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Silicon (Si) has been extensively studied for its ability to decrease sodium (NaCl) toxicity in various plant species. Nonetheless, the processes that drive these responses are still not well understood. In this study, we investigate the effects of silicon (Si) on the modification of hydrogen peroxide concentration [H2O2], photosynthetic pigment content, nutrient accumulation, and the production of root and shoot dry biomass in sunflower (Helianthus annuus L.) plants hydroponically grown with NaCl (0 and 100 mM) in combination with Si (0 and 2.0 mM). Salt stress induced a significant decrease in plant growth due to high [H2O2] and a decrease in photosynthetic pigment content and nutritional status, denoting that there is oxidative and ionic stress. Nevertheless, Si addition to the growth medium consistently decreased the [H2O2] in sunflower and photosynthetic pigment content, and macro- and micronutrient accumulation, which was associated with an increase in root and shoot dry matter production. These findings indicate that adding Si to the growth medium is crucial for enhancing plant resistance to salt-induced ionic and osmotic stress, making it a promising strategy for improving crop growth and management under salinity conditions. [ABSTRACT FROM AUTHOR]

In rain-fed crop, after the first monsoon rain, the farmers plow their lands and sow seeds. Because of the lack of moisture in the soil, sown seeds fail to germinate and are eventually destroyed. As a result, the farmers suffer economic losses. To address this issue, seed encapsulation with seaweed powder was performed. Micro (Spirulina plantensis and Chlorella vulgaris) and macroalgae (Sargassum, Halimeda macrolaba, and Gracilaria) were collected from the southeast coast of India. The seaweeds were dried, powdered, and weighed about 1 g of each and were filled in a gelatin capsule. Soil profile (pH, EC, water percolation rate, moisture content, water holding capacity, capillary action, N, P, K, Zn, Fe, Cu, and Mn) was characterized before cropping. Abelmoschus esculentus, Raphanus sativus, Helianthus annuus, and Capsicum annum cultivation were done. The plant growth and yield were analyzed. The texture was clay loamy soil with micro and macronutrients present in it. In Abelmoschus esculentus, the number of leaves, plant height, and branches were increased as compared to control. Sargassum treatment shows highest yield (285.6 g) of A. esculentus. The nutritional quality was enriched in Sargassum treatment followed by C. vulgaris and S. platensis. In Raphanussativus L. cultivation, the estimated yield is as follows: in Sargassum (5.95 kg), C. vulgaris (5.10 kg), S. platensis (3.95 kg), and control (3.15 kg). The yield of Helianthus annuus L. cultivation showed increased in Sargassum treatment of about 200.5-g total seed weight. The yield was higher in Sargassum treatment as compared to C. vulgaris and Gracilaria in Capsicum annum cultivation. Sown seeds in novel seed encapsulation remain undamaged in soil until favorable rainfall occurs. Another benefit is that a marine source biofertilizer enriched with macro/micronutrients and hormones was encapsulated around the seeds, promoting plant growth and yield. The application of fertilizer to a large area is both costly and time consuming. In contrast, applying to specific roots around the plant is both effective and cost effective in terms of plant growth. This novel seed encapsulation with marine source biofertilizer has two advantages: (i) it protects the seed from damage and (ii) it supplements plant nutrition. As a result, farmers lose less and profit more by using less biofertilizer. (a) Powder of micro and macroalgae. (b) Seeds. (c) Encapsulation of seed with micro and macroalgae powder. (d) Encapsulated with macroalgae. (e) Encapsulated with microalgae. (f) Encapsulated with micro and macroalgae. (g) Dissolving of gelatin in soil. (h) Experimental field. (i) Capsule placing inside the soil. (j) Capsule in soil. (k) Seed germination. (l) Plant growth. (m) Ladies finger yield. (n) Sunflower yield. (o) Radish yield [ABSTRACT FROM AUTHOR]

Interspecific hybrid materials obtained from crosses between cultivated sunflower and some accessions of wild species of the genus Helianthus were studied. Samples of the annual wild species Helianthus annuus (w.f.), H. argophyllus and the perennial hexaploid species H.resinosus were used as paternal parents. In the crosses, five CMS lines, developed at DАI-General Toshevo, were used as the maternal parents. The embryo rescue method was applied to obtain hybrid seeds from the cross 830A x GT-M-046 (H. resinosus Small (2n=102). By applying the hybridization scheme “cultivated sunflower x wild species”, a sufficient amount of seeds were obtained for further morphological, phenological, biochemical and phytopathological studies of the hybrid progenies. The content of oil and oleic acid in the seeds was determined. Interspecific forms characterized with highest content of oil and oleic acid in the seeds were obtained from crosses 4499A x GT-E- 166, 4499A x GT-E-122, 830A x GT-E- 171, 4499A x GT-E-153, 3607A x GT-E- 046, 217A x GT-E-122 and 217A x GT-E- 126. The obtained hybrid materials can be successfully used as an initial breeding material to enrich the genetic plasma of cultivated sunflower and create high oleic lines and hybrids. [ABSTRACT FROM AUTHOR]

Drought is characterised as a recurring climatic phenomenon with prolonged duration, affecting land through below-average rainfall and often accompanied by high temperatures. When the available water falls below the optimum level, water deficit or water stress arises, disrupting normal plant processes. This condition poses challenges for plant growth and development as it hampers the internal water transport, induces stomatal closure, and limits access to photosynthetic resources. The study employed the annual sunflower as the experimental plant. The plants were cultivated in a controlled environment with a temperature ranging from 20 to 25°C and a humidity level of 55 to 60%, supplemented by MARS HYDRO artificial LED lighting set to a 12-h photoperiod. Radial changes in the plant stems were monitored using a DD-S type dendrometric sensor to measure radial fluctuations. The collected data were recorded in a dendrometric data logger DL 18. Data collection occurred at hourly intervals from February 20 to March 9, 2023. The nine plants were divided into three groups, each comprising three plants. All plants from groups 1 and 2 received irrigation at one- day intervals (group 1 – 80 cm 3 per plant, group 2 – 40 cm 3 per plant) and group 3 was not irrigated. Based on these findings, visible water stress was evident in the plants under experimental conditions. Consequently, continuous monitoring throughout the growing season will be essential to adjust the irrigation rate to meet the requirements of the plants.

Eight Jersey cows (2nd-4th lactation; 483 ± 43 kg body weight; milk yield 21±2.2 kg day-1) were used in a double 4x4 latin square design to evaluate whether the inclusion of increasing levels of sunflower oil in the concentrate up to the limit of 110.0 g kg-1 DM of EE, in replacement to corn grain, has an impact on milk production and composition, feed efficiency, energy balance, intake and digestibility. of diets, and the fatty acid profile of milk fat from Jersey cows. The treatments consisted in lipid supplementation with increasing levels of sunflower oil replacing the corn grain and wheat bran of concentrate, including: CD (control diet), without sunflower oil and with 38 g kg-1 of EE dry matter (DM); and three treatmens with sunflower oil concentrate-included: SF65= 65 g kg-1 DM of EE; SF86=86 g kg-1 DM of EE and SF110=110 g kg-1 DM of EE. The increase of EE in diets did not affect the dry matter intake, neutral detergent fiber or crude protein. There was a linear increase in the digestibility coefficients for organic matter, crude protein, EE, neutral detergent fiber and blood levels of cholesterol. Treatments did not affect milk production, fat content, lactose or total solids. It is possible to use up to a limit of 110.0 g kg-1 DM of EE in the diet, decreasing the concentrate total amount.

Drought is characterised as a recurring climatic phenomenon with prolonged duration, affecting land through below-average rainfall and often accompanied by high temperatures. When the available water falls below the optimum level, water deficit or water stress arises, disrupting normal plant processes. This condition poses challenges for plant growth and development as it hampers the internal water transport, induces stomatal closure, and limits access to photosynthetic resources. The study employed the annual sunflower as the experimental plant. The plants were cultivated in a controlled environment with a temperature ranging from 20 to 25°C and a humidity level of 55 to 60%, supplemented by MARS HYDRO artificial LED lighting set to a 12-h photoperiod. Radial changes in the plant stems were monitored using a DD-S type dendrometric sensor to measure radial fluctuations. The collected data were recorded in a dendrometric data logger DL 18. Data collection occurred at hourly intervals from February 20 to March 9, 2023. The nine plants were divided into three groups, each comprising three plants. All plants from groups 1 and 2 received irrigation at oneday intervals (group 1 - 80 cm³ per plant, group 2 - 40 cm³ per plant) and group 3 was not irrigated. Based on these findings, visible water stress was evident in the plants under experimental conditions. Consequently, continuous monitoring throughout the growing season will be essential to adjust the irrigation rate to meet the requirements of the plants. [ABSTRACT FROM AUTHOR]

The piling up of fly ash (FA) from thermal power plants ends up degrading land and water sources and the problem has even fester with time. An energy plantation on fly ash amended soil appears to be the most attractive integrated approach towards better waste utilization and sustainable remediation. Recently the research is focused to figure out the best remediation plant alternative among the energy crops. In the present study a comparative assessment of growth, remediation and yield of energy plant viz. Jatropha curcas, Millettia pinnata, and Helianthus annus were made with the fly ash amended soil with 0, 10, and 15% of FA treatments. It includes morphological growth measurements, estimation of remediation efficiency (RE), bio-concentration factor (BCF), and energy yields. The research outcome confers J. Curcas to possess better response altogether in comparison to M. pinnata and H. annus. The plant obtained greater absolute growth rate (AGR), leaf area (LA) as morphological assessment parameters, and greater yield in terms of biomass and energy. Although, H. Annus absorbed maximum metal content but was insusceptible to survive the experimental duration with lesser RE. J. Curcas obtained maximum RE for 10% FA treatment and outcomes to be the potential alternative among the three energy plants. The remediation efficiency of J. curcas for Al, Fe, Mn, and Zn was 187.79%, 150.36%, 118.67%, and 137.43% greater than the control. Based on Principal Component Analysis (PCA) J. curcas at F10 treatment has better association of growth, remediation, and yield parameter values among other plant alternatives. [ABSTRACT FROM AUTHOR]

Current industrial developments, advanced farming techniques, and further anthropogenic activities are adding substantial amounts of heavy metals into the ecosystem and having dangerous effects on lifeforms, including plants and animals, and changing their biological activities. Decontamination following the heavy metal contamination is an important point deserving attention in the current scenario. Among all the other approaches used for this purpose, bioremediation is ecofriendly and green approach that can be used to remediate heavy metal toxicity. In plant cells, the regulation of ionic homeostasis is a primary physiological prerequisite for upholding plant development, growth, and production. To avoid the dreadful effects of toxic heavy metal exposure, plants manifest physiological, biochemical, and structural responses. In the present research, we reported on the isolation and molecular identification of an effective heavy-metal-tolerant bacterial strain, Staphylococcus lentus (E3), having a minimum inhibitory concentration of 300 µg/mL for chromium, Cr, taken from soil polluted with industrial effluents at Kasur, Pakistan. Bacterial inoculations enhanced all the growth parameters of Triticum aestivum and Helianthus annus. To observe the physiological strain, the proline content and peroxidase (POD) activities were estimated under Cr stress in the bacterial-inoculated plants. The chlorophyll content and Cr uptake in the aerial parts the of plants were also studied, along with the overexpression of proteins. The bacterial inoculations produced encouraging results. Bioremediation using PGPR is an efficient, convincing, and reliable approach to attenuating heavy metal toxicity. [ABSTRACT FROM AUTHOR]

The postharvest quality and longevity of cut flowers is influenced by several factors, with the development stage being one of the determining aspects. The determination of the harvest point is variable and must be carried out depending on the physiology of flower development and the proximity of the consumer market. In this sense, the objective was to determine the harvesting point and the ideal stem length for harvesting 'Sol Vermelho' ornamental sunflower. The experimental design adopted was completely randomized, arranged in a 2 x 4 factorial scheme (harvest point x stem length), where stems harvested at stages R4 and R5.5 and in four lengths of 50, 60, 70, and 80 cm were used. The results demonstrate that the early harvest (R4 stage) of the ornamental sunflower flower 'Sol Vermelho' stems is a viable alternative that allows greater post-harvest durability and, consequently, the commercialization of the stems for a longer period of time. In addition, stems harvested at stage R5.5 (open flowers) with lengths of 50 and 60 cm can be recommended for sale in regions close to the production sites. [ABSTRACT FROM AUTHOR]

Irrigation is used as a management strategy in many regions around the world. However, due to the salinity characteristics of the semiarid region, this measure has become increasingly difficult due to the scarcity of good quality water with low levels of salts. One of the factors that can lead to salt stress are crops irrigated with water with high electrical conductivity, reflecting in a soil unfavorable to plant growth. Sunflower is a drought and salinity tolerant crop. In this context, the objective of this work was to evaluate the use of organic residue from marine macroalgae on the production of sunflower plants under two saline conditions (50 or 100 mM NaCl) and control group in substrates containing organic compound from algae or earthworm humus. The use of algae compost was more efficient than earthworm compost under control conditions. Under 50 mM salinity conditions, the results were similar to the use of humus. The use of this residue can be an alternative to commercial fertilizers under controlled conditions or with moderate salinity, minimizing production costs. [ABSTRACT FROM AUTHOR]

Present study was performed at Department of Soil and Environmental Sciences, University of Sargodha in 2017 to evaluate the efficiency of various commercially available domestic and imported DAP for growth of sunflower. In this experiment six treatments were used; T1 : Control, T2 : P from conventional DAP, T3 : P from Impregnated DAP, T4 : P from Reduced DAP, T5 : P from Hifa DAP and T6 : P from environmentally smart DAP (polymer coated DAP). The duration of experiment was up to maturity of crop. After the completion of experiment different yield contributing parameter were recorded and analyzed by standard statistical procedures. It was concluded that smart fertilizers were the better source of plant nutrients for better growth and nourishment of sunflower. Applications of all types of DAP performed better in improving sunflower performance in comparison to conventional DAP. However, environmentally smart polymer coated DAP fertilizer performed better for improving plant height (22.25 cm), stem diameter (0.97 cm), head diameter (7.28 cm), fresh weight (35.88 g) and achene diameter (2.79 cm) of sunflower as well as available P concentration (10.92 ppm). In short, environmentally smart polymer coated DAP fertilizer (T6) could be helpful to get maximum sunflower yield. [ABSTRACT FROM AUTHOR]

ABSTRACT The maintenance of seed viability is widely studied since preserving the physiological characteristics that will allow efficient germination and adequate field occupation is broadly pursued. However, even under optimal storage conditions, the aging process is inherent to the seed’s life. In order to understand the effects of storage under low and normal oxygen conditions, this work sought to evaluate the physiological responses of two seed lots of two sunflower hybrids stored under different oxygen availability (normoxia and hypoxia) over a 360-day period. Aiming to investigate the effects of storage, the activities of the enzymatic antioxidant metabolism, hydrogen peroxide and MDA content, and the performance of viability, and vigor tests (tetrazolium test and electrolyte leakage) were performed with the stored seeds every 60 days. The hypoxia conditions were not able to keep seed viability over time, probably affecting negatively the embryonic axis. Throughout the evaluations, the viability tests demonstrated that the storage in the two experimental conditions was not able to contain the aging of the seeds. The increased content of H2O2 and MDA, associated with the enhanced electrical conductivity over time, indicate that there were losses by lipid peroxidation and that the aging process was not contained by storage under low oxygen availability.

Insights into plant endosphere bacterial diversity and exploration of their bioincentives in the formulation of biofertilizers promise to avert ecological disturbances. Here, we presented the sequence dataset of the endophytic bacterial community from the roots and stems of sunflower obtained from farmlands in Itsoseng and Lichtenburg, North West Province of South Africa, using 16S rRNA gene amplicon sequencing. The climatic conditions of this region are characterized by an annual rainfall of about 600 mm and a temperature range of 3 to 21°C during winter and 22 to 34°C during summer. The genomic DNA was obtained from 1 g of each macerated sample using commercial DNA kits (DNeasy® Plant Mini kit, Qiagen, USA). The DNA was amplified through polymerase chain reaction at the V4 region using the specific forward and reverse primers. Amplicon sequencing was performed on the Miseq Illumina platform. Sequence read processing was performed using QIIME 1 16S-based pipeline implemented on Nephele microbial bioinformatics platform using default parameters. The sequence has been deposited in the Sequence Read Archive (SRA) of the National Center for Biotechnology Information (NCBI) with assigned Bioproject accession numbers. The data reveals the endophytic bacterial community structure and functions in sunflower cultivated in organic and nonorganic soils at growing and flowering stages.

Contract farming is a form of vertical coordination, largely aimed at correcting market failures associated with spot markets that arise due to imperfect information. The objective of this study was to assess the determinants of farmer engagement in sunflower (Helianthus annus L.) contracts in northern Uganda. Stratified random sampling was used to select 150 contracted and 150 non-contracted sunflower farmers in Oyam District, from where primary data were collected using a semi-structured questionnaire. A Logistic regression model was used to examine the factors that influenced farmer participation in contract farming. The major determinants of participation in contract farming by smallholder farmers were age (P<0.1), sunflower production experience (P<0.01), access to credit (P<0.01) and unit produce price (P<0.01).Collaborative efforts by all parties engaged in contracting arrangements are necessary to negotiate a minimum price with the farmers, with a possibility to renegotiate whenever the market price is above the set price. The study pointed out that improvement in rural roads to enhance transportation of produce to mini-store is vital in driving sunflower contract farming in Oyam district. Therefore, policies aimed at improving rural roads are urgently needed. [ABSTRACT FROM AUTHOR]

This work aimed to evaluate the efficiency of boron and calcium rates, via leaf application, on sunflower grain yield and morphologic plant parameters. The experiment was carried at Federal University of Technology – Paraná, Campus Dois Vizinhos, PR, Brazil, during the period of September, 2008 to Abril, 2009. The soil of experimental area is an Oxisol. The experimental design was as completely randomized blocks, with four replicates. Plots were composed of six meters long and five seed lines of 0.9 meters spaced. The genotype used was Agrobel - La Tijereta. Treatments were: (i) Witness; (ii) 2000 g of B ha-1 via soil; (iii) 250 g of Ca ha-1 in leaves; (iv) 500 g of Ca ha-1 in leaves; (v) 750 g of Ca ha-1 in leaves; (vi) 1000 g of Ca ha-1 in leaves; (vii) 250 g of B ha-1 in leaves; (viii) 500 g of B ha-1 in leaves; (ix) 750 g of B ha-1 in leaves; and (x) 1000 g of B ha-1 in leaves. Soil and leaves treatment with boron were made with Sodium Octaborate. Calcium treatments were made with Calcium Chloride. It was analyzed: number of achenes per plot, plant stature, number of green leaves, achene’s diameter, mass of one hundred grains and grain yield. No answer to calcium and boron leaf application was observed on the present study, probably as consequence of low soil water availability during sunflower growth season, what resulted on low mean sunflower grain yield and compromised plant morphological parameters.

Sunflower is a species that is sensitive to local climate conditions. However, studies that use artificial neural networks (ANNs) to evaluate this influence and create tools such as agricultural zoning of climate risk (ZARC) have not been conducted for this species. Due to the importance of sunflower as a human food source and for biodiesel production, and also the necessity of conducting research to evaluate the suitability of this oleaginous species under different climatic conditions. Thus, we seek to construct a ZARC for sunflower in Brazil simulating sowing on different dates and using meteorological elements spatialized by ANNs. Climate data were used: air temperature (T), rainfall (P), relative air humidity (UR), solar radiation (MJ_m−2_d−1) and wind velocity (U2). Climatic regions considered suitable for the cultivation of sunflower had average annual values for T between 20 and 28°C, P between 500 and 1.500 mm per cycle, and soil water deficit (DEF) below 140 mm per cycle. A neural network is an efficient tool that can be used in spatialization of climate variables quickly and accurately. Sunflower sowing in the spring and summer are the ones that provide the largest suitable areas in southeastern Brazil, with 58.13 and 64.36% of suitable areas, respectively. [ABSTRACT FROM AUTHOR]

Drought is one of the most important abiotic stresses that affects plant growth and development. Polyamines (PAs) can have an active key role in improving plants tolerance to various stresses. Based on global ecological conditions, plants growing in about one third of the potentially viable lands such as Iran are exposed to drought stress during growing season. The objective of the present study was to investigate the enhancing effects of foliar application of Putrescine (PUT) on short-term tolerance against water stress in ornamental sunflowers. This study was conducted in the experimental greenhouse of the Department of Horticultural Sciences and Landscape, Ferdowsi University of Mashhad, Iran. Plant materials used in this study were the F1 seeds of ornamental sunflower (Helianthus annus L. cv. Sunbright kids). The experiment was conducted as a factorial (2 x 3) in complete randomized block design with four replications and 8 plants in each replicate. Plants were irrigated at 40 and 80% field capacity (FC). Foliar spray of PUT (0, 75 and 150 mg l-1) was applied twice during plants growing period. Water stress at 40% FC as compared with 80% FC, significantly affected reproductive and vegetative characteristics of plants. The effects of exogenous application of PUT (75 and 150 mg l-1) in comparison with control, significantly increased leaves number per plant, leaves fresh and dry weight, leaves area, stems fresh and dry weight, stems diameters at soil surface, plants height, roots fresh and dry weight, roots area, number of flowers, flowers longevity, seeds number per head and seeds weight. In this study, there was no significant difference between the effects of PUT levels on most of the reproductive and vegetative characteristics of sunflower plants under water stress conditions. The results confirmed that foliar application of PUT protected plants against drought stress and increased specially flowers retention. Therefore, to improve parameters of the studied plants under drought stress, the commercial application of PUT (75 mg l-1) is recommended for this cultivar. [ABSTRACT FROM AUTHOR]

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Sunflower (Helianthus annus L.) is one of the important oil seed crop in India, contributing to the edible oil industry of the country. In India it is cultivated in an area of 14 lakh ha with a production of 8.23 lakh tones. The field screening was carried out at Sambavar vadakarai and Udappankulam villages of Tirunelveli district of Tamilnadu during January to April and June to September, 2016 in two seasons to evaluate the resistance of one hundred and twelve accessions of sunflower against head borer (Helicoverpa armigera Hubner) under field conditions. Observations were made on the number of larvae/head at weekly interval starting from 55th day of sowing till harvest. During both seasons, four varieties KBSH 1, IHT 751, GHU 631 and GMU 615 recorded the least mean larval population. In the first season, the population ranged from 0.39 to 4.99 larva/plant whereas in the second season, it ranged between 0.35 and 2.78 larva per plant and a significant difference in the population was noticed. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annus L.) is one of the important oil seed crop in India, contributing to the edible oil industry of the country. In India it is cultivated in an area of 14 lakh ha with a production of 8.23 lakh tones. The field screening was carried out at Sambavar vadakarai and Udappankulam villages of Tirunelveli district of Tamilnadu during January to April and June to September, 2016 in two seasons to evaluate the resistance of one hundred and twelve accessions of sunflower against head borer (Helicoverpa armigera Hubner) under field conditions. Observations were made on the number of larvae/head at weekly interval starting from 55th day of sowing till harvest. During both seasons, four varieties KBSH 1, IHT 751, GHU 631 and GMU 615 recorded the least mean larval population. In the first season, the population ranged from 0.39 to 4.99 larva/plant whereas in the second season, it ranged between 0.35 and 2.78 larva per plant and a significant difference in the population was noticed. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • SFE and ESE technique were used to extract bioactive compounds from H. annuus leaves. • Fractionation of extracts using three separators was evaluated for both techniques. • High overall yields were obtained with ESE and adding water to the solvent system. • Fraction S3 using CO 2 +50% H 2 O was rich in potential allelopathic compounds. • 2 sesquiterpenes, 1 flavonoid and 1 lignan presented high inhibitory activity profiles. Abstract The allelopathic potential of Helianthus annuus L. leaves was study based on bio-directed chemical fractionation approach. Aerial parts of H. annuus were extracted by means of SFE using supercritical carbon dioxide (scCO 2) and ESE using CO 2 +50% EtOH/H 2 O (varying ethanol in water from 0 to 100%). Extractions were carried out at 400 bar, 55 °C, 20 g/min and for 4 h. Then, extracts were fractionated in three separators at the following conditions: S1: 200 bar/45 °C; S2: 90 bar/40 °C; and S3: 1 atm/30 °C. ESE obtained higher overall yields than scCO 2 and the use of water as cosolvent (CO 2 +50% H 2 O) resulted in a S3 fraction free from chlorophylls and rich in bioactive compounds. 14 compounds, including fatty acids, terpenes, flavonoids and heliannuols, were isolated from this fraction. After performing the bioassay on pure compounds, heliannuol D, tambulin, pinoresinol and sesquiterpene 10-oxo-isodauc-3-en-15-al showed the most effective inhibitor profiles. [ABSTRACT FROM AUTHOR]

Vanadium (V) is the 21st most abundant element in the Earth's crust. If some doubt exists about the role of vanadium as a beneficial element, there is no doubt that at high levels it is dangerous to plants. In this study the effect of different concentration of V (0, 3.25, 7.5 and 15 mg L-1) was investigated hydroponically in a complete randomized design on sunflower plant. The results indicated that V at all applied concentrations significantly decreased the plant's growth, and total protein and carotenoid contents, but increased the total chlorophyll and soluble sugars contents. Also, the obvious induction in the phenylpropanoid pathway was seen in response to V application. The highest values for PAL (Phenylalanine Ammonia Lyase) activity, and lignin, tannins and flavonoids contents were observed at concentration of 15 mg L-1 of V. While, the anthocyanin content of plants showed significant increase at concentration of 7.5 mg L-1 of V. From this study it could be concluded that the applied concentrations of V were toxic for sunflower and the plant by employing the phenylpropanoid pathway efforts to overcome this stress. [ABSTRACT FROM AUTHOR]

ABSTRACT Chemical ripeners are frequently used on sugarcane crops in order to increase profitability. However, the drift of these products to neighbouring fields can expose susceptible non-target plants, such as sunflower, to these agents causing indirect impacts on growth and development. Therefore, this study aimed to assess the toxicity characterize possible changes in the growth of sunflower plants exposed to simulated drift of the ripeners glyphosate and trinexapac-ethyl. For each ripener, the following doses were used: glyphosate (0 (control), 3.6, 7.2, 14.4, 28.8 and 86.4 g a.e ha-1) and trinexapac-ethyl (0, 3.12, 6.25, 12.50, 25 and 75 g a.i ha-1). The effects of these products on plant height, number of leaves, leaf area, stem diameter and dry matter (leaves, stem, flower, root, shoot and total) were evaluated. We also conducted a visual analysis of symptoms of phytotoxicity after exposure. The effects of the ripeners on sunflower plants varied depending on the type of agent used and the dose. Plants treated with glyphosate showed altered growth patterns, indicating high sensitivity of these plants to the herbicide. With increasing doses, glyphosate drift promoted lower growth and development of sunflower plants and negatively affected productivity. Nevertheless, trinexapac-ethyl drift, in the evaluated doses, did not affect sunflower plants.

The aim of this work is to describe the differences in sensitivity of Clearfield, ExpressSun and non-herbicide tolerant (HT) sunflower cultivars to several acetolactate synthase inhibitor herbicides and to find out the differences in sensitivity in F1 and F2 generations of these cultivars. Non-HT sunflower was very sensitive to most of the tested herbicides, except for nicosulfuron (efficacy 43-75%). F2 generation of non-HT sunflower showed a low level of sensitivity to imazamox (efficacy 10-43%) and to nicosulfuron, tribenuron, thifensulfuron and rimsulfuron under dry conditions (efficacy 43-83%). Sensitivity of Clearfield sunflower (cultivar with tolerance to imidazolinone herbicides) to tested sulfonylurea varied according to used herbicide and weather conditions. The highest efficacy on Clearfield sunflower showed iodosulfuron (97-100%) > florasulam (88-100%) > foramsulfuron (40-98%) > thifensulfuron (12-99%) > rimsulfuron (37-99%) > tribenuron (0-87%) > nicosulfuron (0-78%). ExpressSun sunflower (cultivar with tolerance to tribenuron) was the most tolerant to all tested herbicides. The lowest efficacy on F1 generation showed tribenuron (0%) > imazamox (0-17%) > nicosulfuron (0-43%) > thifensulfuron (0-57%) > rimsulfuron (0-70%) > foramsulfuron (8-75%) > florasulam (75-96%) > iodosulfuron (87-98%). Sensitivity of F2 generation of ExpressSun to tested herbicide was usually higher as compared to F1 generation.

The aim of this study is to analyze factors and mechanisms involved in dispersal and deposition of airborne pollen captured with Tauber type traps in a 20 x 20 m plot of Helianthus annus cultivation and accompanying weeds and to investigate the relation of these processes with the vegetation structure and dynamics from cultivation to its senescence over a 14 week period. Weekly samples obtained with pollen traps showed a significant change in the deposition due to a filter effect and dispersal patterns due to source variations during the time elapsed. A conceptual and interpretative model for both processes and its relation to pollen sources is proposed. Our results showed that in the study site, the leaves development of Helianthus annus produced a pollen filter effect. Furthermore the cultivation and weeds phenology was linked to deposition and dispersal of pollen, whose sources were the study plot, local or extralocal distances. Three periods could be characterized according to the presence of pollen contents coming from different pollen sources. The first period was characterized by deposition of local and extralocal pollen types such as Caryophyllaceae, t. Physalis, etc, the second by pollen originate from the study plot (such as Helianthus annus) and the third by a combination of all three sources. [ABSTRACT FROM AUTHOR]

The use of high quality seeds is one of the important factors to increase productivity in areas cultivated with sunflower. The aim of this study was to investigate the relationship between internal morphology and germination of sunflower seeds with the X-ray test and computer-aided X-ray imaging analysis with the software Tomato Analyzer®, and check whether or not this relationship changes after a period of seed storage under different environmental conditions. For this purpose, five lots of sunflower seeds from cultivar Catissol 01 were used. They were evaluated during two experimental periods: at 0 and 4 months after storage; the first evaluation was performed to characterize the lots; after that, the seeds were stored in two environments, cold and dry chamber (10 °C and 30% relative air humidity) and non-controlled environment. The seed moisture content was determined and, after that, the seeds were submitted to the X-ray and germination tests. The X-ray analysis allowed the visualization of seed internal structure as well as the study between seed morphology and germination; the greater embryo size, in general, does not provide greater potential for seed germination; regardless of the storage conditions for the four-month period, there was no reduction in the area of the embryo.

Objetivou-se, neste trabalho, avaliar a eficiência de espécies vegetais na remediação de um Argissolo Vermelho-Amarelo contaminado com sulfentrazone. O trabalho foi conduzido em duas etapas. Na primeira, avaliou-se o crescimento de Helianthus annus, Canavalia ensiformis, Dolichos lab lab e Arachis hypogaea em solo contaminado com sulfentrazone; na segunda, cultivou-se, no mesmo solo, uma espécie (sorgo) indicadora de resíduo de sulfentrazone no solo, para avaliar a capacidade remediadora dessas espécies. Na primeira etapa, foram utilizados vasos contendo 6,0 kg do substrato. Após a irrigação dos vasos, aplicou-se na superfície do solo o herbicida. Um dia após essa aplicação, procedeu-se à semeadura das espécies vegetais, as quais foram colhidas 100 dias depois e secas em estufa, determinando-se a matéria seca da parte aérea. Na segunda etapa, foram coletadas amostras de 3,0 kg de solo de cada vaso, onde foi cultivada a planta indicadora. Aos 20 e 50 dias após a emergência, foi avaliada, visualmente, a intoxicação das plantas de sorgo, sendo determinada a matéria seca da parte aérea dessas plantas aos 50 dias após a emergência e aos 50 dias após o primeiro corte. A produção de matéria seca da parte aérea de H. annus, C. ensiformis, D. lab lab e A. hypogaea não foi alterada, indicando que essas espécies foram tolerantes ao sulfentrazone; entretanto, H. annus apresentou melhor capacidade para remediação de solo contaminado com esse herbicida.The aim of this work was to evaluate the efficiency of plant species in the remediation of a red-yellow Hapludalf contaminated with sulfentrazone. The work was conducted at two stages. At the first, the growth of Helianthus annus, Canavalia ensiformis, Dolichos lab lab and Arachis hypogaea was evaluated in soil contaminated with sulfentrazone. At the second stage, a species (sorghum) indicator of residues of this herbicide was sown in the same soil. At the first stage, pots containing 6.0 kg of substrate were used. After the pots were irrigated, the herbicide was applied on the soil surface. One day after the application, the vegetal species were sown. These species were collected 100 days later and stove-dried for determination of shoot dry matter accumulation. At the second stage, soil samples of 3.0 kg were collected from each pot where the species indicator of sulfentrazone residues was cultivated. At 20 and 50 days after emergence, the intoxication of the sorghum plants was visually determined and the shoot dry matter of these plants was determined 50 days after emergence and 50 days after the first cut. The production of shoot dry matter of H. annus, C. ensiformis, D. lab lab and A. hypogaea was not affected, indicating that all species were tolerant to sulfentrazone. However, H. annus showed greater capacity for remediation of soil contaminated with this herbicide.

Considerando que o Brasil detém uma vasta gama de matérias-primas para produção de biodiesel, e também que há a possibilidade de produção em pequena escala, prima-se por estudos de cunho econômico a partir de metodologias de fácil execução. O objetivo do trabalho foi demonstrar uma metodologia e sua aplicação para avaliação dos custos inseridos dentro do processo produtivo e de utilização do biodiesel. A metodologia foi aplicada a biodieseis originários de óleo de soja, girassol, frango e sebo bovino, dos quais se avaliaram economicamente os custos fixos e variáveis para conversão química dos óleos e gorduras em ésteres metílicos, em uma planta de produção experimental. Os custos de produção para cada uma das quatro citadas são distintos em função do valor inicial por litro de cada uma. Também fora avaliado o custo específico e o consumo específico de cada um dos biodieseis, a fim de determinar a diferença em relação ao óleo diesel comercial. No estudo de caso, os resultados mostraram vantagens para o óleo diesel, tanto no custo quanto no consumo. Comparando-se os biodieseis, o de sebo bovino apresentou-se com o menor custo de produção e o menor consumo.Considering that Brazil has a wide range of raw materials for biodiesel production, and also the possibility of small scale production, there is a demand for economic methodology studies with easy implementation. The objective of this research was to demonstrate a methodology and its application to assess the costs within the production process and the biodiesel use. The methodology was applied to biodiesels originated from soybean oil, sunflower oil, chicken oil and beef tallow, which assessed the fixed and variable costs for chemical conversion of oils and fats into methyl esters in an experimental production plant. Production costs for each of the four mentioned esters are peculiar due to the initial value of each oil per liter. Also the specific cost and specific fuel consumption were evaluated for each biodiesel to determine the difference with the commercial diesel oil. The case study showed advantages for diesel oil, both in cost and consumption. Comparing the biodiesels, the beef tallow showed the lowest production costs and lower consumption.

Com o objetivo de avaliar a influência de seis lâminas de irrigação no desempenho produtivo de duas cultivares de girassol (Catissol 01 e Embrapa 122 V-2000), realizou-se um ensaio na Fazenda Experimental Vale do Curu, no Município de Pentecoste, CE. O delineamento estatístico adotado foi o de blocos ao acaso, no esquema de parcelas subdivididas, com quatro repetições. Nas parcelas, avaliou-se o efeito de seis lâminas de irrigação baseadas em percentuais da evaporação do tanque classe A (ECA), que corresponderam à multiplicação da ECA pelos fatores 0,25; 0,50; 0,75; 1,00; 1,25 e 1,50 e nas subparcelas, avaliou-se o efeito das duas cultivares. O diâmetro dos capítulos, a massa de 1.000 aquênios, o potencial de produção de aquênios, o teor de óleo dos aquênios e o potencial de produção de óleo foram influenciados significativamente pelas diferentes lâminas de irrigação, sendo que os maiores valores foram obtidos para a cultivar Catissol 01, exceto para o teor de óleo dos aquênios, onde se constatou maiores valores para a cultivar Embrapa 122 V-2000. Houve diferenças significativas entre as cultivares nas variáveis diâmetro de capítulos e potencial de produção de aquênios. A lâmina de irrigação de 533,70 mm (150% da ECA) proporcionou os maiores potenciais de produção de aquênios 4.222,76 e 3.948,02 kg ha-1, e de óleo 1.851,55 e 1.760,63 kg ha-1 para as cultivares Catissol 01 e Embrapa 122 V-2000, respectivamente.With the objective to value the influence of six levels of irrigation in the agricultural performance of two cultivars of sunflower, (Catissol 01 e Embrapa 122 V-2000), was made an experiment at the Experimental Farm, Valley of Curu River,county of Pentecoste, CE. The experimental design adopted was randomized blocks with divided plots, with four replicates. The effect of six levels of irrigation based on percentage of evaporation of class A pan (ECA) by the factors 0.25; 0.50; 0.75; 1.00; 1.25 and 1.50 , was evaluated for the cultivars. The variables, diameter of head, mass of 1000 achenes, potential of production of achenes, content of oil of the achenes, potential of production of oil,were determined. The greater values were achieved by the cultivar "Catissol 01", except for the content of oil of the achenes,higher for the "Embrapa 122 V-2000". There were significant differences between the cultivars in the variable diameter of head and potential production of achenes. The level of irrigation of 533.70 mm (150% of ECA) proportioned the greater potential production of achenes that was of 4,222.76 and 3,948.02 kg ha-1, and of oil 1,851.55 and 1,760.63 kg ha-1 to the cultivars Catissol 01 e Embrapa 122 V-2000, respectively.

Objetivou-se avaliar o efeito do uso de solução nutritiva com ácido, amônio, nitrato e aplicação de solução ácida foliar em plantas de girassol com deficiência de ferro. O experimento foi realizado com a cultura do girassol (Sungro 393) em câmera de crescimento do Laboratório de Nutrição Vegetal da Universidade de Córdoba, Espanha. Inicialmente, as plantas foram cultivadas durante 11 dias, em vasos contendo 0,5 L de solução nutritiva completa (40 µM de Fe). Em seguida, as plantas foram submetidas ao estresse, renovando com a mesma solução nutritiva, diminuindo a concentração de Fe a 5 µM e acrescentando 15 mM de NaHCO3 e CaCO3 a 0,5 g L-1. Nas plantas com a deficiência de ferro, foram aplicados cinco tratamentos, sendo: (a) controle sem Fe, mantendo a mesma solução nutritiva anterior; (b) solução nutritiva com nitrato 2mM Ca(NO3)2; (c) solução nutritiva com amônio, 2mM (NH4)2SO4; (d) solução nutritiva com HCl diluído, pH 3,5; (e) pulverização das folhas com 0,5 mM H2SO4 e com 5 repetições. Realizou-se avaliação da medida indireta da clorofila e a medida do valor pH da solução nutritiva, a partir de 0; 2; 5 e 7 dias após a aplicação dos tratamentos e, na última avaliação, realizou-se a análise química foliar, determinando o teor de Fe total e a matéria seca da planta. O emprego da solução nutritiva com amônio diminuiu o valor pH da solução nutritiva e incrementou o teor foliar de ferro e o valor SPAD das folhas, eliminando os sintomas visuais de deficiência de ferro em plantas de girassol. O uso de amônio na solução nutritiva, durante sete dias, foi mais efetivo na correção da deficiência de ferro em plantas de girassol, comparado com a solução nutritiva com nitrato e com ácido diluído a pH 3,5 e solução ácida foliar.The objective was to evaluate the effect of using a nutrient solution with acid, ammonium nitrate and foliar application of acid solution in sunflower plants with iron deficiency. The experiment was performed with the culture of sunflower (Sungro 393) in slow growth of the Laboratory of Plant Nutrition, University of Cordoba, Spain. Initially the plants were cultivated for 11 days in pots containing 0.5 L of nutrient solution (40 mM Fe). Then the plants were subjected to stress, renewing with the same nutrient solution, decreasing the concentration of 5 mM Fe and adding 15 mM NaHCO3 and CaCO3 0.5 g L-1. In plants with iron deficiency, was submitted to five treatments, consisting of (a) control without Fe, maintaining the same nutrient solution before (b) nitrate nutrient solution with 2 mM Ca (NO3)2, (c) nutrient solution with ammonium 2 mM (NH4)2SO4 (d) nutrient solution with dilute HCl, pH 3.5 (e) spraying the leaves with 0.5 mM H2SO4 and with five replications. We conducted assessment of indirect measurement of chlorophyll and the measured pH value of the nutrient solution, from 0, 2, 5 and 7 days after treatment application and at last assessment was conducted on the foliar analysis by determining the Fe and total plant dry matter. The use of ammonium nutrient solution decreased the pH of nutrient solution and increased the leaf content of iron and the SPAD value of leaves, eliminating the visual symptoms of iron deficiency in sunflower. The use of ammonium in nutrient solution for seven days, was more effective in correcting iron deficiency in sunflower plants, compared with nitrate and with dilute acid at pH 3.5 and acidic leaf.

Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants and can negatively affect plants. Fluorene is a prevalent PAH in the contaminated environment. In this study, the effects of higher concentrations of fluorene in soil on rate of seed germination, growth, and the physiological parameters of wheat, sunflower, and alfalfa were studied. The results showed that the higher concentration of fluorene decreased rate of seed germination and seedlings growth of plants. Wheat showed the highest resistance at seed germination and seedlings growth phases, and sunflower was the most sensitive species at both stages. Therefore, it was concluded that higher resistance at seed germination could be followed by the higher resistance of seedlings. Fluorene toxicity also induced oxidative stress in plants as shown by MDA accumulation in the plants. There was a significant correlation between the lower activity of CAT and MDA accumulation in the studied plants. Therefore, CAT could be an important enzyme involved in detoxification of ROS and plants resistance to fluorene toxicity. Depending on plant species and fluorene concentration, photosynthetic pigments content was differently affected.

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In this study we hypothesized that chaotic or complex behavior of stomatal conductance could improve plant homeostasis after water deficit. Stomatal conductance of sunflower and sugar beet leaves was measured in plants grown either daily irrigation or under water deficit using an infrared gas analyzer. All measurements were performed under controlled environmental conditions. In order to measure a consistent time series, data were scored with time intervals of 20s during 6h. Lyapunov exponents, fractal dimensions, KS entropy and relative LZ complexity were calculated. Stomatal conductance in both irrigated and non-irrigated plants was chaotic-like. Plants under water deficit showed a trend to a more complex behaviour, mainly in sunflower that showed better homeostasis than in sugar beet. Some biological implications are discussed.Este estudo testou a hipótese de que a condutância estomática de uma população de estômatos em uma folha poderia apresentar um comportamento caótico ou complexo sob diferentes condições hídricas, o que poderia favorecer a capacidade homeostática das plantas. A condutância estomática em folhas de girassol e de beterraba cultivadas com irrigação diária e sob deficiência hídrica foi medida com um analisador de gás por infra-vermelho em condições controladas. Os dados foram registrados a cada 20s durante 6h. As séries temporais obtidas foram analisadas por meio dos coeficientes de Lyapunov, dimensão fractal, entropia KS e complexidade LZ relativa. A condutância estomática nas plantas cultivadas com e sem deficiência hídrica exibiu um comportamento provavelmente caótico. As plantas sob estresse hídrico mostraram uma tendência para um comportamento mais complexo, principalmente as plantas de girassol cuja capacidade homeostática foi superior. Algumas implicações biológicas destes comportamentos são discutidas no texto.

O objetivo deste trabalho foi estimar a divergência fenotípica entre 17 genótipos de girassol. O experimento foi conduzido em área experimental localizada no município de Papanduva, SC, na safra 2008/2009. O delineamento experimental utilizado foi de blocos completos casualizados, com quatro repetições. A análise multivariada foi empregada para estimar a divergência fenotípica entre os genótipos, utilizando-se as variáveis canônicas e os métodos de agrupamento de Tocher e UPGMA com base na distância generalizada de Mahalanobis (D2). Análises de variância univariada e multivariada revelaram diferenças entre as cultivares. Os genótipos foram agrupados em três grupos. As características altura de planta aos 70 dias após a semeadura e a produtividade de grãos contribuíram com grande parte da divergência observada.

The study was conducted in two different locations in South Brazil, in tillage in the 2009/2010 season on eight sunflower hybrids, aiming to determine the path correlations and coefficients between primary and secondary characters on the main variable of achene productivity. The correlations were similar between environments. The characters of the capitulum diameter and mass of a thousand achenes had a significant influence on sunflower productivity. Based on the magnitude of the direct and indirect effects, we highlighted all primary components on the main variable, beside the good determination coefficient and low residual effect. The secondary component, the number of achenes, despite the significant direct effect on productivity, was indirectly influenced by the primary components, making it an undesirable character for selection.

Foram estudados os efeitos de três inoculantes microbiológicos na ensilagem do girassol em 16 silos de laboratório confeccionados a partir de baldes plásticos portando válvulas. O girassol, cortado aos 123 dias de crescimento (20,0% de MS e 10,0% de PB), foi homogeneizado e submetido a quatro tratamentos com quatro repetições: controle, Sil-All (S. faecium, P. acidilactici, L. plantarum, amilase, hemicelulase e celulase), Silobac (L. plantarum, S. faecium e Lactobacillus sp.) e Pioneer 1174 (S. faecium e L. plantarum). Os silos foram abertos após 125 dias para análise da composição bromatológica e fermentação. O Pioneer aumentou a concentração de carboidratos solúveis, a concentração de etanol e o poder tampão, diminuiu a concentração de nitrogênio amoniacal, a concentração de ácido acético e o pH, em relação ao grupo controle. Este produto também aumentou a concentração de amido em relação ao grupo controle, enquanto o Sil-All diminuiu. Não foram observados efeitos dos inoculantes sobre a MS, PB, NIDA, FDN, FDA, lignina, digestibilidade in vitro da matéria seca, perdas de matéria seca, estabilidade aeróbia ou sobre as concentrações dos ácidos propiônico, butírico e lático.

O presente trabalho teve por objetivo estimar a perda potencial de rendimento para 36 épocas de semeadura, para a cultura do girassol, em três localidades do Estado de São Paulo: Piracicaba, Ribeirão Preto e Manduri. As estimativas basearam-se nas chances de atendimento das exigências hídricas da cultura e, para tanto, utilizou-se o método da "Zona Agroecológica" para estimativa do rendimento potencial, e o método da FAO de Doorenbos & Kassam, para o cálculo da quebra relativa de rendimento devida à deficiência hídrica, a qual foi estimada pelo balanço hídrico da cultura. Utilizando-se séries históricas que variaram de 28 a 40 anos, foram obtidos resultados que possibilitaram identificar épocas de semeadura de menores riscos para o cultivo do girassol, sob o aspecto hídrico. Em Piracicaba e Ribeirão Preto, os riscos de quebra de rendimento são minimizados quando as semeaduras são realizadas entre 11 de Outubro e 01 de Dezembro, com as quebras sendo inferiores a 10% em cerca de 90% dos casos, podendo a semeadura se prolongar até meados de Fevereiro, porém, com as chances de quebra de rendimento acima de 10% se elevando até cerca de 40%. Em Manduri, em cerca de 85% dos anos ocorreram quebras relativas inferiores a 10% para semeaduras efetuadas entre 21 de Setembro e 11 de Janeiro.The present study was performed to estimate the possible sunflower relative yield loss, for 36 differents sowing dates for three distinct areas in São Paulo, Brazil: Piracicaba, Ribeirão Preto and Manduri. The "Agroecological Zone" method was used to estimate the potential yield, and the crop water balance was used to calculate the relative yield loss caused by water deficit, using the FAO method of Doorenbos & Kassam. It was used historical series of meteorological data ranging from 28 to 40 years to simulate crop-environment relationship. The results showed that in Piracicaba and in Ribeirão Preto, the risks of losses were minimized in sowing between October 11 and December 1st, when less than 10% of yield losses occurred in 90% of the years. Although, in these regions sunflower crop can be sowing until February 11 but with more than 10% losses increasing to 40% of probability. In Manduri, almost 85% of the years had crop yield losses lower than 10% when sowings were made between September 21 and January 11.

O presente trabalho teve por objetivo estimar a perda potencial de rendimento para 36 épocas de semeadura, para a cultura do girassol, em três localidades do Estado de São Paulo: Piracicaba, Ribeirão Preto e Manduri. As estimativas basearam-se nas chances de atendimento das exigências hídricas da cultura e, para tanto, utilizou-se o método da "Zona Agroecológica" para estimativa do rendimento potencial, e o método da FAO de Doorenbos & Kassam, para o cálculo da quebra relativa de rendimento devida à deficiência hídrica, a qual foi estimada pelo balanço hídrico da cultura. Utilizando-se séries históricas que variaram de 28 a 40 anos, foram obtidos resultados que possibilitaram identificar épocas de semeadura de menores riscos para o cultivo do girassol, sob o aspecto hídrico. Em Piracicaba e Ribeirão Preto, os riscos de quebra de rendimento são minimizados quando as semeaduras são realizadas entre 11 de Outubro e 01 de Dezembro, com as quebras sendo inferiores a 10% em cerca de 90% dos casos, podendo a semeadura se prolongar até meados de Fevereiro, porém, com as chances de quebra de rendimento acima de 10% se elevando até cerca de 40%. Em Manduri, em cerca de 85% dos anos ocorreram quebras relativas inferiores a 10% para semeaduras efetuadas entre 21 de Setembro e 11 de Janeiro.

Polycyclic Aromatic Hydrocarbons (PAHs) are diverse organic contaminants released into the environment by both natural and anthropogenic activities. These compounds have negative impacts on plants growth and development. Although there are many reports on their existence in different parts of plant, their uptake and translocation pathways and mechanisms are not well understood yet. This paper highlights the uptake, translocation and accumulation of PAHs by wheat, sunflower and alfalfa through an experimental study under controlled conditions. Seeds were cultivated in a soil containing 50 mg/kg of phenanthrene and fluorene and their concentrations in plants roots and shoots were determined using a gas chromatograph after 7 and 14 days. The results showed that phenanthrene and fluorene concentrations in the treated plants were increased over the time. PAHs bioavailability was time and species dependent and generally, phenanthrene uptake and translocation was faster than that of fluorene, probably due to their higher Kow. Fluorene tended to accumulate in roots, but phenanthrene was transported to aerial parts of plants. [ABSTRACT FROM PUBLISHER]

Background: Polycyclic aromatic hydrocarbons (PAHs) are widespread organic pollutants releasedinto the environment by both natural and anthropogenic processes. PAHs can negatively affectdifferent aspects of plant growth and development. However, the mechanisms of PAHs effects andphysiological response of plants to PAHs have not been adequately studied. Accordingly, the aim ofthis study was evaluation of the germination, growth and physiological responses of wheat,sunflower and alfalfa to phenanthrene toxicity. Material and Methods: This experiment was conducted as a pot culture of plants using a completely randomised design (CRD) with four replications. Plants were cultivated in soil containing 50 and 100 mg kg-1 of phenanthrene for 14 days under greenhouse conditions. All biochemical assays were performed spectrophotometrically after the determination of growth parameters.Results: Soil contamination with phenanthrene differently decreased seed germination and the subsequent seedling growth of plants. Alfalfa showed the highest resistance at both the seed germination and seedling growth phases. Wheat and sunflower were the most sensitive species at the seed germination stage and seedling growth phase, respectively. Phenanthrene contamination induced oxidative stress in plants and POD was determined to be the important enzyme involved in ROS detoxification.Conclusions: Phenanthrene effects on seed germination, seedling growth and physiological parameters of plants are species-dependent. The induction of oxidative stress and decrease in photosynthetic pigments content are two of the reasons for lower plant growth in phenanthrenecontaminated soil, and POD was an important enzyme in the detoxification of ROS. At least in some species, the higher resistance at seed germination could be followed by the higher resistance of seedlings to PAHs. [ABSTRACT FROM AUTHOR]

Plant growth promoting rhizobacteria (PGPR) directly promote plant growth by providing indole-3-acetic acid (IAA), solubilization of inorganic phosphates, nitrogen fixation and siderophores and other organic acid production, whereas indirectly support plant growth by suppressing plant pathogens. The objective of this study was isolation and characterization of bacterial strains from rhizosphere, endosphere and rhizoplane of sunflower. Thirty six bacterial strains were selected out of 44 from plant root samples along with rhizospheric soil, collected from different salt affected areas of Central Punjab (Pakistan). Selected bacterial strains were characterized morphologically as well as biochemically at National Agricultural Research Centre, Islamabad during 2011-13. It was observed that all isolates produced IAA, whereas14 strains were declared as phosphate solubilizing bacteria (PSB), eight isolates exhibited antifungal characteristics, 30 were nitrogen fixer and all of them were gram -ve. During biochemical characterization of bacterial isolates KS 15 and KS 8 produced the highest indole acetic acid whereas KS 15 and KS 17 indicated maximum phosphate solubilization (PS) among all isolated strains. The bacterial strains KS 10 and KS 44 showed maximum bio-control activity (fungal growth inhibition) than other isolated strains. [ABSTRACT FROM AUTHOR]

The population of urban centers is growing very quickly, resulting in na increase in waste production, or increased production of sewage sludge. The biggest concern for the use of sewage sludge in agriculture is the increasing concentration of toxic elements in soil. The aim of this study was to evaluate the behavior of heavy metals in soil, plant and grain of sunflower at different dosages and management of sewage sludge. The experiment was conducted at the São Manuel belonging to the Faculdade de Ciência Agronômica, UNESP Campus de Botucatu. We adopted the experimental design of randomized blocks consisting of five treatments and five replications. The treatments were: T1 - 50 kg ha-1 de N mineral fertilizer; T2 - 25 kg ha-1 de N from sewage sludge and 25 kg ha-1 of mineral fertilizer; T3 - 50 kg ha-1 de N sewage sludge; T4 - 75 kg ha-1 de N from sewage sludge; T5 - 100 kg ha-1 de N from sewage sludge. There was no variation of the toxic elements in the leaf, seeds and export of nutrients in the seeds. The sewage sludge did not cause increase in levels of toxic elements in the to 40 cm deep. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants and can negatively affect plants. Fluorene is a prevalent PAH in the contaminated environment. In this study, the effects of higher concentrations of fluorene in soil on rate of seed germination, growth, and the physiological parameters of wheat, sunflower, and alfalfa were studied. The results showed that the higher concentration of fluorene decreased rate of seed germination and seedlings growth of plants. Wheat showed the highest resistance at seed germination and seedlings growth phases, and sunflower was the most sensitive species at both stages. Therefore, it was concluded that higher resistance at seed germination could be followed by the higher resistance of seedlings. Fluorene toxicity also induced oxidative stress in plants as shown by MDA accumulation in the plants. There was a significant correlation between the lower activity of CAT and MDA accumulation in the studied plants. Therefore, CAT could be an important enzyme involved in detoxification of ROS and plants resistance to fluorene toxicity. Depending on plant species and fluorene concentration, photosynthetic pigments content was differently affected. [ABSTRACT FROM AUTHOR]