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Apomixis (asexual reproduction via seeds) has the potential to revolutionize sunflower breeding. In previous studies, we identified a diploid sunflower line (Rf975) that naturally exhibits extra gametophytes resembling aposporous apomictic embryo sacs (AES). Here, we investigated the nature (reduced vs. unreduced) and viability of these AES-like gametophytes by examining the formation of triploid (3x) BIII hybrids (2n + n) in the progeny of Rf975. Flow cytometry analysis of immature seeds revealed that, on average, 42.8% of self-pollinated Rf975 progeny were triploids, although only 36.6% of them reached maturity. Cytoembryological analysis showed that 100% of triploids exhibited some degree of apospory, with an average expressivity of 61.9%. Abnormal pollen grains and limited viable seeds were also noted. A segregant F2 progeny, comprising diploid and triploid individuals, was generated by crossing Rf975 with HA89, a genetically divergent sexual diploid. SNP-based progeny tests discarded that diploid Rf975 forms clonal matroclinal progeny at levels greater than 18%. Furthermore, specific non-random genetic and DNA methylation changes were detected in the F2 triploids compared to F2 diploids and parental plants, highlighting recurrent (epi)genetic alterations occurring during triploidization. This research could contribute to the future implementation of apomixis-based strategies in sunflower breeding. [ABSTRACT FROM AUTHOR]

Sunflower serves as a valuable rotational crop, suitable for snack processing or sunflower seed oil extraction, proving to be a lucrative cash crop. To address sunflower yield uncertainties, this study employs meta-analysis to examine the impact of fertilisation. Utilising 41 studies and 392 pairs of observations based on four criteria, we found an overall 27% increase in sunflower yield with fertiliser application. Nitrogen (N), phosphorus (P), and potassium (K) individually applied raised yield by 23.37, 20.92, and 11.63%, respectively. Combined fertilisers (NP, NK, NP, and NPK) enhanced yield by 29.69, 28.40, 17.35, and 41.91%, respectively. Sunflower type minimally affects yield, while planting density significantly influences it. Combining local soil conditions and environmental factors with appropriate planting densities ensures maximum sunflower yield, fostering economic benefits for farmers. This study holds constructive implications for sunflower cultivation in China, contributing to increased yield. [ABSTRACT FROM AUTHOR]

Different floral traits mediate interactions between plants and their visitors. Capitates Glandular Trichomes (CGT) can attract or repel visitors, particularly arthropods. In Helianthus annuus L., CGTs are located at the distal ends of the anther appendages. This study aimed to determine whether the presence of CGTs influences the behaviour of diurnal floral visitors under field conditions by comparing genotypes with high and low CGT density per anther, while maintaining similar phenotypic characteristics. The analysis accounted for three random variables -floral developmental stages (R5.3, R5.6, and R6), daytime ranges (morning, midday, and afternoon), and two flowering seasons- to better understand variations in CGT mediated floral arthropod interactions. Key recorded species included Astylus atromaculatus (Blanchard) (Coleoptera Melyridae), Apis mellifera L. (Hymenoptera Apidae), and species from the Thomisidae family representing herbivores, pollinators, and insect-predators, respectively. The genotype with a high CGT density received fewer herbivore visits and more pollinator visits compared with the genotype with a low CGT density. Predators did not exhibit genotype-related differences but reduced bee presence by 20% probably due to Thomisidae spiders preying on bees. Furthermore, the inclusion of random variables enhanced the models. Herbivore abundance varied significantly between flowering seasons, while pollinator abundance fluctuated across the daytime ranges. Both herbivores and pollinators also showed variations in abundance across the reproductive stages, likely influenced by the proportion of disc floret phenophases and the CGTs' secretory stage. This study underscores the importance of CGTs as a key morphological feature with potential implications for plant reproduction, justifying broader, more extensive investigations. It also emphasizes the necessity of considering multiple factors in plantarthropod interactions research. [ABSTRACT FROM AUTHOR]

Background. The study is of particular importance in view of the increasing pace of global climate aridization. The article highlights the results of an experiment on the effect of drought on the physiological status of seedlings of cv. ‘Poseidon 625’ representing an important food crop – sunflower (Helianthus annuus L.). Materials and methods. The experiment included a group of control samples grown with sufficient moisture and four impact groups subjected to osmotic stress. The intensity of accumulation of lipid peroxidation products (LPP) was measured by the reaction of malondialdehyde (MDA) with thiobarbeturic acid; catalase activity was assessed by a photocolorimetric method based on the interaction between hydrogen peroxide and potassium iodide; the content of pigments (Chl a, Chl b, Сar) was calculated spectrophotometrically in acetone extract. Results. The degree of POL accumulation in the impact groups of the experiment was found to be many times higher than the values in the control samples, which was confirmed by a rapid increase in the MDA concentration in response to a growing water shortage. The accumulation of oxygen free radicals triggered the mechanisms of antioxidant protection of seedlings by synthesizing catalase, the concentration of which increased proportionally to the accumulation of POL. At the same time, the rapid accumulation of POL in the absence of irrigation and under osmotic stress of 3 and 5 atm led to a suppression of low-molecular-weight components of protection (carotenoids) and activation of their synthesis only when critical values of osmotic stress were reached. Conclusion. As a result of the experiment, catalase was identified as the main component of antioxidant protection in sunflower seedlings. Due to the activation of its synthesis, the concentrations of Chl a and Chl b decreased, attesting to the activation of the mechanisms protecting the photosynthetic activity in seedlings, and their antioxidant status.

The aim of our study was to explore the antioxidant potential of Moroccan saffron stigmas (SS) and examine their performance as a natural antioxidant in enhancing the stability and quality properties of edible sunflower oil (SO), with a focus on understanding the critical importance of edible oil stability for predicting quality deterioration during storage. Bearing this in mind, our research was designed to compare the efficacy of three concentrations of dried SS (at 0.2%, 0.3%, and 0.6%) against tocobiol (a synthetic antioxidant) as a positive control (at 0.3% concentration). This comparison was conducted under three distinct storage conditions namely accelerated ageing (60 °C), exposure to light at ambient temperature, and darkness, to evaluate their impact on preventing severe oxidation and extending oil shelf-life. Oxidation state evolution was evaluated through peroxide value (PV), free fatty acid (FFA), anisidine value (p-AV), K270 value (conjugated trienes), total oxidation index (TOTOX), iodine value (IV), and fatty acid composition (FA). Our results revealed notable differences in stability tracking parameters. Specifically, these parameters were higher in samples stored under accelerated conditions, followed by the samples stored in ambient light, while those stored in darkness showed the highest stability among the three storage conditions. Supplementation of sunflower oil with SS and tocobiol significantly enhanced its oxidation stability. Notably, SS exhibited exceptional effectiveness in stabilizing sunflower oil regardless of SS dose, with the highest efficacy observed at 0.6%. This was evidenced by the slower rate of oxidation parameters under various storage conditions, highlighting a superior antioxidant activity compared to both the non-enriched oil and tocobiol-enriched oil. Furthermore, saffron stigmas, used as a natural supplement, contributed to the preservation of polyunsaturated fatty acids, indicating its potential as a robust source of natural antioxidants in sunflower oil. These attributes position SS as a promising alternative to synthetic antioxidants, offering opportunities to enhance the nutritional quality and extend edible oil shelf-life.

Copyright of Revista Nutrición Clínica y Dietética Hospitalaria is the property of Sociedad Espanola de Dietetica y Ciencias de la Alimentacion and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cultivation of sunflower (Helianthus annuus L.) as a cut flower stands out in floriculture due to its aesthetic beauty and commercial value. Understanding how cut sunflower genotypes adapt to different edaphoclimatic regions and management practices is essential to optimize flower quality and productivity. This study aimed to evaluate the effect of plant density and location on the development, growth, and quality of cut sunflower in tropical and subtropical environments. Plant densities of 10, 20, 30, 40, and 50 plants/m2 were evaluated in tropical climate and subtropical climate using a randomized block design in a factorial scheme. Results showed significant differences between locations for plant height, capitulum and stem diameter, final number of leaves, leaf area, leaf area index, phyllochron, and the developmental cycle. Plant density significantly influenced these variables except for plant height and developmental cycle. The interaction between location and plant density was significant only for capitulum diameter and final leaf number. The findings indicate that both planting density and location significantly influence the developmental cycle of cut sunflowers, with lower densities favoring more robust plants at harvest. A density of 30 plants/m2 is recommended for efficient space use without significantly compromising floral stem quality. All produced stems are marketable, suggesting that adjusting planting density can optimize production without compromising quality, adapting to specific regional conditions. [ABSTRACT FROM AUTHOR]

The state of Rio Grande do Sul (RS) is the third largest sunflower producer in Brazil. This study verified the existence of linear relationships between grain yield, oil content, and oil yield in sunflower (Helianthus annuus L.) genotypes evaluated in RS. The data on grain yield (GY), oil content (OC), and oil yield (OY) were obtained from 73 sunflower cultivar trials in 21 municipalities in RS from 1999 to 2018. Scatter diagrams were createdto investigate the relationships between the variables GY, OC, and OY. Then, Pearson's linear correlation coefficient (r) was calculated between the variables, and the Student's t-test was performed at a 5% significance level. There is a positive and significant linear relationship between PG and OY. However, no linear relationship was found between grain yield and oil content in sunflower genotypes. Additionally, a positive linear association of high magnitude (r = 0.9672) was observed between grain yield and oil yield, while a low magnitude (r = 0.2245) was found between oil content and oil yield. [ABSTRACT FROM AUTHOR]

The aim of our study was to explore the antioxidant potential of Moroccan saffron stigmas (SS) and examine their performance as a natural antioxidant in enhancing the stability and quality properties of edible sunflower oil (SO), with a focus on understanding the critical importance of edible oil stability for predicting quality deterioration during storage. Bearing this in mind, our research was designed to compare the efficacy of three concentrations of dried SS (at 0.2%, 0.3%, and 0.6%) against tocobiol (a synthetic antioxidant) as a positive control (at 0.3% concentration). This comparison was conducted under three distinct storage conditions namely accelerated ageing (60 °C), exposure to light at ambient temperature, and darkness, to evaluate their impact on preventing severe oxidation and extending oil shelf-life. Oxidation state evolution was evaluated through peroxide value (PV), free fatty acid (FFA), anisidine value (p-AV), K270 value (conjugated trienes), total oxidation index (TOTOX), iodine value (IV), and fatty acid composition (FA). Our results revealed notable differences in stability tracking parameters. Specifically, these parameters were higher in samples stored under accelerated conditions, followed by the samples stored in ambient light, while those stored in darkness showed the highest stability among the three storage conditions. Supplementation of sunflower oil with SS and tocobiol significantly enhanced its oxidation stability. Notably, SS exhibited exceptional effectiveness in stabilizing sunflower oil regardless of SS dose, with the highest efficacy observed at 0.6%. This was evidenced by the slower rate of oxidation parameters under various storage conditions, highlighting a superior antioxidant activity compared to both the non-enriched oil and tocobiol-enriched oil. Furthermore, saffron stigmas, used as a natural supplement, contributed to the preservation of polyunsaturated fatty acids, indicating its potential as a robust source of natural antioxidants in sunflower oil. These attributes position SS as a promising alternative to synthetic antioxidants, offering opportunities to enhance the nutritional quality and extend edible oil shelf-life. [ABSTRACT FROM AUTHOR]

The present investigation was performed to evaluate the effects of various synthetic antioxidants (vitamin A, vitamin E, β-carotene, and BHT) on the oxidation of sunflower oil subjected to accelerated thermal storage at 60 °C for three months (12 weeks). The performance of the antioxidants studied was evaluated using several quality parameters: the free fatty acid value (FFA), primary oxidation (via the peroxide value (PV) and K232 value), secondary oxidation products (via the anisidine value (p-AV) and K270 value), and the total oxidation value (TOTOX). The fatty acid composition (FAC), oxidizability value (COX), iodine value (IV), and pigment content (chlorophyll and carotenoid) were also evaluated. The results revealed that the control sample of sunflower oil exhibited higher susceptibility to oxidative deterioration. Antioxidants at 200 ppm were more effective in preserving the oxidative stability of sunflower oil subjected to accelerated storage compared to the control oil. The smallest increases in all stability parameter indexes were recorded for antioxidant-supplemented sunflower oil. However, the IV and chlorophyll and carotenoid contents were reduced. At 200 ppm, vitamin E and β-carotene showed the greatest stability in sunflower oil, while their combination with vitamin A at 100 ppm of each showed the lowest stability. In addition, synthetic antioxidants provided greater protection against the degradation of polyunsaturated fatty acids (PUFAs). The highest level of PUFA degradation was recorded in the control oil, followed by the oil containing vitamin A. In conclusion, adding synthetic antioxidants to sunflower oil improves its stability during storage. However, some authors associated these molecules with a health risk due to carcinogenic effects as these molecules have been listed as “Generally Recognized As Safe” (GRAS).

This study was conducted to investigate the potential of using the germination test as a model for screening imazamox resistance in sunflower plants . A standard germination test was performed by applying different doses of imazamox (control, 0.1, 0.2, 0.4, 0.8, and 1.6 mM) to imidazoline-resistant (IMI-R) and susceptible (IMI-S) sunflower hybrids. Germination percentage, mean germination time, germination index, shoot length, root length, seedling fresh and dry weight, and phytotoxicity percentage for seedling growth parameters were investigated. The results showed that imazamox concentrations slightly affected the germination percentage of two sunflower hybrids at only 1.6 mM. Increasing doses of imazamox led to an increase in the mean germination time and a decrease in the germination index for both sunflower hybrids, following a similar trend. Seedling growth parameters such as shoot length, root length, and seedling fresh weight were significantly decreased by increasing imazamox doses. In addition, the differences between IMI-R and IMI-S sunflower hybrids were very evident for these parameters. The IMI-S sunflower hybrid showed sensitivity in the presence of imazamox, while no changes in the IMI-R hybrid were determined up to 0.4 mM. The inhibition percentage was higher in the IMI-S hybrid than in the IMI-R. It was concluded that the optimal dose of imazamox for the selection of resistant plants during the early growth stage was found to be 0.2 mM. The germination parameters were not good criteria for imazamox resistance, while root length, shoot length, and seedling fresh weight should be considered as selection criteria for resistance to imazamox in sunflower. [ABSTRACT FROM AUTHOR]

Plant growth-promoting rhizobacteria (PGPR) support plant growth through direct and indirect mechanisms. To investigate PGPR strains that support plant growth, 21 bacterial isolates, mostly Bacillus ssp. and Pseudomonas ssp., were isolated from different rhizospheric soils of sunflowers in Kırşehir districts in 2020. All isolates were characterized morphologically, biochemically by screening under in vitro conditions for plant growth-promoting properties such as nitrogen fixation, IAA (indoleacetic acid) production, siderophore production, HCN (hydrogen cyanide) production, inorganic phosphate solubility. It was also screened for extracellular enzyme production and antifungal activity against Fusarium oxysporum. Among the 21 isolates, 3 isolates (MH-35-4, MH-49-4, MH-64-3) fixed nitrogen, 2 isolates (MH-59-6, MH-64-3), produced siderophores, 8 isolates (MH-35-4, MH-35-6, MH-54-3, MH-54-4, MH-59-1, MH-59-2, MH-59-4, MH-59-8) produced HCN, 6 isolates (MH-35-6, MH-54-4, MH-59-1, MH- 59-2, MH-59-4, MH-59-8) produced IAA, and 7 isolates (MH-35-4, MH-35-6, MH-59-1, MH-59-2, MH-59-4, MH-59-8, MH-64-3) solubilized inorganic phosphate. Additionally, only 2 isolates (MH-54-3, MH-54-4) were positive amylase tests, 8 isolates (MH-35-6, MH-54-4, MH-59-1, MH-59-2, MH-59-4, MH-59-6, MH-59-7, MH-59-8) were positive citrate tests, 8 isolates (MH-35-1, MH-35-4, MH-35-7, MH-49-4, MH-54-4, MH-59-6, MH-59-7, MH-64-3) were positive protease tests, and 6 isolates (MH-35-1, MH-35-3, MH-35-7, MH-54-3, MH-54-4, MH-59-7) were positive gelatin hydrolysis tests. Among 21 isolates, 38% were determined as hydrogen cyanide producers, 10% as siderophore producers, 29% IAA producers, 33% as phosphate solubilizers and 14% as nitrogen fixers. Isolate MH-35-6 showed the highest antifungal activity against Fusarium oxysporum with an inhibition rate of 53.57%. This was followed by isolates MH-54-1 (51.19%), MH-54-3 (47.61%) and MH-59-2 (38.09%), respectively. Therefore, our study reveals that bacteria that promote plant growth in sunflowers can be used to increase crop yield and as a biocontrol agent. [ABSTRACT FROM AUTHOR]

The present investigation was performed to evaluate the effects of various synthetic antioxidants (vitamin A, vitamin E, β-carotene, and BHT) on the oxidation of sunflower oil subjected to accelerated thermal storage at 60 °C for three months (12 weeks). The performance of the antioxidants studied was evaluated using several quality parameters: the free fatty acid value (FFA), primary oxidation (via the peroxide value (PV) and K232 value), secondary oxidation products (via the anisidine value (p-AV) and K270 value), and the total oxidation value (TOTOX). The fatty acid composition (FAC), oxidizability value (COX), iodine value (IV), and pigment content (chlorophyll and carotenoid) were also evaluated. The results revealed that the control sample of sunflower oil exhibited higher susceptibility to oxidative deterioration. Antioxidants at 200 ppm were more effective in preserving the oxidative stability of sunflower oil subjected to accelerated storage compared to the control oil. The smallest increases in all stability parameter indexes were recorded for antioxidant-supplemented sunflower oil. However, the IV and chlorophyll and carotenoid contents were reduced. At 200 ppm, vitamin E and β-carotene showed the greatest stability in sunflower oil, while their combination with vitamin A at 100 ppm of each showed the lowest stability. In addition, synthetic antioxidants provided greater protection against the degradation of polyunsaturated fatty acids (PUFAs). The highest level of PUFA degradation was recorded in the control oil, followed by the oil containing vitamin A. In conclusion, adding synthetic antioxidants to sunflower oil improves its stability during storage. However, some authors associated these molecules with a health risk due to carcinogenic effects as these molecules have been listed as "Generally Recognized As Safe" (GRAS). [ABSTRACT FROM AUTHOR]

The reason for this examination is today's wide usage of chlorophyll a fluorescence (ChlF) among researchers worldwide to measure photosynthetic efficiency. Although the instructions of the ChlF measuring device clearly emphasize the need for methodology adjustments, depending on the specific plant species, many researchers use the usual 30 min of dark adaptation before measurement. Namely, before any ChlF measurement, it is necessary to determine the specific duration of the leaf adaptation to the conditions of darkness of each plant tissue. Because of the numerous uses of the ChlF measurements, we decided to conduct this research to determine whether the appearance of the curves and parameter values depend on the time of sunflower leaf tissue adaptation to dark conditions. Therefore, this research aimed to examine the optimal adaptation time of sunflower tissue to dark conditions to obtain timely precise measurements and credible appearance of ChlF transient curves as well as accurate parameter values. The research was carried out on the sunflower hybrid Luka with 0, 15, 30, 45, 60, 75 and 90 min of dark adaptation in the vegetative, budding and flowering stages in the field conditions. According to the analyzed transient curves and parameters, it was determined that sunflower leaves should be kept in dark conditions for at least 15 min before the measurement of ChlF, which leads to the complete oxidation of PSII and the electron transport chain prior to a saturating pulse of light. [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]

Sunflower (Helianthus annuus L.) is an important, substantial global oil crop with robust resilience to drought and salt stresses. The TGA (TGACG motif-binding factor) transcription factors, belonging to the basic region leucine zipper (bZIP) family, have been implicated in orchestrating multiple biological processes. Despite their functional significance, a comprehensive investigation of the TGA family's abiotic stress tolerance in sunflowers remains elusive. In the present study, we identified 14 TGA proteins in the sunflower genome, which were unequally distributed across 17 chromosomes. Employing phylogenetic analysis encompassing 149 TGA members among 13 distinct species, we revealed the evolutionary conservation of TGA proteins across the plant kingdom. Collinearity analysis suggested that both HaTGA01 and HaTGA03 were generated due to HaTGA08 gene duplication. Notably, qRT-PCR analysis demonstrated that HaTGA04, HaTGA05, and HaTGA14 genes were remarkably upregulated under ABA, MeJA, and salt treatments, whereas HaTGA03, HaTGA06, and HaTGA07 were significantly repressed. This study contributes valuable perspectives on the potential roles of the HaTGA gene family under various stress conditions in sunflowers, thereby enhancing our understanding of TGA gene family dynamics and function within this agriculturally significant species. [ABSTRACT FROM AUTHOR]

This article examines the relationship between sunflower plants and the parasitic plant broomrape. The study reveals that broomrape infiltrates sunflower roots by entering the host cells, creating a new compartment. The researchers also observed cell divisions in the sunflower roots near the attachment sites, potentially leading to root enlargement. The study suggests that the parasitic plant damages the host cell walls with enzymes, but the host plants only exhibit minimal defense responses. These findings contribute to our understanding of parasitic plant interactions and may aid in the development of resistance strategies. [Extracted from the article]

The cultivation of sunflower (Helianthus annuus L.) as a cut flower stands out in floriculture due to its aesthetic beauty and commercial value. Understanding how cut sunflower genotypes adapt to different edaphoclimatic regions and management practices is essential to optimize flower quality and productivity. This study aimed to evaluate the effect of plant density and location on the development, growth, and quality of cut sunflower in tropical and subtropical environments. Plant densities of 10, 20, 30, 40, and 50 plants/m2 were evaluated in tropical climate and subtropical climate using a randomized block design in a factorial scheme. Results showed significant differences between locations for plant height, capitulum and stem diameter, final number of leaves, leaf area, leaf area index, phyllochron, and the developmental cycle. Plant density significantly influenced these variables except for plant height and developmental cycle. The interaction between location and plant density was significant only for capitulum diameter and final leaf number. The findings indicate that both planting density and location significantly influence the developmental cycle of cut sunflowers, with lower densities favoring more robust plants at harvest. A density of 30 plants/m2 is recommended for efficient space use without significantly compromising floral stem quality. All produced stems are marketable, suggesting that adjusting planting density can optimize production without compromising quality, adapting to specific regional conditions.

If appropriately applied, tillage can positively affect the crop's yield by enhancing the soil's physical properties. Fertilisation also has beneficial effects on yield if applied at efficient rates by increasing available-to-uptake nutrients and improving soil's chemical properties. A field experiment was carried out in Debrecen, Hungary, to evaluate the individual and the interaction effects of these 2 factors on sunflower and sweet corn. The cultivation methods applied were ploughing (C1), direct drilling (C2) and deep loosening (C3). In addition, 3 fertilisation rates were applied to each cultivation system: F1 (control, no fertilisation); F2 (100:50:70) kg NPK/ha and F3 (150:100:120) kg NPK/ha in a randomised complete block design (RCBD) with 4 replicates. Our results showed that fertilisation did not affect the yield of sweet corn measurably. However, C1 resulted in the highest yield, whereas C2 and C3 resulted in relatively similar yields. In sunflowers, the yields of both C1 and C2 were higher than that of C3. No significant differences were recorded between C1 and C2. The yields of both F2 and F3 were higher than the yield of F1. The differences between F2 and F3 were insignificant. It could be concluded that the cultivation method is a determining factor in the yield of sweet corn. The effects of both fertilisation and cultivation treatments were more detectable in sunflowers. The differences between the two fertilisation rates (F2 and F3) were insignificant in both species, indicating that the extra fertilisation levels might be unnecessary.

Sunflower growth is adversely impacted by both excess and insufficient water. Research on root growth in this crop under water stress conditions remains limited and does not fully elucidate the plant's response to varying soil and climatic conditions. This study aimed to determine root growth, depth, and distribution of sunflower plants under different water stress conditions, such as deficit or excess, in two soil classes and sown during two distinct periods. Experiments were conducted after sowing at the beginning of September (first crop season) and at the beginning of January (second crop season) in an Ultisol (Santa Maria, Rio Grande do Sul State, Brazil) and an Oxisol (Panambi, Rio Grande do Sul State, Brazil). Water condition treatments applied from stage V6 included control, water deficit, and water excess. Roots were collected using an auger drill during the first crop season. The variables analyzed comprised root length density and accumulated root within the soil profile. During the second crop season, sunflower roots were visually assessed in the soil profile after trench excavation. Root system depth and root dry mass were evaluated during both sowing periods. Results indicated that sunflower root penetration is deeper in Ultisol than in Oxisol. Water deficit promotes root depth, while water excess promotes root growth near the surface. Sowing during the first crop season results in deeper root penetration and higher root dry mass production compared to the second crop season.

Sunflower growth is adversely impacted by both excess and insufficient water. Research on root growth in this crop under water stress conditions remains limited and does not fully elucidate the plant's response to varying soil and climatic conditions. This study aimed to determine root growth, depth, and distribution of sunflower plants under different water stress conditions, such as deficit or excess, in two soil classes and sown during two distinct periods. Experiments were conducted after sowing at the beginning of September (first crop season) and at the beginning of January (second crop season) in an Ultisol (Santa Maria, Rio Grande do Sul State, Brazil) and an Oxisol (Panambi, Rio Grande do Sul State, Brazil). Water condition treatments applied from stage V6 included control, water deficit, and water excess. Roots were collected using an auger drill during the first crop season. The variables analyzed comprised root length density and accumulated root within the soil profile. During the second crop season, sunflower roots were visually assessed in the soil profile after trench excavation. Root system depth and root dry mass were evaluated during both sowing periods. Results indicated that sunflower root penetration is deeper in Ultisol than in Oxisol. Water deficit promotes root depth, while water excess promotes root growth near the surface. Sowing during the first crop season results in deeper root penetration and higher root dry mass production compared to the second crop season. [ABSTRACT FROM AUTHOR]

A large amount of sunflower production is carried out in our country. The 2,500,000 tons of sunflower stalks that appeared after production pose a problem for our farmer. In order to clean up this environmental problem from the field, sunflower stalks are destroyed by burning to warm up in winter, broken down and mixed into the soil, or burned after harvesting. It is thought that by obtaining qualified, ecological and naturally decomposing sunflower fiber from the stem of the sunflower plant, which is an agricultural waste, it can increase the added value of agricultural products and contribute to the protection of the environment. In this study, the anatomical characteristics of the stem of the sunflower plant were determined, and natural lignocellulosic fibers were obtained from the sunflower stem by retting and decortication methods (fresh stem, dried stem). Various physical, chemical and mechanical properties of these fibers have been measured. For this purpose, FTIR (Fourier Transform Infrared Spectroscopy) analysis, XRD (X-Ray Diffractometer) analysis and SEM (Scanning Electron Microscope) analysis were applied to the fibers obtained by different methods. Thermal analyses were performed by TG-DTA (Thermogravimetric) analysis. In addition, fiber strength, fiber fineness, fiber length and color measurements were made. The chemical content of the obtained fibers (pectin, lignin, cellulose, hemicellulose) was determined. The properties of the fibers were compared using the obtained data. As a result of the study, it has been seen that the characteristic properties of the sunflower fibers obtained by the retting method are better. It has been determined that the elemental, thermal and crystal structures of the fibers obtained by different methods are similar. It was concluded that sunflower fiber will not be spun as a yarn, but can be used as a natural polymeric composite reinforcement material. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to study the oxidation resistance and functional properties of oleogels based on high oleic oil and wax from Helianthus annuus L. with the addition of a natural complex antioxidant — an extract from Rosmarinus officinalis L. and lecithin from Helianthus annuus L. — when used as a frying medium for French-fries. High oleic sunflower oil was structured into an oleogel with sunflower wax at a dosage of 5%. Studies were carried out to determine the possibility of replacing the synthetic antioxidant tert-butylhydroquinone at a dosage of 200 mg/kg with a natural antioxidant based on rosemary extract and sunflower lecithin in an oleogel with a defoamer. It was determined that the introduction of sunflower wax increased the induction period of high-oleic sunflower oil by 1.6 times, and the additional introduction of defoamer and antioxidants increased this figure by 1.8–2 times. The rate of accumulation of oxidation products in oil, which is characterized by the level of total polar materials, decreased when wax and antioxidants were added. The degree of thermal oxidation most quickly reached the limit value in oil without additives; in oleogels, it significantly decreased. The introduction of sunflower wax into oil contributed to a noticeable decrease in the absorption of oil by potatoes: fried in oleogel, it absorbed 34–38% less oil than fried in oil without additives. The addition of 0.07% rosemary extract with sunflower lecithin to the oleogel increased the operating time of frying oil by at least 2 times, approximately the same as that of the oleogel with tert-butylhydroquinone. This makes it possible to replace the synthetic antioxidant in deepfrying oleogel with natural rosemary extract with sunflower lecithin. The developed oleogel is a frying oil that has a longer service life and allows you to get fried products with a lower amount of fat.

Chemical fertilization of soils has been adopted as a productivity-boosting mode for many years but it is marked by excessive synthetic chemical utilization and significant persistence in the ecological matrices. Current research has for the first adopted a cost-effective, eco-friendly, and sustainable mode of soil fertilization and consequent growth augmentation of Helianthus annuus by utilization of kitchen waste and garden waste-based processed compost. Comparative analysis of the prepared compost with chemical fertilizer expressed a profound responsiveness of the soils towards compost in pot experiments conducted at Rawalpindi, Pakistan for assessment of soil quality after modification with compost. Soil amendments were varied including compost amended soil (CAS), di-ammonium phosphate amended soil (DAS), urea amended soil(UAS), and control soil (CS). Organic matter of CAS i.e. 4.67% and 4.91% and micro and macro nutrients excelled in other amendments signifying the potential of CAS to be adopted as a future green manure as an effective substitute to chemical fertilizers. Heavy metals i.e. Ni, Zn, Pb, and Cu concentration determination of soil treatments expressed a slightly higher trend but within permissible limits. Helianthus annuus grown in treated soils expressed outstanding phyto-morphological aspects in CAS and UAS. Composting as an organic fertilizer provides a cost-effective, ecologically friendly, and sustainable way to improve soil fertility. As a result, high-quality, reasonably priced compost will be produced, offering a practical and efficient waste disposal alternative.

Sunflowers belong to the Asteraceae family, which comprises nutrimental and economic oilseed plants. Heat shock proteins (Hsps) are protein families vital for all organisms' growth and survival. Besides the ordinary conditions, the expression of these proteins ascends during abiotic stress factors such as high temperature, salinity, and drought. Using bioinformatics approaches, the current study identified and analyzed HSF and Hsp gene family members in the sunflower (Helianthus annuus L.) plant. HSF, sHsp, Hsp40, Hsp60, Hsp70, Hsp90, and Hsp100 domains were analyzed in the sunflower genome, and 88, 72, 192, 52, 85, 49, and 148 genes were identified, respectively. The motif structures of the proteins in the same phylogenetic tree were similar, and the α-helical form was dominant in all the protein families except for sHsp. The estimated three-dimensional structure of 28 sHsp proteins was determined as β-sheets. Considering protein-protein interactions, the Hsp60-09 protein (38 interactions) was found to be the most interacting protein. The most orthologous gene pairs (58 genes) were identified between Hsp70 genes and Arabidopsis genes. The expression analysis of selected genes was performed under high temperature, drought, and high temperature-drought combined stress conditions in two sunflower cultivars. In stress conditions, gene expressions were upregulated for almost all genes in the first half and first hours at large. The expressions of HanHSF-45 and HanHsp70-29 genes were raised in two cultivars under high temperature and high temperature-drought combined stress conditions. This study presents a blueprint for subsequent research and delivers comprehensive knowledge of this vital protein domain. [ABSTRACT FROM AUTHOR]

Plant growth is complex, and involves many processes and its understanding is essential to maximize the crop's potential. The use of modeling is an essential tool to characterize the plant's growth and development, in addition, generates strategies for future plantings, adapting the management. Therefore, this study aimed to apply and make considerations based on parameters of the Logistic and Gompertz models to the fresh plants mass, of three sunflower cultivars, sown in three seasons, and select the best model for the cultivars. The data used came from nine uniformity trials with the sunflower cultivars Aguará 6, Nusol 4510, and Rhino and were adjusted according to the accumulated growing degree days, using the Logistic and Gompertz models. Parameters were estimated using the methods of ordinary least squares (OLS) and generalized least squares (GLS). In the presence of violations, the power method was used to structure the variance. Fit quality of the models to the data was assessed by the adjusted determination coefficient, Akaike information criterion, and Schwarz's Bayesian criterion. Logistic and Gompertz models fitted the data, converging on interpretable parameters, both by OLS and GLS methods. The insertion of the power structure into the models resulted in a better fit for the data. The cultivars Aguará 6 and Nusol 4510 are best described by the Logistic model and present a higher positive growth phase in the first trial. The sunflower cultivar Rhino is best described by the Gompertz model and presents a reduction in the positive growth phase in the first trial. [ABSTRACT FROM AUTHOR]

If appropriately applied, tillage can positively affect the crop's yield by enhancing the soil's physical properties. Fertilisation also has beneficial effects on yield if applied at efficient rates by increasing available-to-uptake nutrients and improving soil's chemical properties. A field experiment was carried out in Debrecen, Hungary, to evaluate the individual and the interaction effects of these 2 factors on sunflower and sweet corn. The cultivation methods applied were ploughing (C1), direct drilling (C2) and deep loosening (C3). In addition, 3 fertilisation rates were applied to each cultivation system: F1 (control, no fertilisation); F2 (100: 50: 70) kg NPK/ha and F3 (150: 100: 120) kg NPK/ha in a randomised complete block design (RCBD) with 4 replicates. Our results showed that fertilisation did not affect the yield of sweet corn measurably. However, C1 resulted in the highest yield, whereas C2 and C3 resulted in relatively similar yields. In sunflowers, the yields of both C1 and C2 were higher than that of C3. No significant differences were recorded between C1 and C2. The yields of both F2 and F3 were higher than the yield of F1. The differences between F2 and F3 were insignificant. It could be concluded that the cultivation method is a determining factor in the yield of sweet corn. The effects of both fertilisation and cultivation treatments were more detectable in sunflowers. The differences between the two fertilisation rates (F2 and F3) were insignificant in both species, indicating that the extra fertilisation levels might be unnecessary. [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]

Sunflower (Helianthus annuus L.) and African palm kernel (Elaeis guineensis Jacq.) are among the most cultivated in the world regarding oil extraction. The oil industry generates a large amount of meal as a by-product, which can be a source of nutrients and bioactive compounds. However, the physiological effects of bioactive compounds in such matrices are only valid if they remain bioavailable and bioactive after simulated gastrointestinal digestion. This study evaluated the chemical composition and antioxidant and prebiotic potential of de-oiled sunflower (DS) and de-oiled palm kernel (DP) meal after in vitro digestion. The DS sample had the highest protein content and the best chemical score, in which lysine was the limiting amino acid. Digested samples showed increased antioxidant activity, measured by in vitro methods. The digested DS sample showed a better antioxidant effect compared to DP. Moreover, both samples managed to preserve DNA supercoiling in the presence of the oxidizing agent. The insoluble fractions after digestion stimulated the growth of prebiotic bacterium, similar to inulin. In conclusion, simulated gastrointestinal digestion promoted in both matrices an increase in protein bioaccessibility and antioxidant capacity, pointing to a metabolic modulation favorable to the organism. [ABSTRACT FROM AUTHOR]

The presence of weeds in the sunflower crop is one of the main factors linked to the low increase in productivity of this crop, and to determine the most appropriate management of weeds, it is essential to carry out a diagnosis through the phytosociological survey. The objective of this study was to assess the influence of chemical control on the phytosociological community of weeds in three areas cultivated with sunflower in the Parecis region (Brazil). The areas were treated with 2,4-D + glyphosate for desiccation; S-metolachlor was used for pre-emergence control in the three areas; meanwhile, sulfentrazone and flumioxazin were applied only in one area; and, finally, clethodim was applied for post-emergence weed management. Sampling was carried out at two different times, in the initial and pre-harvest stages (at 35 and 100 days after the emergence of the crop, respectively), using a quadrate, in which weeds were identified and quantified to determine the frequency, relative frequency, density, relative density, abundance, relative abundance, importance index, and similarity index between areas and times. Seventeen weed species were found in the sunflower crop (70.6% dicot and 29.4% monocotyledonous) in the two seasons, grouped into nine botanical families, with Poaceae being the most diverse family. The dicots Tridax procumbens and Acanthospermum hispidium were present in low frequency only in the initial stages of development of the sunflower crop. The weeds with the highest importance index values in the initial and pre-harvest stages were Euphorbia hirta (104 and 91%) and Bidens pilosa (45 and 66%, respectively), both belonging to the dicots group. These two species were present in the two evaluated periods and in the three experimental areas, demonstrating that there was a similarity index between them with values above 93%. These results of the phytosociological study may contribute to determining more efficient management strategies for weed chemical control in the sunflower crop.

The sunflower (Helianthus annuus L.) is an oleaginous plant that shows high suitability for cultivation in Brazil. However, the performance of the crop is influenced by factors such as weed interference, mainly because of the few selective herbicide options. Thus, the objective of this study was to evaluate weed control and selectivity of four pre-emergent herbicides applied to two sunflower cultivars in sandy and clayey soils. Two field experiments were conducted in a randomized block design with a 2 × 6 factorial scheme, two cultivars (CF 101 and M 734) and six treatments with S-metolachlor (1920 g a.i. ha−1), sulfentrazone (150 g a.i. ha−1), flumioxazin (40 g a.i. ha−1), and trifluralin (1780 g a.i. ha−1) and two controls, one with weeding and the other without weeding and without herbicide application, in soils with contrasting textures (sandy and clayey). No injury symptoms were observed in both cultivars, regardless of soil texture. The cultivar M 734 exhibited the highest values of the agronomic parameters evaluated. The treatment with flumioxazin provided control of more than 90% of the weeds in clayey soil and more than 64% in sandy soil. The yield of both cultivars was lower in the sandy soil. Thus, all herbicide treatments were selective for both cultivars tested, since they did not interfere with sunflower grain yield.

The breeding of high-yielding sunflower varieties and hybrids requires the use of parent material with considerable genetic diversity. It can be identified using molecular genetic markers. The purpose of this study was the genotyping of sunflower lines bred by V. S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK), developed in different ecological areas of cultivation, and to evaluate their genetic diversity using microsatellite loci. For the studies conducted in 2020-2022, there were used 23 lines from the Central experimental base (СEB), 17 lines from L.A. Zhdanov Don experimental station (DES), and 10 lines from the Armavir experimental station (AES). DNA was isolated from seedlings by the CTAB method. Samples were genotyped using 12 SSR markers. PCR products were separated in 8 % denaturing polyacrylamide gel or by capillary electrophoresis in a genetic analyzer. The main indicators of genetic diversity for all collections did not differ significantly from each other, and were moderate and increased in the collections of VNIIMK: AES – DES – CEB -the joint collection. In total there have been identified 37 alleles, an average 3.083 alleles per locus. The effective number of alleles ranged from 1.094 to 3.290 with an average value of 2.154. The values of the polymorphic information content (PIC) index ranged from 0.084 to 0.651, with an average of 0.434. The values of observed and expected heterozygosity ranged from zero to 0.071, 0.030, on average, and from 0.086 to 0.696, 0.500, on average, respectively. The number of shared alleles between different collections was 23. Molecular variation analysis revealed that most of the total variance (91 %) was due to differences between lines within each collection and 3 % to differences between collections. According to the results of the cluster analysis, the maternal lines from the collections of the CEB, DES, and AES of VNIIMK were mostly grouped into a cluster or subcluster separate from the paternal ones. The obtained results indicate a moderate genetic diversity of the studied sunflower lines of the breeding of VNIIMK and the existence of small differences between the collections.

ABSTRACT The objective was to evaluate the quality of sunflower seeds classified according to their thickness and passed through the seeder-fertilizer dosing system under variation of the travel speed. A lot of M734 was classified by thickness passing the seeds through a set of oblong-hole sieves and two thicknesses were selected. A portion of the seeds with only the commercial classification was also reserved, named as non-classified. The biometric evaluation was done and the sowing was carried out at 5.0, 6.5, 8.0, 9.5 and 11.0 km h-1. The quality of the seeds was evaluated through: germination and first germination count, average time and percentage of emergence in sand, accelerated aging and tetrazolium test. The classification by thickness reduce the coefficient of variation of the length, width, thickness, and mass but seeds classification does not affect seed vigor and viability after sowing under speed variation. In the higher studied speed, the passage of seeds through the dosing mechanism reduces germination. The vigor is affected at 6.5 km h-1 speed by the accelerated aging test. According to the emergence in sand and tetrazolium test, speed variation does not affect the vigor and viability of sunflower seeds.

The paper presents the results of testing of seed germination and initial growth of seedlings of four sunflower hybrids: 2950, 2951, 3007, 3009) at different temperatures: 20° C, 25°C, 30°C. In all hybrids tested, the highest germination of sunflower seeds was achieved at a temperature of 30° C; however, in two tested hybrids (2950 and 3007) no significant difference (p ≥ 0.05) was found between germination at a temperature of 30° C and 25° C. Correlation interdependence between germination and stem growth was positive and statistically significant (r=0.576p ≤ 0.05), while a positive but not statistically significant interdependence was also determined between germination and radicle growth (r=0.252p ≥ 0.05).

Sunflower (Helianthus annuus L.) is an important cash crop in Pakistan, largely cultivated for its oil. However, its production is severely affected by a soil-borne fungal pathogen, Macrophomina phaseolina causing charcoal rot. The present study investigates the effectiveness of Trichoderma species, known antagonists to soil-borne pathogens for managing charcoal rot. The research also extends to the use of biologically synthesized silver nanoparticles (AgNPs) from Trichoderma viride for disease control. Isolates of both pathogen and antagonist from the Fungal Culture Bank of Pakistan were brought and cultured on PDA media, and their in vitro interactions with M. phaseolina were observed. Additionally, the in vivo efficacy of these species was tested on sunflower plants. Results showed that three Trichoderma spp. (T. asperellum, T. harzianum and T. viride) significantly reduced the prevalence of M. phaseolina and boosted plant growth. Moreover, AgNPs synthesized from T. viride were effective in halting the progression of charcoal rot, showing an increase in biochemical markers like Chlorophyll, Carotenoids, Phenol, and Flavonoids. This study demonstrates the potential of Trichoderma spp. and AgNPs in the sustainable management of charcoal rot in sunflower, thus contributing to improved crop yields. [ABSTRACT FROM AUTHOR]

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Cultivated sunflower (Helianthus annuus L.) pollen helps attract wild and managed bees needed to produce hybrid seed. Pollen quantity and grain size (≈quality) are affected by the environment, but are also heritable traits of interest for breeding. Florets from public inbred B-lines (maintainer) and R-lines (restorer) were used to evaluate pollen quantity and quality, test for trait correlations and determine if line development has changed pollen traits. Pollen quantity (≈25,000–67,000 grains per floret) and diameter (≈30–37 μm) were similar to previous reports and values of each parameter were correlated across years. Pollen quantity per floret was positively correlated with floret size (area; mm2) but floret sizes and pollen quantity were unrelated to pollen grain size. Groups of lines released relatively early (1968–1986) or late (1988–2006) did not differ in pollen quantity or size, and male (R-line) parents did not produce larger grains. The strong, positive correlation between floret size and pollen quantity reveals a possible trade-off because wild bees generally prefer sunflowers with shallower florets. The apparent lack of change in pollen quantity or pollen grain size over time (and lack of increased pollen size in R-lines relative to B-lines) suggests that the quantity and quality of pollen may not be limiting factors in the success of inbred lines or resulting hybrids. Though sunflower lines with larger florets contain more pollen, additional variation in pollen visible on sunflower heads may relate to the timing or completeness of pollen extrusion from anther tubes. [ABSTRACT FROM AUTHOR]

The presence of weeds in the sunflower crop is one of the main factors linked to the low increase in productivity of this crop, and to determine the most appropriate management of weeds, it is essential to carry out a diagnosis through the phytosociological survey. The objective of this study was to assess the influence of chemical control on the phytosociological community of weeds in three areas cultivated with sunflower in the Parecis region (Brazil). The areas were treated with 2,4-D + glyphosate for desiccation; S-metolachlor was used for pre-emergence control in the three areas; meanwhile, sulfentrazone and flumioxazin were applied only in one area; and, finally, clethodim was applied for post-emergence weed management. Sampling was carried out at two different times, in the initial and pre-harvest stages (at 35 and 100 days after the emergence of the crop, respectively), using a quadrate, in which weeds were identified and quantified to determine the frequency, relative frequency, density, relative density, abundance, relative abundance, importance index, and similarity index between areas and times. Seventeen weed species were found in the sunflower crop (70.6% dicot and 29.4% monocotyledonous) in the two seasons, grouped into nine botanical families, with Poaceae being the most diverse family. The dicots Tridax procumbens and Acanthospermum hispidium were present in low frequency only in the initial stages of development of the sunflower crop. The weeds with the highest importance index values in the initial and pre-harvest stages were Euphorbia hirta (104 and 91%) and Bidens pilosa (45 and 66%, respectively), both belonging to the dicots group. These two species were present in the two evaluated periods and in the three experimental areas, demonstrating that there was a similarity index between them with values above 93%. These results of the phytosociological study may contribute to determining more efficient management strategies for weed chemical control in the sunflower crop. [ABSTRACT FROM AUTHOR]

The sunflower (Helianthus annuus L.) is an oleaginous plant that shows high suitability for cultivation in Brazil. However, the performance of the crop is influenced by factors such as weed interference, mainly because of the few selective herbicide options. Thus, the objective of this study was to evaluate weed control and selectivity of four pre-emergent herbicides applied to two sunflower cultivars in sandy and clayey soils. Two field experiments were conducted in a randomized block design with a 2 × 6 factorial scheme, two cultivars (CF 101 and M 734) and six treatments with S-metolachlor (1920 g a.i. ha−1), sulfentrazone (150 g a.i. ha−1), flumioxazin (40 g a.i. ha−1), and trifluralin (1780 g a.i. ha−1) and two controls, one with weeding and the other without weeding and without herbicide application, in soils with contrasting textures (sandy and clayey). No injury symptoms were observed in both cultivars, regardless of soil texture. The cultivar M 734 exhibited the highest values of the agronomic parameters evaluated. The treatment with flumioxazin provided control of more than 90% of the weeds in clayey soil and more than 64% in sandy soil. The yield of both cultivars was lower in the sandy soil. Thus, all herbicide treatments were selective for both cultivars tested, since they did not interfere with sunflower grain yield. [ABSTRACT FROM AUTHOR]

In the entire world, cardiovascular diseases (CVDs) are the main cause of death. For the treatment of CVDs, microbial fibrinolytic enzymes are highly regarded as novel therapeutic candidates. This study was purposed to determine the fibrinolytic protease activity produced by fungus source, which is Rhizopus microsporus var. oligosporus FNCC 6010 in fermented sunflower (Helianthus annuus) seed and common bean (Phaseolus vulgaris) seed. Fermentation was carried out by solid-state fermentation method at an initial pH of 5, incubation temperature of 33±1°C, and incubation time of 24 hours. The fermented seed was extracted to obtain supernatant as the crude enzyme. The proteolytic activity assay was done by the skimmed milk agar (SMA) plate method to obtain the proteolytic index, and the fibrinolytic activity assay was conducted by the fibrin-agarose plate method to get the fibrinolytic index. The results show that crude enzymes from fermented H. annuus and P. vulgaris seeds by R. microsporus have fibrinolytic protease activity with proteolytic index 2.64 ± 0.01 and 2.23 ± 0.04, respectively. The fibrinolytic index is 2.40 ± 0.06 and 1.64 ± 0.06, respectively. Therefore, the crude enzyme has the potential to be further researched as a candidate for thrombolytic agents. The purification, characterization, and in-depth research are needed to develop enzymes into preparations for preventing and treating CVDs.

This work is devoted to the elaboration of herbicides composition that would provide effective protection of sunflower (Helianthus annuus L.) crops from weeds, as well as it would be an effective means of preventing emergence of herbicide-resistant weed biotypes. For this purpose, the interaction effects, weed control efficiency, and crop selectivity had been studied in greenhouse experiment and field trial with tank mixtures of herbicide inhibitor of carotenoid synthesis aclonifen and herbicide inhibitor of electron transport in the photosystem 2 of chloroplasts prometryn. The herbicides aclonifen and prometryn were applied at different application rates separately and in the mixtures to the soil before the emergence of plant seedlings. It has been shown that in the mixtures of herbicides aclonifen and prometryn the interaction is mainly additive. The mixture of herbicides is selective for sunflower in the range of application rates of aclonifen 1.8–2.4 kg ha-1 and of prometryn 1–1.5 kg ha-1. High efficiency of weed control by the mixture was achieved with the aclonifen and prometryn application rates, respectively, 1.8 and 1.5 kg ha-1, or 2.4 and 1.0 kg ha-1. The effectiveness of weed control in field conditions with mixtures of herbicides aclonifen and promethrin at the specified rate ratio, was not inferior to the complex herbicide Primekstra TZ Gold at the recommended application rate of 4.5 L ha-1. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effect of copper soil contamination on the trace element content of sunflower aerial parts and in roots. Another aim was to assess whether the introduction of selected neutralizing substances (molecular sieve, halloysite, sepiolite and expanded clay) into the soil could reduce the impact of copper on the chemical composition of sunflower plants. Copper soil contamination with 150 mg Cu2+ kg−1 of soil and 10 g of each adsorbent per kg of soil were used. Soil contamination with copper caused a significant increase in the content of this element in the aerial parts (by 37%) and roots (by 144%) of sunflower. Enriching the soil with the mineral substances reduced the amount of copper in the aerial parts of sunflower. Halloysite had the greatest effect (35%), while expanded clay had the smallest effect (10%). An opposite relationship was found in the roots of this plant. In copper-contaminated objects, a decrease in the content of cadmium and iron and an increase in the concentrations of nickel, lead and cobalt in the aerial parts and roots of sunflower were observed. The applied materials reduced the content of the remaining trace elements more strongly in the aerial organs than in the roots of sunflower. Molecular sieve had the greatest reducing effect on the content of trace elements in sunflower aerial organs, followed by sepiolite, while expanded clay had the least impact. The molecular sieve also reduced the content of iron, nickel, cadmium, chromium, zinc and, especially, manganese, whereas sepiolite reduced the content of zinc, iron, cobalt, manganese and chromium in sunflower aerial parts. Molecular sieve contributed to a slight increase in the content of cobalt, while sepiolite had the same effect on the content of nickel, lead and cadmium in the aerial parts of sunflower. All materials decreased the content of chromium in sunflower roots, molecular sieve—zinc, halloysite—manganese, and sepiolite—manganese and nickel. The materials used in the experiment, especially the molecular sieve and to a lesser extent sepiolite, can be used effectively to reduce the content of copper and some other trace elements, particularly in the aerial parts of sunflower. [ABSTRACT FROM AUTHOR]

As plant breeding is a very complex and sophisticated process, it is of paramount importance to understand the nature and magnitude of interdependence between specific plant features. Using PCA and correlation analysis, this study examined the variability in features of two types of inbred sunflower lines and determined its connection with their seed yields. The experiment was conducted as a randomized complete block design with four replications in Rimski Šančevi (the experimental field of the Institute of Field and Vegetable Crops in Novi Sad) in 2018 and 2019. It examined a total of nine inbred sunflower lines created at the Institute of Field and Vegetable Crops in Novi Sad. The results obtained suggest a high degree of variability in the examined traits of inbred sunflower lines considered, whereas the significance indicated by the F test was confirmed by the Duncan test performed. A high degree of variability was also found between the different types of inbred lines considered. A positive correlation was found between all four traits observed in the inbred sunflower lines considered, with different levels of significance. A statistically significant positive increase in the head diameter was followed by an increase in the weight of 1000 seeds, which generated a higher seed yield per unit area. According to the arrangement of different types of inbred lines considered on the PCA biplot, it can be concluded that the linoleic inbred lines G7L and G8L had the highest average values of the 1000-seed weight, head diameter and seed yield throughout the course of both experimental years. The useful data obtained by PCA analysis can facilitate successful selection programs aimed at developing sunflower genotypes that possess high stability and seed yields.

The temperature of the nutrient solution is one of the main obstacles of hydroponic production in hot climates and can affect the nutrient absorption of plants. Additionally, the hydroponic cultivation of cut flowers is rarely done, and hence, there is a lack of studies on this topic. The objective of this experiment was to determine the ideal temperature of the nutrient solution as well as the influence of the plant density factor for hydroponic cultivation in NFT (Nutrient Film Technique) of the cultivar Girassol de Jardim Amarelo Alto, ISLA®. The experiment was installed in a greenhouse, with 50% shading. The experiment adopted a completely randomized design in a factorial scheme with plots subdivided in space, with the main plots composed of two densities (15 and 30 plants m-2) and the subplots of four temperatures of the nutrient solution (20, 25, 30 °C and uncontrolled temperature) with three replications each. The variables analyzed were plant height, stem diameter, internal and external diameter of the flower, number of leaves, number of buds and flowers, dry and fresh root mass, dry and fresh shoot mass, and cultivation cycle. The data were submitted to an analysis of variance using the statistical software SISVAR. The density of 15 plants m-2 proved to be more efficient, presenting plants of commercialization standard. Cooling the nutrient solution did not improve the production and quality of sunflower flowers.

Potassium (K) participates in critical processes in sunflower cultivation, such as osmotic regulation and translocation of photosynthesis. However, the absorption or accumulation of this nutrient occurs differently owing to edaphoclimatic factors or between cultivars. The objective of this study was to evaluate the nutritional efficiency of sunflower cultivars as a function of different dosage K dosages in a semiarid region. To this end, two experiments were conducted in 2016 and 2017. The treatments consisted of five dosages of K at 0, 30, 60, 90, and 120 kg ha-1 K2O and four sunflower cultivars, Aguará 6, Altis 99, Multissol, and BRS 122. The experimental design was a randomized block with four replications and subdivided plots. The characteristics evaluated were agronomic efficiency, physiological efficiency, recovery efficiency, utilization efficiency, and accumulation of total K in the plant. Sunflower cultivars responded to K dosages in the two crops, with variations in efficiency parameters. Crop 2 showed better nutritional efficiency compared to crop 1. Aguará 6 showed greater nutritional efficiency than the other two crops. The use of dosages between 75 and 91 kg ha-1 of K2O provided better efficiency in K usage for the cultivars.