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In saline conditions, establishing healthy seedlings is crucial for the productivity of sunflowers (Helianthus annuus L.). Excessive potassium (K+) from irrigation water or overfertilization, similar to sodium (Na+), could adversely affect sunflower growth. However, the effects of salt stress caused by varying K/Na ratios on the establishment of sunflower seedlings have not been widely studied. We conducted a pot experiment in a greenhouse, altering the K/Na ratio of a soil solution to grow sunflower seedlings. We tested three saline solutions with K/Na ratios of 0:1 (P0S1), 1:1 (P1S1), and 1:0 (P1S0) at a constant concentration of 4 dS m−1, along with a control (CK, no salt added), with five replicates. The solutions were applied to the pots via capillary rise through small holes at the bottom. The results indicate that different K/Na ratios significantly influenced ion-selective uptake and transport in crop organs. With an increasing K/Na ratio, the K+ concentration in the roots, stems, and leaves increased, while the Na+ concentration decreased in the roots and stems, with no significant differences in the leaves. Furthermore, an excessive K/Na ratio (P1S0) suppressed the absorption and transportation of Mg2+, significantly reducing the Mg2+ concentration in the stems and leaves. A lower leaf Mg2+ concentration reduced chlorophyll concentration, impairing photosynthetic performance. The lowest plant height, leaf area, dry matter, and shoot/root ratio were observed in P1S0, with reductions of 27%, 48%, 48%, and 13% compared to CK, respectively. Compared with CK, light use efficiency and CO2 use efficiency in P1S0 were significantly reduced by 13% and 10%, respectively, while water use efficiency was significantly increased by 9%. Additionally, improved crop morphological and photosynthetic performance was observed in P1S1 and P0S1 compared with P1S0. These findings underscore the critical role of optimizing ion composition in soil solutions, especially during the sensitive seedling stage, to enhance photosynthesis and ultimately to improve the plant's establishment. We recommend that agricultural practices in saline regions incorporate tailored irrigation and fertilization strategies that prioritize optimal K/Na ratios to maximize crop performance and sustainability. [ABSTRACT FROM AUTHOR]

Imidacloprid, one of the latest members of the neonicotinoids, is a widely used synthetic organic insecticide. In this study, it was aimed to reveal the effects of 2 ppm, 4 ppm, and 8 ppm imidacloprid on antioxidant enzymes and lipid peroxidation in Helianthus annuus L. Tarsan-1018 oilseed sunflower leaves. As a result of the applications, sunflower leaves were collected and frozen in liquid nitrogen, then stored at -40 °C until analyses were conducted. Sunflower seeds were a registered variety and were obtained from Trakya Agricultural Research Institute. Imidacloprid were applied as foliar to the Sunflower plant grown under controlled conditions and samples were taken at 24. 48. and 72. hours. Superoxide dismutase (SOD), catalase (CAT), glutathione s-transferase (GST), glutathione (GSH), oxidized glutathione (GSSG) and malondialdehyde (MDA) analyzes were performed in the samples taken after the applications. As a result, it was determined that imidacloprid had different effects on the biochemical parameters of sunflower plant leaves. It was understood that imidacloprid used in ppm doses stimulated antioxidant defense and created stress responses in the plant, and as with all plant protection products, the importance of proper dosage and controlled use must not be overlooked. [ABSTRACT FROM AUTHOR]

Sunflower is considered a plant with extraordinary adaptability. However, the conditions of growing sunflower function as a limiting factor in its production. The hybrids used in production tolerate weather variability to a different level and utilise the nutrient and water resources of the soil, while the yield is also affected by the number of plants per hectare. In this study, the authors attempted to observe the environmental effects influencing sunflower cultivation, the heterogeneous productivity zones of the given production site and the correlation of the number of seeding plants used under various farm practices. The average rainfall of 2021 and the dry weather of 2022 created suitable conditions for examining the yearly weather effect. In the selected experimental areas, three distinguishable zones were defined in terms of productivity. In each productivity zone, three crop density steps were used in four replicates. Based on the performed comparative tests, the rainy year of 2021 resulted higher yield than the drier year of 2022 in the average- and high productivity zones, while in the low-productivity zone, higher yields were harvested under the drier conditions of 2022 than in the rainy year of 2021. In 2021, with the improvement in productivity, the obtained yield was also higher. However, in 2022, this clarity could not be demonstrated. In the zones with low productivity, identical yield results were observed in both weather conditions. Based on the examination of the obtained results, it was shown that the effect of weather conditions and the given number of plants have a smaller influence on the yield results of low-productivity zones, while these factors have a greater influence on the yields of high-productivity zones. [ABSTRACT FROM AUTHOR]

The development and commercialisation of sunflower varieties tolerant to acetolactate synthase (ALS)-inhibiting herbicides some 20 years ago provided farmers with an alternative method for the cost-effective control of Orobanche cumana. In 2020, however, two independent sunflower broomrape populations from Drama (GR-DRA) and Orestiada (GR-ORE), Greece, were reported to be heavily infested with O. cumana after application of the ALS-inhibiting herbicide imazamox. Here we have investigated the race of GR-DRA and GR-ORE and determined the basis of resistance to imazamox in the two Greek O. cumana samples. Using a set of five diagnostic sunflower varieties characterised by different resistant genes with respect to O. cumana infestation, we have clearly established that the GR-ORE and GR-DRA populations belong to the invasive broomrape races G and G+, respectively. Live underground tubercles and emerged shoots were identified at the recommended field rate of imazamox for GR-DRA and GR-ORE but not for two other standard sensitive populations in a whole plant dose response test using two different herbicide-tolerant sunflower hybrids as hosts. Sequencing of the ALS gene identified an alanine 205 to aspartate mutation in all GR-ORE samples. Most GR-DRA tubercles were characterised by a second serine 653 to asparagine ALS mutation whilst a few GR-DRA individuals contained the A205D mutation. Mutations at ALS codons 205 and 653 are known to impact on the binding and efficacy of imazamox and other imidazolinone herbicides. The knowledge generated here will be important for tracking and managing broomrape resistance to ALS-inhibiting herbicides in sunflower growing regions. [ABSTRACT FROM AUTHOR]

• Sunflower hybrids showed high tolerance to cadmium, with slight changes in growth. • Glutathione is probably involved in plant defence via synthesis of phytochelatins. • Cadmium accumulation depends on plant organ, genotype and metal dose. • Sunflowers are suitable for the phytostabilisation of cadmium-contaminated soils. • Better remediation potential of plants can be expected at lower cadmium doses. Common sunflower (Helianthus annuus L.) belongs to the group of crops with high biomass and high capacity for the accumulation of various metals. Previous studies have suggested that remedial potential is strongly determined by genotype. In our study, we evaluated the tolerance of six sunflower hybrids (P64HE118, P64LE136, P62LE122, P64HE133, P64HE144 and P63LP25) to cadmium ions (Cd 100 mg kg−1 soil), and we also evaluated their remediation potential. All tested hybrids showed high tolerance to Cd, no significant changes were noted with regard to growth, content of photosynthetic pigments, leaf area, water content, proline content, or accumulation of superoxide dismutase (SOD) isoforms. We noted an increased rate of membrane lipid peroxidation for P64HE118, P64LE136 and P64HE144 hybrids. The increased content of glutathione in the leaves of P64HE118 and P64LE136 hybrids indicates this molecule's involvement in the Cd detoxification process. All hybrids accumulated Cd preferentially in the roots. The most Cd was accumulated in the roots and shoots of hybrid P64HE118. Values of bioaccumulation factor and translocation factor were hybrid-dependent, being generally higher for standard/control soil (Cd 1.2 mg kg−1 soil). Better phytoremediation potential of these hybrids can hence be expected at lower Cd doses in the soil. The high tolerance of tested hybrids to a higher dose and the non-negligible accumulation of Cd in roots also supports using these hybrids in soil phytostabilisation. [ABSTRACT FROM AUTHOR]

The quantity and quality of sunflower oil are key factors for the crushing industry. This research presents a comprehensive analysis of the oil quality parameters of seven foreign sunflower hybrids grown in Morocco. Conducted over two consecutive years (2018 and 2019), the study focuses on key traits, including oil content, acidity index, peroxide index, refractive index, color index, total phenolic content, total flavonoid content, and antioxidant activity. Significant variations in most parameters, including color properties, were observed between the two years and among the seven varieties, indicating the influence of genetic and environmental factors. This highlights the importance of understanding the genetic potential of sunflower hybrids and the impact of environmental variables on oil quality. More favorable weather conditions in 2019, compared to 2018, contributed to better oil quality in all the varieties investigated. Overall, four homogeneous groups of hybrid varieties were identified based on oil content and other biochemical parameters. Some of these hybrids, like 'Niagara', had moderate oil content but high polyphenol content, flavonoid content and antioxidant activity, as well as a lower peroxide index, making them potential sources of natural antioxidant compounds as well as dietary supplements. Overall, this research provides sunflower breeders with valuable insights into the development of new high-performing hybrids with enhanced oil quality that could be used to produce functional foods with health benefits. These findings have implications for the use of seed oils from those hybrids in various industries and underscore the importance of further and more in-depth research on sunflower oil quality in the context of climate change. [ABSTRACT FROM AUTHOR]

The increasing demand from farmers for sunflower (Helianthus annuus L.) hybrids with high seed yield and high oil content requires the replacement of older hybrids with new hybrids that have improved traits and better adaptation to climate change. Multi-annual studies are essential for the evaluation of sunflower hybrids and the identification of those suitable with specific adaptations to various agroclimatic areas. Thus, to evaluate the adaptation of nine hybrids and test the impact of semi-arid conditions on seed yield, oil content, and some morphological traits, a 3-yr study was carried out in the conditions of Agricultural Research and Development Station (ARDS) Șimnic (Romania). The ANOVA results indicated the significant influence of the hybrid (H), year (Y) and the H×Y interaction on all the studied traits. Overall, the year 2020 was better for seed yield (2658.8 kg ha-1) and hectolitre weight (47.9 kg hL-1). On the other hand, 2021 was more efficient for oil content (46.8%), while 2022 was more efficient for plant height, head diameter and 1000-seed weight (133.5 cm, 19.8 cm, and 48.3 g, respectively). The highest seed yield was achieved by 'FD 18E41' with 1849.3 kg ha-1, this could reliably be used in sunflower farming under semi-arid conditions of South-Western Romania. For other traits, the superior sunflower hybrids were: 'FD19E42' for oil content (46.5%); 'Fundulea 911' for hectolitre weight (43.5 kg hL-1); 'Performer' for plant height (133.4 cm) and 1000-seed weight (55.3 g); 'Fundulea 708' for head diameter (18.8 cm). [ABSTRACT FROM AUTHOR]

This research aimed to address the issue of physical damage caused by long-term work in high-saline fields by electrifying sunflower growing machinery and designing control systems. Firstly, the method of establishing the equation of motion is used to obtain the parameters to carry out motorization modification, and then the control system is built using STM32 as the main controller, which has the functions of control, data acquisition, and alarm. The feasibility and stability of the study are verified by using a model vehicle to conduct tests of straight-line driving and steering in a simulated high-saline field. [ABSTRACT FROM AUTHOR]

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The research was conducted on the Bila Tserkva National Agrarian University experimental field on a typical deep, low-humus chernozem. The methods of main cultivation in the sunflower agrocenosis of grain-row crop rotation had a major influence on the soil structuring processes. The use of moldboard and no-moldboard tillage increased the number of the most agronomically beneficial aggregates (0.25-10 mm) in the 0-10 cm soil's layer at the beginning of the sunflower growing season by 6.0% compared to shallow no-moldboardof tillage the soil. By the end of the growing season in the sunflower agrocenosis in the 0-30 cm soil layer, compared to the beginning of the crop growing season, the number of agronomically beneficial aggregates (0.25-10 mm) decreased, the number of fractions larger than 10 mm and fractions smaller than 0.25 mm increased. The coefficient of structure for moldboard and no-moldboard tillage significantly increased compared to shallow no-moldboardof tillage. The use of shallow no-moldboardof tillage and moldboard with no-moldboardof tillage was led to an increase in the content of stable aggregates by 1.2-7.5%. The highest yield of sunflower was recorded for the use of moldboard with no-moldboardof tillage - 2.72 t/ha, which is significantly higher than other variants. The use of shallow no-moldboardof tillage for 10-12 cm with disc tools led to a notable decrease in productivity compared to the control. Improving the water resistance of soil aggregates during moldboard and no-moldboard tillage and shallow no-moldboardof tillage helps to preserve the soil's potential fertility. [ABSTRACT FROM AUTHOR]

This article examines the effects of integrated nutrient management on soil organic carbon status and sunflower yield in Alfisols. The study, conducted in India, found that the application of 100% NPK + Farmyard manure increased sunflower yield compared to the control. The use of chemical fertilizer with farmyard manure also improved yield sustainability and soil health. The article references several scientific articles that provide additional information on topics such as the effects of fertilizers and manure on crop yields and soil quality, soil testing methods, and estimating available nitrogen and soil organic matter. These resources are valuable for researchers studying soil science and agriculture in North India. [Extracted from the article]

Soil phosphorus (P) enrichment due to increased P fertilizer use in agriculture contributes to eutrophication and adverse environmental impacts. Thus, one of the biggest global concerns is to reduce enriched P from the soil. One appealing way to remove excessive of P in soil is through phytoextraction. Therefore, a study was conducted to evaluate cucumber (Cucumis sativus) and sunflower (Helianthus annus) for phytoextraction and the effectiveness of chemical amendments for soil P reduction. Crops were grown in a factorial design with five treatments, including control − 0P, applied recommended P for the crop, 0P + 6 g Ca/kg, 0P + 2.0 g Al/kg, and 0P + 0.6 g Fe/kg. Phosphorus accumulation was as high as 1.70% of dry weight for cucumber and 1.50% for sunflower. When cucumber and sunflower were grown in the control soil, the available P concentration was reduced by 11.04 and 7.50%, respectively. The available P was decreased after adding alum by 36.02 and 32.9% in soil used to grow cucumber and sunflowers, respectively with the yield reduction by 23.3 and 14.3%. Similarly, the yield reduction of two crops was 21.5 and 9.8% with application of FeCl3. The crop yields were not affected by the application of CaCO3. A greater reduction in resin P fraction in soils was observed in cucumber (93.12%) and sunflower (94.98%). The P can be removed from P-enriched soils by cucumber and sunflower crops at 2.20 and 1.13 g P/plant dry weight without affecting the yield. It can be concluded that even though both crops are worthy nominees for phytoextraction, the cucumber shows superior ability over the sunflower. [ABSTRACT FROM AUTHOR]

The presented results of the study on the effect of biopreparations and different fertilizer systems on the formation of sunflower yield and productivity, determination of economic efficiency of sunflower cultivation under sharp fluctuations in climatic conditions through the use of biotechnology elements and fertilization. Growing sunflower without seed treatment with biopreparations under mineral fertilizer system provided an average yield of 2.93 t/ha, with an additional 0.31 t/ha of sunflower seeds. The organo-mineral fertilizer system resulted in the highest increase in additional production – 0.50 t/ha, and the increase in sunflower yield through fertilization system was the most significant, with a minimum important difference (MID05) of 0.11 t/ha. Seed treatment with biopreparation contributed to an increase in sunflower yield in all fertilizer systems: without fertilizer application, only due to the action of biopreparation, the yield increased to 2.82 t/ha; application of mineral fertilizer ensured a harvest of 3.09 t/ha of sunflower seeds; the organo-mineral fertilizer system had the highest yield indicator – 3.23 t/ha. The highest output of dry matter from the production was obtained through seed treatment with biopreparation and the use of organo-mineral fertilizer system, which provided a yield per hectare of: grain units – 6.47 t, fodder units – 3.56 t, digestible protein – 1.23 t. However, the most significant increase in sunflower productivity was observed in the organo-mineral fertilizer system without seed treatment with biopreparation. The highest indicators of economic efficiency of sunflower cultivation were observed under the conditions of seed treatment with biopreparation without fertilizer application, which amounted to 18,322 UAH/ha – net profit at a profitability of 91.5 %. [ABSTRACT FROM AUTHOR]

Water demand has intensified the modernization of irrigation techniques, contributing to the optimization and/or development of technologies that aim to improve plant performance, such as nutrient uptake. Thus, the objective of the present study was to evaluate the macro- and micronutrient levels in leaves of ornamental sunflowers grown with different irrigation depths with magnetized water or ordinary water. The experiment was conducted in a greenhouse following a 5x2 factorial scheme in a randomized block design. The treatments consisted of a combination of 5 irrigation depths based on crop evapotranspiration (ETc) (0.2, 0.7, 1.0, 1.3, and 1.6 ETc, corresponding to the irrigation depths of 56.47, 104.89, 133.94, 162.99, and 192.04 mm, respectively) and 2 types of irrigation water (magnetized water or ordinary water). The deepest irrigation depths generated the highest leaf concentrations of nitrogen (N), phosphorus (P), calcium (Ca), and zinc (Zn) and the lowest potassium (K), copper (Cu), and iron (Fe) concentrations. The leaf concentrations of magnesium (Mg), sulfur (S), boron (B), and manganese (Mn) were not significantly influenced by the irrigation depth. Ordinary water favored higher leaf concentrations of S, Cu, and Mn, while there were no significant differences between the water types regarding the levels of the other nutrients. [ABSTRACT FROM AUTHOR]

Bumble bees are globally important pollinators, contributing hundreds of millions of dollars annually in crop pollination services. Several species are in decline, making it paramount to understand how pathogens and nutrition shape bee health. Previous work has shown that consuming sunflower pollen (Helianthus annuus) dramatically reduces infection by the trypanosomatid gut pathogen, Crithidia bombi , in the common eastern bumble bee (Bombus impatiens). Sunflower pollen may therefore be useful as a dietary supplement for reducing this pathogen in managed bumble bee colonies. Here, we assessed the efficacy of freezer-stored sunflower pollen that was collected in different years and locations for reducing pathogen infection. We tested sunflower pollen that was 1, 3, 4, or 5 yr old and from sunflowers grown in the United States or China against a control of 1-yr-old buckwheat pollen from China, since buckwheat pollen results in high infection. We hypothesized that older pollen would have weaker medicinal effects due to degradation of pollen quality. We found that all sunflower pollen treatments significantly decreased Crithidia infection compared to controls. These results suggest that sunflower pollen can be freezer-stored for up to 5 yr and sourced from a wide range of geographic areas and still maintain its medicinal effects against Crithidia in the common eastern bumble bee. This is helpful information for stakeholders who might administer sunflower pollen as a dietary supplement to manage Crithidia in commercial bumble bee colonies. [ABSTRACT FROM AUTHOR]

Sunflower, third most important oil seed crop having high potential to grow in the coastal salt-affected seasonal fallow lands of the Ganges river delta, its nitrogen fertilizer requirement, and use efficiency yet not defined for the region. The main objective of the experiment was to determine optimum rate of nitrogen (N), which maximizes yield and N use efficiency. The field experiment was carried out in dry-season of two consecutive years (2020 and 2021). The randomized complete block design model was employed to prepare the layout of the experiment where all the treatments were replicated thrice. Eight rates of N comprising 0, 21, 42, 63, 84, 105, 126 and 147 kilogram N per hectare (kg N ha−1) were the treatments in the experiment. Statistically higher grain yield (3.49 ton per hectare; t ha−1), straw yield (7.47 t ha−1), number of seeds head−1 (1195), 1000-seed weight (74.4 gram; g) and total N uptake (197 kg ha−1) was found in 126 kg N ha−1 rate. This rate had partial factor productivity of 26 kg grain kg−1 added N, agronomic use efficiency of 14.2 kg grain kg−1 added N, physiological use efficiency of 13.9 kg grain kg−1 N uptake and recovery efficiency of 1.04 kg N uptake kg−1 added N. The 126 kg N ha−1 was therefore recommended to grow sunflower in the seasonal fallow coastal salt-affected lands of the Ganges river delta. [ABSTRACT FROM AUTHOR]

Boron (B) uptake by plants is not always related to the availability of B in the soil. Since B is not mobile in the phloem, conditions such as drought, irregular irrigation, high relative humidity and salinity adversely affect plant B uptake and transport. Thus, new strategies should be developed to improve the transport of B in plants. In this study, greenhouse experiment was conducted to examine the effects of calcium borate nanoparticles (Nano-B) on the B and Ca concentrations of sunflower plants. Nano-B have been synthesized by a method via co-precipitation and characterized by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The effects of Nano-B, disodium octaborate tetrahydrate (DOT) and colemanite on growth and B uptake of sunflower plant grown in B-deficient acidic and alkaline soils were investigated in greenhouse conditions. Boron was applied at 5 mg kg−1 level. Total B and calcium concentrations were determined separately in young leaf, old leaf and stem. According to the results, there is no difference between B sources and control in terms of fresh and dry weight of the plants. However, all B sources increased the young and old leaf B concentrations of the plant compared to the control. Nano-B treatment was prominent in terms of B concentrations on the old leaves in alkaline soil and on stem in acidic soil. It has been concluded that Nano-B can be an alternative B source and it is necessary to test it in different plants under different growing conditions. [ABSTRACT FROM AUTHOR]

Biochar is preferentially recommended for the remediation of heavy metal-polluted soils. Sunflower is an important high-biomass oil crop with a promising potential for phytoremediation of Cr(VI)-polluted soil. However, how biochar affects sunflower growth and Cr accumulation in Cr(VI)-polluted soil needs to be elucidated. Here, a pot culture experiment was conducted to study whether soil amendment with biochar (0, 0.1%, 1%, and 5%, w/w) can mitigate Cr toxicity and accumulation in sunflower seedlings grown in soils artificially polluted with different levels of Cr(VI) (0, 50, and 250 mg Cr(VI)/kg soil). The addition of Cr(VI) exhibited significant phytotoxicity, as evidenced by inhibited plant growth and even the death of seedlings at 250 mg/kg Cr(VI). Overall, biochar amendment showed positive effects on plant growth and Cr immobilization, dependent on both the biochar dose and Cr addition level. When 50 mg/kg Cr(VI) was added, 1% biochar showed positive effects similar to 5% biochar on improving plant growth and mineral nutrition (particularly K), reducing Cr content in shoots and roots, and decreasing Cr availability and Cr(VI) content in the soil. In comparison with non-amendment, 1% and 5% biochar caused 85% and 100% increase in shoot dry weights, and 75% and 86% reduction in shoot Cr concentrations, respectively. When 250 mg/kg Cr(VI) was added, a 5% dose produced much better benefits than 1%, while a 0.1% dose did not help plants to survive. Overall, an appropriate dose of biochar enhanced Cr(VI) immobilization and subsequently decreased its toxicity and accumulation in sunflower seedlings. Our findings confirm that biochar can be used as an efficient amendment for the remediation of Cr(VI)-polluted soils and cleaner production of sunflower oil and biomass. [ABSTRACT FROM AUTHOR]

The growing media is one of the significant elements affecting microgreens' yield and quality. This experiment investigated the possibility of waste utilization instead of employing peat moss to produce sunflower and water-spinach microgreens. The treatments consisted of peat moss (Control), coconut coir dust (CD), leaf compost (LC), food waste compost (FC), CD:LC = 1:1 v/v, CD:FC = 1:1 v/v, LC:FC = 1:1 v/v, and CD:LC:FC = 1:1:1 v/v. The results proved that the highest yield of sunflower microgreens was observed when cultivated in 1:1 v/v of CD:LC media (10,114.81 g m−2), whereas the highest yield of water spinach microgreens was recorded under the treatments of CD, Control, 1:1 v/v of CD:LC, and 1:1:1 v/v of CD:LC:FC media (10,966.67–9800.00 g m−2). The biochemical composition of the microgreens varied within the types. Our findings demonstrated that a tendency of an increase in chlorophyll and carotenoid contents depended on the growth of both microgreens under different growing media. All growing media did not cause excess nitrate residue or pathogenic contamination in both microgreens, namely Clostridium perfringens, Salmonella spp., and Staphylococcus aureus. In contrast, almost all the growing media resulted in a higher population of Bacillus cereus contamination in both microgreens than the standard set limit, except for sunflower microgreens grown in the control and CD growing media. These findings could suggest that the 1:1 v/v of CD:LC and CD media were the most effective growing media for sunflower and water spinach microgreens, respectively, but further cleaning before consumption is recommended to avoid or reduce the foodborne incidences caused by B. cereus in microgreens. [ABSTRACT FROM AUTHOR]

Climatic changes in recent years have adversely affected the development of a number of crops. Especially the spring ones suffer, since the development phases in which the yield is formed take place during the periods most strongly influenced by climate change. In the present study, the different climate components during the period 1991-2020 that most strongly influence sunflower development are characterized. It was established that the unfavorable trends of changes in agrometeorological conditions in the studied area are related to a decrease in summer precipitation and an increase in temperatures during the same period. As a result, the last two months of the sunflower growing season are in a moisture deficit. Temperatures in the region during the studied period have increased, with positive deviations in all months, except for December. No differences were recorded in the dates of the transition of the air temperature through 5o C. During the researched period, they increased by 167o C compared to the previous one. During the studied period, precipitation in summer decreased at the expense of its increase in autumn, compared to the previous one. [ABSTRACT FROM AUTHOR]

Sunflower is a major field oilseed crop in Bulgaria. Uncontrolled weed flora is the main competitor during sunflowers' vegetation. The present study aims to determine the weed infestation in different growth stages of sunflowers and to determine their influence on the productivity of the crop. The study was conducted during two sunflower growing seasons with the sunflower hybrid „Coloris“ CL in 2022 and 2023. The experiment was carried out on the agricultural land of Novoseltsi village, in the region of Vidin city, Bulgaria. The weed mapping was determined by the П-method for weed survey in spring field crops. A comparison of the weed infestation was determined between untreated plot and plot with an application of the tank mixture of the herbicidal products Pulsar Plus (25 g/l imazamox) – 1.60 l ha-1 + Stratos Ultra (100 g/l cycloxydim) – 2.00 l ha-1. The herbicides were applied in the 4th-6th true leaf stage of sunflower. In the two experimental years, the sunflower was grown after preceding crop winter wheat. During the two years of the study, and during the two survey periods (1st – in growth stage 8th - 10th true leafs stage of sunflower, and IInd - during the flowering of the crop) the predominant weed species were ragweed (Ambrosia artemisifolia L.) and wild hemp (Cannabis ruderalis Janisch.), followed by the weed Rough cocklebur (Xanthium strumarium L.). During the trial, no visual signs of phytotoxicity were detected in sunflower after the application of Pulsar Plus + Stratos Ultra in tank mixture. Sunflower seed moisture content was higher for the plants from the untreated plot. Statistically higher results for the studied indicators, such as seed yield, absolute and hectoliter seed mass were established after the application of Pulsar Plus + Stratos Ultra. [ABSTRACT FROM AUTHOR]

In modern agricultural systems, the basis of cultivation technology and an important factor determining the yield and quality of high-oleic sunflower seeds is regulation of mineral fertilizer rates. Therefore, the determination of their influence on the productivity of the culture determines the relevance of the conducted research. The purpose of the study is to determine the optimal rates of mineral fertilizer application to increase the yield of high-oleic sunflower hybrids in non-irrigated conditions of the Southern Steppe of Ukraine. To achieve the goal, a field study was conducted in the fields of the Mykolaiv State Agricultural Research Station of the Institute of Irrigated Agriculture of the National Academy of Agrarian Sciences of Ukraine. The subjects of the study are high-oleic sunflower hybrids Kadet, Hektor and Oplot, the originator of which is the V.Ya. Institute of Plant Breeding. Yuryev of the National Academy of Agrarian Sciences of Ukraine. As a result of the study, it was found that when applying N90P90K60, the Kadet hybrid formed the largest diameter of the basket - 19.5 cm, under the same feeding conditions, the diameter of the basket in the Hektor and Oplot hybrids was 14.3 cm and 16.4 cm, respectively. The largest mass of 1000 seeds for the level of N90P90K60 fertilization was established in the hybrid Cadet - 59.8 g, and at the level of fertilization N30P40K30 the lowest mass of 1000 seeds - 41.7 g was formed in the hybrid Hector. In addition, in the high-oleic sunflower hybrid Kadet, the content of crude fat in seeds and oleic acid in oil was the highest compared to other hybrids in all variants of fertilization. The application of mineral fertilizers also affected the yield of high-oleic sunflower, so the yield of the Kadet hybrid was 24.1% higher with the application of N90P90K60, compared to the variant of application of N30P40K30, and the yield of the Hektor and Oplot hybrids was 33.3% and 28%, respectively, which makes it possible to state that the level provision of mineral fertilizers helps to increase crop productivity. The obtained results provide an opportunity to improve the technology of growing high-oleic sunflower under conditions of insufficient moisture, and the perspective of further research may be to study the effect of increased norms of each individual macroelement or their joint effect on the productivity and quality of the high-oleic sunflower crop [ABSTRACT FROM AUTHOR]

Sunflower represents the main oil crop in Romania and is considered a moderately crop drought tolerant but in years with low precipitations seed yield is affected. In recent years, the temperature increased by 2-3 degrees Celsius compared to multi-year average over 60 years. In south-eastern of Romania (agricultural area Fundulea), in 2020, the average annual temperature was 13.5°C, in 2021, it was 12.1°C and in 2022, it was 13.3°C compared with multi-year average over 60 years who was 10.9°C. Rainfalls decreased in last four years from value of 303.3 mm, multi-year average over 60 years total from months April to August in South eastern of Romania, to a total of 180 mm in years 2020 and 2022, 269 mm in year 2021 and a total of 200 mm in 2023. In conditions of water stress and global warming we must identify sunflower genotypes with tolerance at drought and heat. In this paper we present results regarding resistance at water stress through observations development root system of sunflower genotypes under artificial condition in greenhouse and behavior in non-irrigated field in Calarasi county (Fundulea area) and Braila, in year 2023. Sunflower genotypes, S 23-5, S 23-6 and S 23-7 with very developed root system in water stress conditions was obtained thought interspecific hybridization with wild annual specie Helianthus argophyllus and with wild perennial species Helianthus tuberosus and Helianthus maximiliani. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.) growth and yield are severely compromised by boron (B) deficiency in alkaline calcareous soils of Pakistan. Biochar produced through low-temperature pyrolysis helps to maintain acidic functional groups in such soils. The aim of this study was to enhance B availability in biochar-amended alkaline calcareous soils in order to improve morpho-physiological and yield attributes of sunflower. In a pot experiment, sunflower was grown with three fertiliser treatments: diammonium phosphate (DAP) alone; simple B + DAP; and DAP coated with biochar and B (BC-BDAP). All treatments were grown in soil receiving no biochar, and the BC-BDAP treatment was also applied in soil amended with wheat straw biochar at 2% and 4%. Preparation with wheat straw biochar improved soil properties such that soil with 4% biochar showed highest levels of organic matter (0.97%), total nitrogen (0.08%), available phosphorus (6.21 mg/kg), extractable potassium (93.4 mg/kg) and available B (0.41 mg/kg). Furthermore, compared with DAP alone and B + DAP, BC-BDAP in 4% biochar-amended soil enhanced the concentrations of shoot B (by 64% and 35%) and root B (by 41% and 26%), respectively. This indicated sufficient B availability in soil for root absorption, which subsequently increased sunflower achene weight per plant (by 33% and 17%), protein content (by 29% and 18%) and oil content (by 17% and 10%). Thus, application of BC-BDAP fertiliser in 4% biochar-amended soil can be an efficient strategy for enhancing B availability in alkaline calcareous soils and increasing sunflower growth and yield. Boron is an essential micronutrient that stimulates plant metabolic and developmental processes. This study aimed to enhance boron availability through the development of biochar- and boron-coated diammonium phosphate (BC-BDAP) for use in biochar-amended alkaline calcareous soils. Data showed improved nutrient (boron and phosphorus) uptake with application of BC-BDAP in 2% and particularly 4% biochar-amended soil, which further improved the growth, yield and oil content of sunflower relative to DAP alone or boron + DAP without biochar amendment. [ABSTRACT FROM AUTHOR]

As climate changes, the development of new agroecological systems and the diversification of crop rotations open new opportunities for growing sunflowers in the northern regions of Europe. However, there is a lack of knowledge about the effect of sunflower grown in the Boreal region on other plants in crop rotation. This experiment was aimed to evaluate the allelopathic effect of aqueous extracts of different parts of the common sunflower (Helianthus annuus L.) grown in the Boreal environmental zone on seed germination and growth of the field pea (Pisum sativum L.). The following three factors were studied: factor A - two fertilisation levels of sunflower: unfertilised (N0P0K0) and fertilised by N80P60K90; factor B - three sunflower plants parts: leaves and stems (L+S), heads (H), and roots (R) for extract preparation; factor C - four concentrations (25%, 50%, and 75%) of sunflower aqueous extracts and deionised water (0%) as a control. All concentrations of sunflower extracts stimulated seed germination by 1.7-6.7% at 4 days after sowing (4 DAS), compared to the control treatment. Extracts of heads and roots of sunflower had a significant (p = 0.05) inhibitory effect on pea root length and shoot length (7 DAS and 18 DAS, respectively). The roots extract contained the highest total polyphenolic content and total flavonoid content and had the greatest inhibitory effect on the fresh mass of roots and shoots. The data averaged across fertilisation level showed that 25% concentration of all sunflower parts extracts had a stimulatory effect, and extracts of 75% concentration had the highest inhibitory effect on root morphological parameters of pea. The results revealed that sunflower can be an allelopathic species causing a risk in a crop rotation. The suppressive effect of sunflowers on other plants including weeds can be applied in sustainable agriculture. Therefore, the detailed studies are necessary for further reveal of the allelopathic effect of sunflower grown in the Boreal environmental zone not only on peas but also on other target crops. [ABSTRACT FROM AUTHOR]

Given the beneficial effects of cover crops, their planting is a good way to improve soil fertility, reduce soil erosion, effectively control weeds, etc. some ecological variables were selected for sunflower and berseem clover land suitability assessment, and thematic maps were developed for each of the parameters in Geographic Information System (GIS). Finally, highly suitable, suitable, moderately suitable and unsuitable areas were detected by analytic hierarchy process (AHP). The findings indicated that the ordinary kriging interpolation model was the best model to evaluate the agricultural land suitability assessment for sunflower and berseem clover production in the region. Also, the climatic variables had a major role in the development of sunflower and berseem cultivation, and soil and topography variables ranked next. The final land suitability map revealed that the most highly suitable areas (3358.4 ha) were located in the north of the region, and the rest was suitable (15257 ha) areas for growing sunflower. Also, northwest and very limited areas from the northeast and southeast of the region showed highly suitable conditions (3534.4 ha), and other areas had suitable (15081 ha) condition in cultivation of berseem clover. Therefore, almost areas were suitable for it. [ABSTRACT FROM AUTHOR]

Plant-arbuscular mycorrhizal (AM) fungi association is one of the oldest symbiotic relationships between organisms. This relationship may be more important under stress conditions such as drought and can help the host plant tolerate drought. This study was conducted in 2016 and 2017 at the Agricultural Research Farm of Razi University, Kermanshah, Iran to evaluate the effect of AM fungi (AMF) inoculation (with either Funneliformis mosseae or Rhizophagus intraradices) on some physio-biochemical traits of three sunflower cultivars under different soil irrigation treatments (severe water deficit stress, mild water deficit stress and wellwatered). In both years, water deficit conditions significantly reduced leaf relative water content (RWC), chlorophyll concentrations (a, b and total) and shoot phosphorus concentration (SPC) while simultaneously increasing shoot proline levels and malondialdehyde (MDA) concentrations. AMF inoculation had positive effects on RWC, chlorophyll concentrations and SPC irrespective of sunflower cultivar and irrigation treatment. Shoot proline concentration and MDA reduced more in AM than non-AM plants. In most cases F. mosseae performed better than R. intraradices in terms of plant performance. Moreover, the improvements caused by AM fungi were more evident under water deficit than well-watered condition. It may be concluded that AM inoculation can alleviate the negative effects of water deficit stress on some important physiobiochemical traits of sunflower grown in the field, and can be considered as a practical and economical approach to improve crop performance in environments exposed to water limitations. [ABSTRACT FROM AUTHOR]

Genotype-environment interaction is an important factor limiting yield in sunflower as in other plants. Stability of the genotypes was investigated by using AMMI analysis in terms of seed yield obtained from oil sunflower genotypes grown under multi-environmental conditions. This work; The study was carried out with a total of twelve oil sunflower genotypes in six locations for two years (2016 and 2017) in a randomized block design with four replications. The most stable genotypes and genotypes compatible with special environments were tried to be determined by AMMI analysis. With AMMI analysis, it was determined that the mean of squares was affected by the environment with 73.5%, interaction with 19.5% and genotype with 7.0%. According to the results of the analysis, the G3, G8 genotypes are quite stable and together with these varieties, the G4, G6, G7, G9 and G10 genotypes have a seed yield above the average, the G1 genotype has a very low seed yield, and the G9, G10 and G11 are located quite far from the stability line. therefore, they were found to be unstable. When the environments were evaluated with AMMI analysis, it was determined that E5 was the most suitable and highly productive, and together with this environment, E10 and E11 resulted in a seed yield above the average yield. In addition, in the sector analysis made, it is seen that G4 and G6 are high in E3, E4, E7, E10 and E11 circles, G8, G7 and G1 are high in E1, E2, E5, E6 E8 and E12 circles, and G2 and G9 are only high in E9 circles. performance and were specifically recommended for these environments, while other remaining genotypes such as G1 and G5 were not associated with environments. As a result, visually the most stable and high yielding genotypes were determined by AMMI analysis. [ABSTRACT FROM AUTHOR]

The article provides a comparative analysis of sunflower seed production in Ukraine, the EU and globally for the period from 2000 to 2021. The Ukraine's share in the world sunflower production was found and analyzed. The analysis of the gross collection of sunflower seeds in the regions of Ukraine for two conditional periods (2000–2010 and 2011–2021) was carried out. Thus, during the researched period, the average yield increased from 1.04 t/ha in 2000 to 2.57 in 2021, i.e. by 2.5 times. It became possible due to the improvement and adaptation of cultivation technology and careful selection of sunflower hybrids that are better adapted to climatic changes. It was determined that the change in climatic conditions has affected the zones of comfortable sunflower cultivation in Ukraine. According to the yield index, during the first conditional period the central regions of Ukraine were in the lead (1.57 t/ha), and during the second period, the northwest regions of the country stepped up (2.83 t/ha). The above data suggest that the gradual change in sunflower cultivation technology and the search for new drought-resistant crop hybrids give hope that Ukraine will maintain its position in the world as a leader in the export of sunflower oil. [ABSTRACT FROM AUTHOR]

[Display omitted] • We design the novel bio-based MXene-reinforced polythioether nanocomposites. • MPS-MXene can enhance the glass transition temperature, tensile strength, and Young's modulus of the polythioether/MXene nanocomposites. • The composite has high photothermal conversion efficiency and excellent shape memory performance with R r (>98 %). • All the polythioether/MXene nanocomposites showed self-extinguishing performance. Thermosetting shape memory polymers (TS-SMPs) have a higher shape fixity ratio (R f) and shape recovery (R r) due to their structure integrity and thermal stability, and the glass transition temperature (T g) usually influences the transition temperature (T trans) of TS-SMPs. Therefore, it is significant to tailor the T g range and mechanical properties for TS-SMPs. In this work, the inherently flame-retarding bio-based MXene-reinforced polythioether nanocomposites with excellent shape memory performance, driven by photothermal response, were designed. Firstly, a photopolymerizable MXene nanomonomer (MPS-MXene) was obtained by introducing 3-(methacryloxy) propyltrimethoxysilane onto the surface of the MXene monolayer. Then, the bis(4-allyl-2-methoxyphenyl) phenyl phosphonate (BEP) was synthesized by eugenol (a lignin derivative) with phenyl phosphonic dichloride. The polythioether/MXene composites (BEP-T- x M) were synthesized through in-situ thiol-ene photopolymerization of MPS-MXene, BEP, and tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate. Surprisingly, compared with neat polythioether, the T g of BEP-T-0.2 M composite increased from 19.6 to 34.6 °C, when only 0.2 wt% MPS-MXene was added. The photothermal conversion efficiency (η = 73.8 %) and shape memory performance with R r (>98 %) were greatly improved. Consequently, the interesting phenomena such as "sunflowers growing towards the sunlight" and "thermal shrinkage" can be observed. Meanwhile, the tensile strength and Young's modulus increased significantly by 141 % and 91 %, respectively, due to the good dispersion of rigid MPS-MXene nanosheets. Furthermore, all the polythioether/MXene composites showed self-extinguishing performance. This study will provide a novel strategy for designing biobased photothermal-responsive TS-SMPs. [ABSTRACT FROM AUTHOR]

Soil heavy metal contamination is often an unintended byproduct of historic land-use. This contamination can negatively impact resident plants and their interactions with other organisms. Plant fitness in contaminated landscapes depends not only on plant growth, but also on the maintenance of interactions with pollinators. Cadmium (Cd) is a heavy metal that is commonly found in agricultural, urban, and industrial ecosystems as a legacy of historic land-use. It is a prioritized pollutant in soils because of its wide distribution and strong biotoxicity. To understand how Cd influences plant growth and pollinator interactions, we grew sunflowers in media with three different Cd concentrations to represent the range of Cd contamination faced by sunflowers growing on land recovering from past land-use. We measured Cd contamination effects on sunflower morphology and pollinator foraging behavior, specifically the number of visits and visit duration. We then measured seed number and weight to determine if contamination directly or indirectly, as mediated by pollinators, altered plant fitness. Plant height was negatively correlated with Cd concentration, but contamination alone (in the absence of pollinators) did not affect sunflower reproduction. Bumble bees visited sunflowers grown in Exceeding Threshold Cd concentrations less often and for shorter time compared to visits to Below Threshold Cd sunflowers, but honey bees and sweat bees showed similar foraging behavior across Cd contamination treatment levels. Sunflower seed set was positively correlated with the total number of pollinator visits, and sunflowers grown in Exceeding Threshold Cd soil had marginally lower seed set compared to those grown in Below Threshold Cd soil. Our results suggest that at Exceeding Threshold Cd contamination levels plant-pollinator interactions are negatively affected with consequences for plant fitness. [Display omitted] • We grew sunflowers in media contaminated with Cd at three contamination levels. • Sunflower height decreased with increasing Cd concentration. • Sunflower seed weight, a measure of fitness, increased with pollinator visits. • Bumble bees visited flowers grown in high Cd media less often and for less time. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthusannuus L.) is one of the most important oil crops in the world and mostly produces oil. Due to the global warming and unexpected climatic changes especially extreme heat and droughts in recent years, as a spring crop sunflower affects severely by these climatic conditions in the vegetation period and loses seed yield hardly. Plant breeding longer process taking at least ten years to develop cultivars. Therefore, sunflower breeders should consider future climatic conditions, hence it seems that drought tolerance should consider primarily in their breeding programs. Oil content is the most important trait in sunflower than the major goal in the breeding studies; likewise, it is the most affected yield trait in sunflower from drought conditions. The study was conducted to determine the oil contents from drought some inbred lines and their hybrids developed lately in National Sunflower Project conducting by Trakya Agriculture Research Institute (TARI). Based on the study results; the significant relationships were observed between oil content and other yield traits in drought conditions. Oil content of male lines exhibited more variability than female lines changed as 13.16%–54.05% male lines and 19.12%–52.46% in female lines, and 30.17%–53.68% in the hybrids. While oil content of inbred lines affected negatively mostly from thousand seed weight and head diameter, leaf number, leaf area, and seed yield followed this trait, respectively. Based on path analysis for the contribution of yield traits on determining of oil content; it determined that seed and oil yield were the most directly affected traits then followed by oil yield in sunflower inbred lines in a negative way, and other yield traits mostly affected oil content determination in drought stress conditions over these two traits. The seed and oil yield, leaf area, and thousand seed weight reduced about over 90% in the drought in inbred lines. Severe droughts resulted heavy decreases in sunflower oil content as well as in the seed and oil yield and other yield traits so no need to focus on increasing oil contents over 40%–43% and it should be sacrified from this trait in that kind of conditions. The sunflower hybrid evaluations in three different locations mentioned that thousand seed weight, seed yield, and leaf area as well as leaf number are the most important yield traits affecting positively of oil content determination in drought stress conditions. Practical applications: Sunflower is commonly influenced by the environmental conditions, such as hot temperatures and drought as being a spring growing crop. These environmental stresses mostly appear during mid‐summer then sunflower suffers from these stressess resulting of seed and oil yield losses with lower oil content. Especially the stress in the grain filling period results in lower oil content in the sunflower growing season. The study results mentioned that sunflower breeders should consider more male inbred lines to develop better oil content hybrids for drought stress. Furthermore, thousand seed weight is also the most important seed characteristics other than seed and oil yield for consisting of oil content in sunflower. Therefore, we have to focus on developing higher seed yield instead of higher oil content because sunflower sacrifice from seed yield to give higher oil content over 40%–43% during the stress conditions. [ABSTRACT FROM AUTHOR]

This paper aims to provide analysis of the main features of regional production of sunflower seeds in Ukraine. To realize aims in the article, the importance of agriculture was pointed and evaluation of sunflower seeds productions in accordance with natural and climatic zones were done. Results showed that areas under sunflower have increased significant and in 2021 there was observed the share of 52% of the harvest collected by agricultural enterprises in the Steppe zone, 39% in the Forest-steppe zone, and 9% in the Polissya zone. Grouping enterprises under the area size of sunflower growing confirmed the fact that the bigger arable land of sunflower has the enterprise, the more productive will be sunflower production, in particular, enterprises that have arable land under sunflower more than 2000 ha get yield more than 24 centners per hectare. These enterprises have possibilities to use new technologies to achieve the desired effect during production. The area and introduced pesticides factors was taken into account in regression analysis due to the importance of both them in increasing sunflower seeds production. Results showed close dependence between mentioned factors. In the article discussed a few aspects regarding the sunflower seeds market in Ukraine under the condition of the hostilities in the region. There are evaluated experts opinions regarding production capacities, processing, export and prices on the domestic and world market. [ABSTRACT FROM AUTHOR]

Synergistic effect of biochar and microbes in soil enhances performance of plants. Hazardous tannery solid waste can be reduced by one-third in volume by conversion to biochar. A greenhouse trial was set up with soil having different doses of metal resistant microbe-impregnated biochar (MIBC) prepared from tannery solid waste. Consortia of autochthonous strains of Trichoderma and Bacillus were inoculated on BC and the behavior and fate of metals were evaluated for their bioavailability to sunflower. Sunflower was grown in pots for 80 days having six different amendments of tannery solid waste biochar (0–10% w/w) with and without Trichoderma and Bacillus consortia and its morphological and biochemical attributes as well as metal uptake were observed. The results illustrated that application of BC at 2% rate without inoculation increased the shoot length and dry biomass by 19.8% and 77.4%, respectively, while plant growth and performance were reduced at higher amendments of BC. However, application of MIBC with Trichoderma or/and Bacillus consortium significantly improved the plant attributes at all levels of amendment. The results indicated that MIBC having Trichoderma and Bacillus consortia at 10% rate increased shoot length and dry biomass by 65.3% and 516% compared to control without BC. Application of BC without inoculation reduced the uptake of Cu, Fe, and Ni and increased the mobilization of all other metals for uptake in sunflower. Mobilization and uptake of Cd, Cr, Cu, Ni, Pb, and Zn decreased with MIBC having Trichoderma and Bacillus consortia whereas that of Fe and Mg were noted. A considerable decrease in proline and total phenolic content was demonstrated by MIBC-grown sunflower. The data of metal fractionation in BC also supported the above findings. Therefore, MIBC can be used as a promising option for enhancing growth performance and ensuring the physiological safety of sunflower as an energy crop. [ABSTRACT FROM AUTHOR]

• Interactive effects of different temperatures (15 °C and 40 °C) different boric acid concentrations (10 and 25 mM) were investigated in this study. • Phenological parameters, MDA level, SOD, CAT, APX activities and gene expressions were determined. • Boric acid application increased the negative effect of high temperature stress on all parameters examined. • It has been determined that boron supplementation in the plant is an important factor in tolerating low temperature stress. Plants have to cope with more than one abiotic stress at the same time in nature. Heat stress and mineral toxicity are at the forefront of these abiotic stresses. The purpose of this study is to investigate the interactive effects of high and low-temperature stress and boric acid application on the sunflower and reveal the potential protection mechanisms against the combined effect of two types of stress. Two different boric acid concentrations (10 and 25 mM) were applied to sunflowers grown separately at low (15 °C), optimum (25 °C) and high (40 °C) temperature. Then, root length and stem height, root and stem fresh-dry weight, root and stem biomass, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) enzyme activities and changes in the gene expression levels of these enzymes were determined. It was determined that there were reductions in the phenological properties of the roots and stems of the samples grown at 40 °C based on the increasing boric acid concentration, while the samples grown at 15 °C were positively affected. The antioxidant enzyme activities and mRNA levels of the root and leaf samples at 40 °C were observed to increase. For the samples at 15 °C, the antioxidant enzyme activities and mRNA levels increased in the roots and decreased in the leaves. Considering phenological parameters, it was revealed that high boric acid application at low temperatures promoted plant growth, and considering the antioxidant enzyme activities and mRNA expression levels, it was highly effective in the plant's toleration of low temperatures. [ABSTRACT FROM AUTHOR]

Background: Remediation of heavy metals contaminated soils is a crucial issue. This study was conducted to evaluate the effect of nano Fe-oxide and multiwall carbon nanotubes(MWCNs) on diesel oil bio-degradation in the soil polluted with Pb and Cd and enriched with vermicompost under ornamental sunflower cultivation. Methods: Treatments were soil application of MWCNs at the rates of 0, 1, and 2 % (W/W); 0, 15, and 30 t/ha vermicompost; 0 and 0.5 % (W/W) nano Fe-oxide in soils polluted with Pb and Cd as well as 0, 4, and 8 % (W/W) diesel oil. After harvesting, the Pb and Cd concentrations of plant and soil were determined using AAS. Furthermore, the diesel oil bio-degradation in the soil was measured. Results: Using 1 and 2 % (W/W) MWCNs significantly increased the diesel oil biodegradation by 15.3 and 17.4%, while the Pb concentration in soil decreased by 13.1 and 15.8%. In addition, the Cd concentration, decreased by 14.2 and 16.1%, respectively. The Pb and Cd concentrations in plant showed the similar trends. Using vermicompost significantly increased the diesel oil bio-degradation. Conclusion: Using nano-Fe oxide and MWCNs significantly increased the biodegradation of diesel oil in soils polluted with Pb and Cd. [ABSTRACT FROM AUTHOR]

Over the past 15-20 years, Ukrainian agricultural production has shifted to growing more profitable, highly marketable, and drought-resistant crops, in particular, chickpeas and sunflower. Therewith, the technology of growing these crops is energy-consuming, especially in irrigation conditions. Therefore, it is relevant to examine the influence of microirrigation system designs on the energy parameters of chickpea and sunflower cultivation. The purpose of the study is to perform an energy assessment of chickpea and sunflower cultivation depending on the design of microirrigation systems and the method of water supply. Research methods: short-term field experiments, analytical and statistical methods for processing experimental data. The scheme of experiments provided for laying irrigation pipelines in the horizontal and vertical planes, and implementing a pulse water supply mode (standard). Control is an option without irrigation. It is established that the method of laying pipelines (designs of microirrigation systems) substantially affects the productivity of crops. Higher yields were recorded at shorter distances between irrigation pipelines (0.7 and 1.0 m), regardless of the depth of laying. It is proved that the highest level of yield of chickpeas (4.28 t/ha) and sunflower (4.50 t/ha) was obtained by implementing a pulse water supply mode, but this increase was within the error of the experiment. The introduction of underground drip irrigation is more appropriate for the cultivation of chickpeas and sunflower according to the criterion of total energy costs for the technology. The analysis of energy efficiency by the value of the energy efficiency coefficient (EEC) indicates a high level of energy efficiency of chickpea and sunflower cultivation in both ground and ground drip irrigation (EEC=2.03-2.23 and 2.32-2.50, respectively). The most effective method was to grow these crops under a pulse water supply regime: the EEC was 2.44 for growing chickpeas and 2.61 for growing sunflower. The research materials are of practical value for farmers in managing energy consumption in chickpea and sunflower microirrigation technologies. [ABSTRACT FROM AUTHOR]

Sunflower is a major oil crop whose oil is very important in human nutrition as well as for a range of other uses. Grain yield is determined by the plant genetics and it is conditioned by a series of factors among which are counting as important ones the row spacing and plant density. Therefore, find the optimum row spacing and plant density according to cultivated sunflower hybrid and to growing conditions are of interest for sunflower growers. The aim of this paper is to present the results obtained with respect to the sunflower grain yield at different row spacing and plant densities in the specific growing conditions of Romania. Research was performed under field conditions at four sunflower hybrids under different row spacing (70, 60, and 50 cm) and plant densities (50,000, 60,000, and 70,000 plants/ha). The field experiments were located in four locations in East, South-East and South of Romania in three years (2019, 2020, and 2021). The obtained data showed that under favourable growing conditions for sunflower plants, especially under good water plant supply conditions, the highest grain yields are obtained at row spacing of 70 cm, while under less favourable growing conditions for sunflower plants, the narrower rows (at 60 cm and 50 cm) seem to provide better plant growth and finally higher grain yields. Plant density has to be correlated with the growing conditions of the sunflower plants. Thus, the better growing conditions are the higher plant density should be, as to put into value the available growing factors. In the case there is no correlation between the plant density and growing conditions, the plants density too high becomes a limitative yielding factor. [ABSTRACT FROM AUTHOR]

The photosynthetic electron transport chain is mineral rich. Specific mineral deficiencies can modify the electron transport chain specifically. Here, it is shown that on the basis of 2 short Chl fluorescence and P700+ measurements (approx. 1 s each), it is possible to discriminate between 10 out of 12 different mineral deficiencies: B, Ca, Cu, Fe, K, Mg, Mn, Mo, N, P, S, and Zn. B- and Mo-deficient plants require somewhat longer measurements to detect the feedback inhibition they induce. Eight out of twelve deficiencies mainly affect PS I and NIR measurements are, therefore, very important for this analysis. In Cu- and P-deficient plants, electron flow from the plastoquinone pool to PS I, is affected. In the case of Cu-deficiency due to the loss of plastocyanin and in the case of P-deficiency probably due to a fast and strong generation of Photosynthetic Control. For several Ca-, K-, and Zn-deficient plant species, higher levels of reactive oxygen species have been measured in the literature. Here, it is shown that this not only leads to a loss of Pm (maximum P700 redox change) reflecting a lower PS I content, but also to much faster P700+ re-reduction kinetics during the I2-P (~30–200 ms) fluorescence rise phase. The different mineral deficiencies affect the relation between the I2-P and P700+ kinetics in different ways and this is used to discuss the nature of the relationship between these two parameters. [ABSTRACT FROM AUTHOR]

The possibility of accurately assessing the emergence, anthesis and maturation dates of sunflower grown under Mediterranean conditions was investigated. Accumulated Thermal Units (TSUM) from sowing to emergence, from emergence to anthesis, and from anthesis to maturation were recorded in 14 experimental sunflower plantations, carried out in two sites with representative soils in the Thessaly Plain (central Greece) in the years 2012, 2013, 2014, 2015 and 2022. Various combinations of sowing date; irrigation and N-fertilization inputs were studied, and the corresponding phenological stages and seed yields were determined. It was found that the TSUM method is very effective for predicting the duration of the phenological stages of sunflower and thus the development rate and stages of this crop. Particularly accurate is the assessment of the emergence-anthesis period calculated at 817 degree days (°C-d) for base temperature (T o) equal to 6 °C and optimum temperature (T opt) 28 °C, whereas for the anthesis-maturation period, the TSUM method needs to be adjusted for photoperiodism, using a photoperiod coefficient based on the daylength. In a simpler approach, the heat unit sum of 1213°C-d (T o =0 °C) it can be used for the emergence-anthesis period (or 1418°C-d for the sowing-anthesis period), without much error, and an average period of 44 days for the anthesis-maturation period. Having determined the anthesis-maturation period, the potential seed yield of sunflower was successfully assessed, based on the global radiation prevailing during the grain filling period (i.e. last 37 days before capitulum ripening) for the treatments of optimum water and nitrogen applications. Knowledge of the seed yield potential of sunflower might be very important for land evaluation purposes and the introduction of this important crop in Thessaly more generally and many Mediterranean sites. • Capping daily T MAX in sunflower daily thermal units calculations improves anthesis and maturity prediction. • Sunflower heat units needed per stage from sowing: 186°C-days (emergence), 1003°C-days (flowering), 1941°C-days (maturity). • Incorporating photoperiodism into the thermal units model improves the accuracy of sunflower maturity predictions. • Sunflower seed yield increases linearly with PAR at a rate of 0.57 g MJ−1 (yield=0.57*PAR+177 g m−2; R2=0.85). [ABSTRACT FROM AUTHOR]

The continuous increase in the heavy metals concentration in the soil due to anthropogenic activities has become a global issue. The chromium, especially hexavalent chromium, is highly toxic for living organisms due to high mobility, solubility, and carcinogenic properties. Considering the beneficial role of nanoparticles and bacteria in alleviating the metal stress in plants, a study was carried out to evaluate the role of cerium dioxide (CeO2) nanoparticles (NPs) and Staphylococcus aureus in alleviating the chromium toxicity in sunflower plants. Sunflower plants grown in chromium (Cr) contaminated soil (0, 25, and 50 mg kg−1) were treated with CeO2 nanoparticles (0, 25, and 50 mg L−1) and S. aureus. The application of Cerium Dioxide Nanoparticles (CeO2 NPs) significantly improved plant growth and biomass production, reduced oxidative stress, and enhanced the enzymatic activities in the sunflower plant grown under chromium stress. The application of S. aureus further enhanced the beneficial role of nanoparticles in alleviating metal-induced toxicity. The maximum improvement was noted in plants treated with both nanoparticles and S. aureus. The augmented application of CeO2 NPs (50 mg l−1) at Cr 50 mg kg−1 increased the chl a contents from 1.2 to 2.0, chl b contents 0.5 to 0.8 and mg g−1 FW, and decreased the leakage of the electrolyte from 121 to 104%. The findings proved that the application of CeO2 nanoparticles and S. aureus could significantly ameliorate the metal-induced stress in sunflower plants. The findings from this study can provide new horizons for research in the application of nanoparticles in phytoremediation and bioremediation. [ABSTRACT FROM AUTHOR]