage was investigated in vivo . Plant height, number of leaves per plant, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight were determined. Results indicated that the E-175 genotype belonging to Helianthus annuus was less affected by water stress conditions as compared to the other genotypes. Helianthus petiolaris spp . petiolaris (E-142) showed the highest sensitivity and had the lowest fresh and dry masses under drought conditions. In addition, this study showed that the number of leaves and root weight were the best selection criteria to determine drought resistance at the early vegetative stage. Water losses of the resistant genotypes in their roots and shoots in drought stress conditions were more than those of the sensitive genotypes.

Turkey is an important country for plant genetic resources. The conservation of plant genetic resources is important for the sustainable protection of genetic diversity. Because the new uniform and high-yielding varieties used in modern agriculture may cause the erosion of genetic diversity of local varieties or landraces, the collection and characterization of local germplasm becomes necessary. The sunflower ( Helianthus annuus L.) is one of the important oilseed crops for Turkey. Sunflower landraces have significant diversity in Turkey as one of the micro-gene centers for sunflower. For this reason, sunflower landraces are collected within the framework of the National Industrial Plant Genetic Resources Project. These accessions are maintained long-term ex situ at the National Gene Bank and are characterized for better understanding of the eco-geographic variation of sunflower landraces throughout region and for assessing the sustainable utilization of these collections. The eco-geographical distribution of the landraces and agro-morphological variation of the sunflower collection of the National Gene Bank will be presented. The amount of diversity and the genetic resources of sunflower used as a source of morphological similarity or dissimilarity of sunflower genetic resources were analyzed. The sunflower accessions used in this study, which were collected from different sites in Turkey, were evaluated for morphological characters. Ecological differences affect the morphology of sunflower; thus, quantitative aspects of variation were evaluated using plants grown under the same conditions. Multivariate analysis was performed for diversity determination of sunflower and morphometric parameters were examined. The distribution areas of sunflower samples showed great diversity. The distinct groupings were determined in principal components and the results of the analysis exhibited a broad morphological variation model of sunflower landraces.

Sunflower necrosis disease (SND), observed during 1997 in India has now become established in all major sunflower-growing states and has assumed the status of disease of national importance, thereby threathening sunflower cultivation in general. As it is a new disease, reliable resistance sources are still under investigation. A new insecticide thiomethoxam (Cruiser 70 W.S.) was tested for three years at Oilseeds Research Station, Latur (M.S.), India, to manage the necrosis disease in the current sunflower production. The three-year data (2006-2008) revealed that the sunflower necrosis disease can be managed by treating seeds with thiomethoxam at 4 g/kg along with two sprays of the chemical at 0.05% 30 & 45 DAS.

About 65% of sunflower production in Turkey, which is the world’s 11 th largest producer of sunflower based on the FAO data, occurs in the Thrace region. The biggest problem in sunflower areas in the Thrace region is broomrape ( Orobanche cernua L.). Three types of sunflower cultivars are planted in the region, namely hybrids genetically resistant to broomrape (GRH), nonresistant ones (NRH) and IMI (Imidazolinone) herbicide resistant ones (IMIH), which control both broomrape and key weeds in sunflower production. The adoption situation and the performances of these three sunflower hybrid types were studied in the research. The research data was obtained from 571 agricultural enterprises, which were determined based on the Stratified Random Sampling Method in the Thrace region. Sunflower is grown on 42% of the total cultivated land surveyed in the research and accounts for 23% of the total agricultural revenue. The adoption rate and degree of IMIH and GRH sunflower hybrids were calculated to be over 90%. The highest yield (1,915.10 kg ha -1 ) was obtained from GRH hybrids in the research areas. A high yielding potential and easier weed control are seen by the farmers as being among the most important factors for choosing a particular type of sunflower seed. Statistical differences were observed among the sunflower hybrid types based on seed yield, revenue, and seed amounts. The highest net profit was obtained from GRH hybrids in the study. Additionally, based on the results, NRH hybrids were found to be more profitable than IMI hybrids.

Sunflower ( Helianthus annuus L.) is one of the important oilseed crops with a high oil percentage (45-50%) and oil quality. It can be grown in both the first and second crop production seasons in the Aegean Region with high yield capacity. According to the production data of 2008, sunflower was produced on 577,958 ha and 992,000 metric tons of sunflower seed were harvested in Turkey (Anonymous, 2010). Because of the gap in vegetable oil production in Turkey, sunflower is one of the alternative and leading oilseed crops for increasing vegetable oil production. One possibility for increasing this production is for sunflower to also be grown as the second crop in the Aegean Region. The mission of the Oilseed Research Project at the Aegean Agricultural Research Institute (AARI) is to reduce the cost of sunflower production by improving well adapted and high yielding varieties. A number of different approaches are utilized to achieve this goal. Improved germplasm for hybrid development and breeding lines of oilseed and confectionary type of sunflower germplasm (A, B and Rf lines) and also improved populations have been developed by conventional breeding techniques. To improve sunflower varieties with desired characters, genetic investigations and germplasm development of sunflower with improved yield, oil quality, resistance to disease [Sunflower rust ( Puccinia helianthi Schw.)], insect, Orobanche sp., and adverse conditions are under consideration. The research program is aiming to develop oilseed and confectionary type of sunflowers for both the first and second crop production seasons. Sunflower germplasm has been developed from sources such as cultivars, populations created through breeding methods, or inter-specific crosses with wild germplasm and then tested for general and specific combining abilities, oil percentage, and resistance to prevalent disease and adverse conditions to construct improved varieties. For hybrid variety development, combining ability studies in oilseed and confectionary sunflower breeding program were undertaken with line × tester analysis. More than 2000 lines, candidate varieties, and commercial varieties were evaluated in preliminary and yield trials in the first and second crop production seasons. Variety performance tests and yield trials indicated that sunflower can be grown with satisfactory yield performance (approximately 500-550 kg da -1 ) in both the first and second crop production seasons in the Aegean Region of Turkey. Improvement of oilseed and confectionary types of sunflower parental germplasms (A, B and Rf lines) including hybrid and open pollinated varieties has been carried out. The oilseed type of the open-pollinated variety Ege-2001 was developed by the S 0:1 generation testing method (modified recurrent selection) and has been registered. Effects of plant population, planting time, fertilizing, irrigation, and honeybee pollination on seed yield, oil percentage and other plant characteristics and silage quality of sunflower ( Helianthus annuus L.) were determined. Sunflower rust ( Puccinia helianthi Schw.) race identification was performed under field conditions.

Oilseeds are one of the most valuable crops in Turkey’s agriculture and economy as they are the most important source of vegetable oil, feed for livestock and, as of recently, biodiesel feedstock. At the present time, Turkey cannot even meet its own demand for oilseeds, and this problem stems mainly from a lack of planning in the production phase. At present, more than half of the country’s need for oil is s met by imports and the import value of crude vegetable oil and oilseed crops is the second largest figure in the country’s total exchange expenditures, trailing only petroleum products. In the last two decades, although the total oilseeds production has increased nearly 20%, the area planted to oilseeds has gone down by 12%. Among oilseeds, soybean has been hit the hardest, as the area planted to the crop and its production decreased by 80% and 68%, respectively. In the Black Sea region, including the Samsun and Ordu provinces, which used to be the country’s largest soybean producer, soybean areas and production have also decreased drastically. The soybean acreage and production in the Samsun province have dropped by 60% and 18%, respectively. Worse still, in the Ordu province, where the country’s first soybean oil factory was set up in 1965, soybean is not grown anymore. Farmers in the two provinces have started gravitating mostly towards hazelnut production, resulting in a nine-fold and two-fold increase in the Samsun and Ordu provinces, respectively. Sunflower, the major oilseed crop of Turkey, currently provides approximately 50% of the country’s total oilseed supply. Over the years, sunflower production in Turkey has followed an ever-fluctuating course. The situation is even worse in the Central Black Sea region including Samsun, Çorum and Amasya provinces, where sunflower area have decreased by 54%, 53% and 72%, respectively. On the other hand, the self-sufficiency ratio in sunflower consumption has decreased from 70% in 2000 to 38% in 2007. The excessive decrease in the self-sufficiency ratio should be regarded as an alarm bell for sunflower and must be taken seriously without delay if the country does not want to play out the same tragic scenario as in the case of soybean. It should always be kept in mind that strategic planning for the future in most cases depends on past history.

Vegetable oils and fats are vital components of the human diet because they are an important source of energy. In 2008, according to the production data, sunflower was grown in Turkey on an area of 577,958 ha and 992,000 metric tons of the seed were harvested (Anonymous, 2010). Because of the gap in vegetable oil production in Turkey, sunflower is one of the alternatives and the leading oilseed crop that can be used to increase the vegetable oil production in the country. Growing sunflower as a crop in the Aegean Region is one of the possibilities to increase the production. The main objectives of this study were to identify oilseed hybrids and open-pollinated confectionary varieties that could be grown with satisfactory yield performance in the Aegean Region. The experiments including oilseed and confectionary types of cultivars were conducted separately during the first crop-growing seasons of 2008 and 2009 on the experiment field of the Aegean Agricultural Research Institute in Menemen, Izmir. The experiments were conducted in a randomized complete block design with four replications. Oilseed hybrids and open-pollinated confectionary sunflower candidate varieties were used in the study as the material. An adaptation study was undertaken for the characters of seed yield, seed oil content (%), 1000-seed weight, plant height, head diameter, seed length, seed width, hull percentage (%), seed color (white, black, and intermediate), days to flowering, and days to physiological maturity. The results indicated that statistically significant differences were found among the sunflower varieties for the characters in question. In the oilseed variety experiments, the highest seed yield (572 kg da -1 ) and the lowest seed yield (343 kg da -1 ) were obtained in 2009 from the varieties ETAE-Y-TM-2007-5 and Armada, respectively. In the confectionary variety experiments, the highest seed yield (563 kg da -1 ) and the lowest seed yield (202 kg da-1) were produced in 2009 by the varieties ETAE-D1-2-B2 and ETAE-Ç-P-1-2, respectively.

Path coefficient analysis was used to separate direct and indirect effects of studied traits on seed oil content and seed yield, and to identify traits that could be used as selection criteria in sunflower breeding. Significant and highly significant correlations were found between most of the examined traits. Highly significant negative correlations have been established between stem diameter, total leaf area per plant, head diameter and 1,000-seed weight on one side and seed oil content on the other. Highly significant positive correlations have been established between seed yield on one side and stem diameter, total leaf area per plant, head diameter, total number of seeds per head, and the 1,000-seed weight on the other. The weight of 1,000 seeds had a highly significant direct negative effect on seed oil content and a highly significant direct positive effect on seed yield. The total number of seeds per head has demonstrated a highly significant direct positive effect on seed yield and oil content. The total leaf number per plant has demonstrated a significant direct positive effect on seed yield. A path coefficient analysis of seed yield at phenotypic level indicated that maximum direct effects were shownby the weight of 1,000 seeds, total number of seeds per head and total leaf number per plant. The total number of seeds per head was the most important trait that determined seed yield and oil content. The obtained results can be used in sunflower breeding programs aimed at the development of sunflower hybrids that combine high genetic potentials for seed yield and seed oil content.

Sunflower is an important oilseed crop because of its wide adaptability, suitability to mechanization, low labor needs and high protein and oil contents. The present study aimed to investigate the relationship between growing degree days and yield and yield components in different sunflower hybrids and to identify environmental factors and crop characteristics that affect grain yield in sunflower without irrigation in Berlin environmental conditions. The study was conducted in the experiment fields at the Crop Science Department of the Agriculture and Horticulture Faculty of Humboldt University during 2010. The experiment was laid out in a randomized block design, with four blocks of plots of eight Turkish cultivars (Sanbro, Tarsan, DKF-2525, TR-3080, EDR- 08-01, EDR-08-02, EDR-08-03, EDR-08-04) and two German cultivars (Pegasol, NK Delfi). It was determined that the differences among all the sunflower cultivars were statistically significant for plant height, stem diameter, head diameter, 1000 seed weight, dry matter, harvest index, seed yield per plant, seed yield, leaf number, GDD (Growing Degree Daysand sun radiation. The highest mean stem diameter, harvest index and 1000 seed weight were obtained from Pegasol. NK-Delfi had the highest mean head diameter and consequently the highest seed yield (3,876.6 kg ha -1 ), followed by DKF-2525 and Sanbro (3,498.7 and 3412.9 kg ha -1 , respectively). The sunflower cultivars required between 127 and 137 days, 2,263.57°C GDD and 927.54 h sunshine radiation from planting to maturity, as the mean of all the cultivars. Generally, the seed yields of the Turkish candidate genotypes were lower than those of the other sunflower cultivars. The seed yield of these genotypes can be improved with another agriculture method. The rainfall and cold weather in May slowed the growth of sunflower and also the rainfall and cold weather in August delayed maturity. The dry and hot weather in June and July created stress on plants. In terms of seed yield, NK-Delfi, DKF-2525, Sanbro, and Pegasol proved to be suitable sunflower cultivars to be grown in Berlin.

Combining ability studies in oilseed sunflower were undertaken with a set of 5 × 4 line × tester including parents for the characters seed yield, 1000- seed weight, days to flowering, days to physiological maturity, plant height, head diameter, stem diameter, oil content, fatty acid content (oleic, linoleic, palmitic, and stearic acids), protein content, seed length, seed width, and hull percentage. General (GCA) and specific combining abilities (SCA) and heterosis of inbred lines and their hybrids were estimated in a line × tester analysis during the first and second crop production seasons in Menemen, Izmir, Turkey. The variances due to GCA and SCA were highly significant for most of the characters in both environments. The ratio (H/D)1/2 and σ 2 GCA/ σ 2 SCA depicted the preponderance of non-additive type gene action for all the characters except plant height, head diameter, seed length, palmitic acid content, and stearic acid content. However, both types of gene action were observed for seed yield, hull percentage, 1000-seed weight, oil content, and stem diameter at stem curve point. In this study, GCA effects were found to be highly significant for all traits, while SCA effects were non-significant for most of the traits. Based on GCA effects in the first and second crop production seasons, the inbreds 0043 cms , 0046 cms , 0195 cms , 0583 cms , 0704 cms , 0708 Rf , 0845 Rf , 0951 Rf , and 1097 Rf exhibited desirable GCA effects and were found to be good general combiners for most of the traits. Thus, they can be exploited by further breeding for developing superior genotypes and hybrids in sunflower.

Pleiotropic effect of a high pamitic ( p ) and high oleic ( Ol ) mutations in sunflower seed oil was investigated in VK580 near-isogenic lines in field conditions. It was found that the p mutation decreased plant height by 41 cm (32%), number of leaves by 4 (14%) and the period of emergence-flowering by 2 days (4%). The Ol mutation significantly increased plant height by 4 cm (3%). In addition, relationship between inheritance of high palmitic mutation and plant height in the case of selfing of F 2 plants was observed in the cross VK850 ( p ) × VK508 ( Ol ). The correlation coefficient was r=-0.54 with linear equation y=154.49-1.95x. The average plant height of the high palmitic homozygotes in the segregated F 2 population was lower and estimated at 109 cm as compared with 138 cm in the other plants (LSD05=3 cm). Thus, a negative effect of the high palmitic mutation on plant height was proved beyond doubt. A question remains whether this phenomenon relates to a gene linkage or true pleiotropy.

Broomrape ( Orobanche cumana Wallr.) presents a serious problem in sunflower production in a number of countries. The population of broomrape has been stable in Serbia for a long period of time, but the racial composition has changed in recent years, with race E being predominant in the regions of north Bačka and Banat. Cultivated sunflower is genetically narrow and deficient in many desirable genes. Sources of resistance genes to broomrape can be found in a number of wild sunflower species. New 7 Rf inbred lines (RHA-D- 1, RHA-D-2, RHA-D-5, RHA-D-6, RHA-D-7, RHA-D-8, RHA-D-9) were produced from interspecies population originating from H. deserticola (DES-1474-1) in IFVC. The inbreeding of the selected plants from interspecific populations started in 1995 (S 1 ). The first screening of sunflower Rf lines for broomrape resistance was done in a glasshouse in 1999 (S 5 ). The seed from the resistant plants was tested in infested fields, in the area of S. Miletić and B. Topola during 2000 (S 6 ). Selection of resistant plants was checked from 2001 (S 7 ) to 2003 (S 9 ). The same procedure was conducted in Pačir from 2004 (S 10 ) to 2008 (S 14 ) and in the area of Lipar in 2009 (S 15 ). Experimental hybrids were produced by crossing new Rf lines developed from interspecific population (DES-1474-1) resistant to broomrape race E with cms female lines susceptible to broomrape. The resistance of new 28 experimental hybrids to broomrape was checked on locations in Serbia (Pačir 2006, 2007, 2008) and at the location (Lipar 2009) with three controls: hybrid Bačvanin, resistant to race E, hybrid NS-H-111 resistant to race A, B, C, D, susceptible to E race and line AD- 66 susceptible to all broomrape races. The resistance of the same hybrids was also tested at a location in Romania (Baragan, Braila) in 2008. All examined hybrids were resistant to broomrape race E on all locations.

The loss of resistance to broomrape by the majority of domestic and foreign hybrids, that are resistant to the 5 th race of the parasite (E) in the Black Sea and Azov regions of the country indicates that from about 2004-2005 there appeared new (more virulent) races of the parasite ( Orobanche cumana Wallr.). Maternal lines of sunflower hybrids have been developed whose stability to a new race of broomrape is controlled by one dominant gene, Or6 . These lines have a high ability of combination on the main economic grounds.

Sunflower is attacked by more than 40 different diseases of which only a certain number causes serious reduction of seed yield. One of the most damaging diseases is downy mildew, which is caused by the fungus Plasmopara halstedii (Farl.) Berl. et de Toni (syn. Plasmopara helianthi Novot.). Sunflower downy mildew has great economic importance in all countries where sunflower is grown. When the meteorological conditions during the vegetation period of sunflower become favourable for disease development, the damages produce considerable reducing of the seed yield and the oil content. The best way of controlling the fungus is to grow resistant cultivars and because of that the major objective of this study was to develop sunflower genotypes genetically resistant to dominant races of downy mildew in Serbia. During this work two co-dominant CAPS markers for Pl 6 gene were developed which can also be used for Pl 7 gene. For introduction of these genes in breeding program marker assisted selection (MAS) was used. Developed commercial sunflower inbred lines exhibit resistance to all known races of downy mildew in Serbia indicated incorporation of resistance to downy mildew in well-known and widely produced hybrids. Besides that, Pl -genes were introduced to a large number of new inbred lines and new downy mildew resistant hybrids. These new hybrids reach higher seed and oil yields then hybrids widely produced.

Sunflower ( Helianthus annuus L.), with its high oil quality, is one of the major and most valuable oilseed crops in the world. Sunflower rust, caused by Puccinia helianthi Schw., is one of the major foliar diseases of sunflower. The pathogen is present wherever sunflower is grown in the world and causes important yield losses when severe epidemics occur. The objective of this study was to identify the races of sunflower rust under field conditions in the first and second crop production seasons. Experiments were conducted from 1991 to 2009 at Menemen, Izmir - Turkey. Race identification of P. helianthi was accomplished in field conditions in which seedlings of differential lines were naturally infected. Twenty-three differential genotypes were used to identify races of P. helianthi . Sunflower rust reactions of the differential genotypes were scored on a scale of 0 to 4, where 0 to 2 = resistant, 3 and 4 = susceptible. Races 1 and 3 of P. helianthi , the causal agent of sunflower rust, were identified at Menemen - Izmir.

In the present study, thirteen SSRs (Simple Sequence Repeats) were employed for screening the level of similarity between sunflower parental lines and progeny obtained in final stages of selection. Another aim of the study was to compare the success of making isogenic lines through selection. Line P (donor line) was used as a donor of downy mildew gene Pl 6 and backcrossed with four commercial inbred lines (A, B, C and D) susceptible to downy mildew. HAP3, a DNA-specific primer, was used to test the success of transfer of P l6 gene from the donor line to the progeny lines in the Pl 6 and Pl 7 generations. It was found that all progeny lines were resistant to downy mildew. Results obtained by using thirteen primers showed that progeny lines were similar to their respective recipient parent, but further studies have to be conducted using a larger number of primers and a larger number of genotypes.

Hybrid sunflower seed, regularly protected with chemicals, is used for sowing in the second or the third year if not used in the first year after production. In that case, it is stored in warehouses, and the length of storage period may significantly affect the quality of seeds. An experiment was conducted in Laboratory for Seed Testing of Institute of Field and Vegetable Crops in Novi Sad, in order to examine the effect of storage period on germination of treated sunflower seeds of three commercial hybrids of the Novi Sad Institute. The seed was treated with fungicides - metalaxyl and fludioxonil, as well as with insecticides - thiamethoxam and imidacloprid, while untreated seeds served as control. The sowing was repeated throughout the year, at three-month intervals. The obtained results indicated that, on average, the hybrid Sremac had the highest (94.61%), and the hybrid Šumadinac the lowest seed germination (90.29%). After one year of storage, seed germination declined significantly. All three hybrids treated with fungicides and the control had a significantly higher germination than hybrids treated with insecticides. This regularity was not evident right after the treatment - it became noticeable during the storage.

This research was carried out to determine the seed yield and some yield components of two dwarf hybrids as compared to one standard-height sunflower hybrid ( Helianthus annuus L.) at different nitrogen rates and planting densities. The study was carried out under natural rainfed conditions at the Thrace Agricultural Research Institute in Edirne-Turkey between 1999 and 2001. The experiments were set up in split-split plots in a randomized complete block design with three replications. The main plot treatments were three different-height sunflower hybrids, DW-1, DW-2, and Trakya-80. The sub plots were three levels of nitrogen, 0, 60, and 120 kg N/ha. The sub-sub plots were three planting densities, 10 × 70 (142,850 plants/ha), 15 × 70 (95,230 plants/ ha), and 20 × 70 cm (71,430 plants/ha). Based on marginal economic analyses, the economically optimal seed yield per hectare was obtained at 50 kg N/ ha for DW-1 and at 80 kg N/ha for DW-2 and Trakya-80. In all three hybrids, increasing plant densities decreased 1000-seed weight, hull percentage, and head diameter but increased test weight in natural rainfed conditions. The highest seed yield in both dwarf hybrids was obtained with the spacing of 15 × 70 cm (95,230 plants/ha). The results of this research show that nitrogen and plant density have significant effects on seed yield and some yield components of different-height sunflower hybrids.

Although boron is essential for crop growth, the amount required differs among plant species. Sunflower ( Helianthus annuus L . ) requires greater quantities of boron to satisfy its metabolic needs than other cultivated species. The present work was undertaken to evaluate what effects five boron doses of 0, 2.5, 5.0, 7.5 and 10.0 kg B ha -1 (applied as a spray of boric acid, H 3 BO 3 ) would have on micronutrient contents in leaves of four sunflower cultivars grown in B-deficient calcareous soils (0.19 B mg kg -1 ) during the 2001 growing season. Boron (B), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) concentrations were measured in sunflower leaves at the flowering stage. According to the results, the B concentration in the leaves was highly correlated with boron doses, that is, the leaf B content increased in accordance with increasing B doses applied to the soil. Fe, Mn, Cu, and Zn concentrations in the leaves were not changed by the different B levels. However, leaf Mn, B and Cu concentrations varied with the cultivars. Among the cultivars, TR-4098 had the highest Mn (90.74 mg kg -1 ) and Cu contents (45.95 mg kg -1 ), while AS-615 had the highest B (83.52 mg kg -1 ) and Fe (202.55 mg kg -1 ) concentrations.

We studied minimum tillage methods suitable for sunflower growing. By selecting and combining appropriate methods, we simultaneously increased the competitiveness of sunflower agrocoenoces against weeds and sunflower yield. Sunflower sowing after wheat at a row spacing of 22.8 cm increased the yield of the hybrid Zaporozhskiy 14 by 0.07-0.19 t/ha after regular plowing and by 0.10-0.12 t/ha after anti-erosion tillage as compared with the sowing at a row spacing of 70 cm.