Sunflower Cultivars Research Articles

Host range and risk assessment of Zygogramma bicolorata, a defoliating agent released in South Africa for the biological control of Parthenium hysterophorus

Parthenium hysterophorus (parthenium) is a weed of international importance and is spreading rapidly in sub-Saharan Africa. Consequently, it has been targeted for biocontrol in South Africa since 2003. Based on precedents elsewhere in the world, the defoliating beetle Zygogramma bicolorata was prioritised as a candidate agent. Although no-choice tests, involving some 48 test plant species, indicated a significant preference for parthenium, significantly reduced feeding and oviposition was recorded on some species. Multiple-choice tests resolved many of these non-target results; however, Helianthus annuus (sunflower) was still selected for oviposition and feeding. Of the 12 sunflower cultivars tested, four were selected for oviposition, while two were selected for oviposition and feeding. These six cultivars were then subjected to larval development trials, together with three native and two weed species (in the Asteraceae). These trials showed high levels of complete development on parthenium, significantly reduced development on sunflower cultivars, and partial development on only one of the weed species. Finally, a risk assessment was conducted on the six sunflower cultivars to quantify Z. bicolorata feeding and reproductive performance. Feeding risk calculations revealed these cultivars to have an extremely low risk (<0.2%) of supporting Z. bicolorata feeding and development. Similarly, reproductive risk calculations showed a very low risk (<0.16%) of supporting viable Z. bicolorata populations. These data are supported by findings from both the native (Mexico) and introduced ranges (Australia, India) of Z. bicolorata, where it has never been recorded as a pest of sunflower. These considerations were accepted by the regulatory authorities and in August 2013, Z. bicolorata became the second insect agent to be released in South Africa for the biocontrol of parthenium.

Broad resistance to acetohydroxyacid-synthase-inhibiting herbicides in feral radish (Raphanus sativus L.) populations from Argentina.

Soon after the commercial release of sunflower cultivars resistant to imidazolinone herbicides, several uncontrolled feral radish (Raphanus sativus L.) populations were found in south-eastern Buenos Aires, Argentina. These populations were studied in field, glasshouse and laboratory experiments aiming to characterise their resistance profile and to develop management tools. Three feral radish accessions were highly resistant to ten active ingredients of five families of acetohydroxyacid synthase (AHAS)-inhibiting herbicides. Sequence analysis of the AHAS gene detected a Trp574Leu mutation in all resistant accessions. One accession with an intermediate level of resistance was heterozygous for this mutation, probably owing to gene exchange with a susceptible subpopulation located in the field margin. Herbicide-resistant and herbicide-susceptible radish could be controlled in sunflower by alternative herbicides. This is the first report of feral radish with resistance to herbicides belonging to all the AHAS-inhibiting herbicide families, conferred by Trp574Leu mutation in the AHAS gene. An appropriate herbicide rotation with alternative herbicides such as fluorochloridone or aclonifen and an increase in the diversity of cropping systems are important for minimising the prevalence of these biotypes.

Determination of the tolerance of sunflower to lead-induced stress

Six-week old sunflower seedlings, cv. Ogrodowy, were treated with 0, 15, 45 and 60 mg Pb dm-3, and then the content of lead and selected physiological and biochemical parameters were measured. Photosynthesis efficiency, water relations (intensity of transpiration, relative water content (RWC)) and gene-encoding metallothionein were measured three times after 24, 48 and 72 hours of exposure to Pb. The content of glutathione and lead was analysed after 72 hours’ exposure to Pb. Most of the lead uptake was accumulated in the roots, then in the stems and leaves, but when re-calculated per plant dry weight, the uptake of the metal did not depend on the lead dose applied. The highest 60 mg Pb dm-3 treatment was accompanied by a significant decrease in dry weight content. Moreover, most of the lead taken up in these plants was transported to the stems and leaves (23.6% of total lead uptake). The lead doses used in this study did not affect the intensity of photosynthesis, but a decrease in transpiration and relative water content was observed. The glutathione level in the plants varied depending on the organ examined and the Pb concentration in the treatment. The expression of the metallothionein gene HaMT1 was observed in the stems only. These results indicate that the sunflower cultivar Ogrodowy is a promising plant for phytoremediation of lead-polluted soils.

Optimum plot size for experiments with the sunflower1

The aim of this study was to determine a suitable plot size for field experiments with the sunflower. An experiment was carried out in a randomised complete block design with 14 sunflower cultivars and 10 replications. The plots consisted of four rows, six metres in length, spaced 0.7 m apart with 0.3 m between plants. The working area of the plot (7.56 m 2 ), consisting of the two central rows, was divided into 12 basic units, each consisting of three plants per row (0.63 m 2 ), from where the yield of the sunflower seeds was obtained. Suitable plot size was estimated using the intraclass correlation coefficient method. The detectable difference between treatments was also estimated (d). The optimum plot size for the evaluation of grain yield in the sunflower was 2.52 m 2 (working area), considering a boundary of one row on each side. Greater gains in experimental precision (16%) with increases in plot size, occurred up to eight basic units (5.04 m 2 ) using seven replications. Increasing the number of replications and the plot size was more efficient

Effects of foliar spray of two kinds of zinc oxide on the growth and ion concentration of sunflower cultivars under salt stress

ABSTRACTThis study investigated the effects of foliar application of normal and nano-sized zinc oxide on the response of sunflower cultivars to salinity. Treatments included five cultivars (‘Alstar’, ‘Olsion’, ‘Yourflor’, ‘Hysun36’ and ‘Hysun33’), two salinity levels [0 and 100 mM sodium chloride (NaCl)], and three levels of fertilizer application. Fertilizer treatments were the foliar application of normal and nano-sized zinc oxide (ZnO). Foliar application of ZnO in either forms increased leaf area, shoot dry weight, net carbon dioxide (CO2) assimilation rate (A), sub-stomatal CO2 concentration (Ci), chlorophyll content, Fv/Fm, and Zn content and decreased Na content in leaves. The extent of increase in chlorophyll content, Fv/Fm and shoot weight was greater as nano-sized ZnO was applied to the normal form. The results show that the nano-sized particles of ZnO compared to normal form has greater effect on biomass production of sunflower plants.

Boron Fertilization in Sunflower (Helianthus annuus L.) in an Inceptisol of West Bengal, India

This study is a synthesis of information on growth, yield, and boron-use efficiency of hybrid sunflower (cultivar Aditya) in an inceptisol (Gangetic alluvium) of West Bengal, India, under varied proportions of soil and foliar-applied boron. Foliar spray of boron (B), under all circumstances, performed better than soil application of B fertilizers with regard to sunflower seed and total dry-matter yield, B uptake, and B-use efficiencies, while 0.2 percent foliar B spray was associated with greatest B recoveries, B-use efficiencies, and sunflower seed yields in the experimental years.

Pre-sowing Seed Treatment with Proline Improves some Growth, Biochemical aspects, yield quantity and quantity of two sunflower cultivars grown under seawater salinity stress

Pre-sowing Seed Treatment with Proline Improves some Growth, Biochemical aspects, yield quantity and quantity of two sunflower cultivars grown under seawater salinity stress

English

The cultivated area of sunflower in Brazil is expanding considerably over the last years as the result of the great interest in the biodiesel production derived from that crop. One consequence of that expansion is the occurrence of several diseases some of devastating nature in part of the growing areas with sunflower. This study evaluated the effects of the association of sunflower seeds infected by Sclerotinia sclerotiorum and the pathogen transmission rates from these infected seeds, considering some factors which may interfere in that interaction. Four inoculum potentials, two isolates of the cited fungus, two sunflower cultivars, 'Helio 250' and 'Helio 253' and two environmental temperatures, 20°C and 25°C, were used for the purpose in this work. Seed germination and health, emergence speed index, and plant populations were variables analyzed. From the results, increased levels of inoculum potentials led to gradual reduction of the mean values of germination, emergence rate index and plant populations, regardless the genotype, fungal isolates and temperatures. Transmission rates were higher at the highest levels of inoculum potential, the maximum reaching 80%. These results show the significance of S. sclerotiorum inoculum associated with sunflower seeds both in the establishment of plants in fields and also in spreading the pathogen inoculum between crop fields.

Comparative analysis of fatty acids, tocopherols and phytosterols content in sunflower cultivars (Helianthus annuus) from a three-year multi-local study

Sunflower oil is naturally rich in both unsaturated fatty acids and numerous minor components, with high levels of &-tocopherol and phytosterols that could play an important role in plant protection. These micronutriments, tocopherols and phytosterols, also exhibit health benefits for humans including reducing both cardiovascular diseases and aging disorders. &−Tocopherol represents more than 95% of total sunflower tocopherol and has the greatest vitaminic activity. Furthermore, this oil contains high amounts of β-sitosterol which is a promising health beneficial phytosterol. The objective of this study was to compare the content and composition of fatty acids, tocopherols and phytosterols in sunflower oil between different cultivars and locations in a three-year experiment, and to estimate the relationships between these minor components, fatty acids and climatic conditions. Results revealed that content and composition of these molecules are mainly determined by plant genotype. Nevertheless, the environmental conditions seemed to strongly influence the tocopherol content. The results suggest possible improvement in sunflower breeding for minor components.

Impact of Inorganic Arsenicals on Vegetative Growth of Two Pakistani Origins Sunflower Cultivars

Inorganic arsenicals impact on vegetative growth of two sunflower (Helianthus annuusL.) cultivars (FH-385 as Hybrid 1 and FH-405 as Hybrid 2) was monitored. Various levels of two different sodium salts of arsenic, namely, sodium arsenate (Na2HAsO4·7H2O) as source of As5+and sodium arsenite (NaAsO2) as source of As3+, were used to evaluate the effect of arsenic on plant water relation parameters. Significant stress effects were found when arsenic was higher in concentrations (&gt;60 mg/kg soil of both salts) as compared to control plants. Genotype FH-405 showed higher levels for shoot and root length, water contents, number of leaves, and leaf area, which indicates well adaptation of this cultivar in arsenic contaminated environment. T5 (100 mg/kg) of both salts showed notable stressful impacts as compared to low arsenic concentrations (20, 40 mg/kg) and especially control plants in case of all morphophysiological parameters of sunflower cultivars.

Tamanho ótimo de parcela para avaliação do rendimento de grãos do girassol

Propôs-se, neste trabalho, determinar o tamanho adequado de parcela para avaliação do rendimento de grãos do girassol, razão pela qual foi realizado, no período de maio a julho de 2011, um experimento no delineamento em blocos completos casualizados com 14 cultivares de girassol e 10 repetições. As parcelas foram constituídas de quatro fileiras com seis metros de comprimento espaçadas de 0,7 m e entre plantas de 0,3 m. A área útil da parcela, composta das duas fileiras centrais, foi dividida em 12 unidades básicas (UBs) cada uma de três plantas na fileira, medindo-se o rendimento de grãos do girassol por unidade básica. O rendimento de grãos das UBs adjacentes foi agrupado de modo a formar sete tipos de parcelas de cinco tamanhos diferentes pré-estabelecidos. O tamanho ótimo da parcela experimental foi estimado por meio do método da máxima curvatura modificado (3,74 m2) e do modelo linear segmentado com platô (2,48 m2) cujo tamanho de 3,74 m2 de área útil foi considerado adequado para avaliação do rendimento de grãos do girassol e menor que o tamanho geralmente usado nas pesquisas com o girassol.

Drip irrigated sunflower intercropping

One of the difficulties in the implementation of agroenergy’s cropping is the growing area competition with subsistence crops. Few studies have been conducted to show the efficiency of intercropping between plants of energy’s potential with cultures of economic sustainability. The objective of this study was to evaluate the effectiveness of intercropping sunflower cultivars with corn and beans, in the initial growth under localized irrigation. The experiment was conducted at the end of the year 2012, in an area of 950 m2, located in the Campus II-UEPB, Lagoa Seca, Paraiba. The irrigation system was managed based on the Reference Evapotranspiration (ETo), calculated by the Penmann-Monteith Method with data obtained locally. The experimental design was a randomized blocks factorial (2 × 4) × 3, with treatments combining two varieties of sunflower in four plantation systems: single or isolated, intercropped with maize, with bean and with caupi. Each plot consisted of four rows of sunflowers in spacing 0.3 × 0.7 m and length of 5 m, interspersed with rows of beans or corn, except in the isolated system. The central rows of sunflowers were used to measure the following growth characteristics: plant height, stem diameter, number of leaves and leaf area. Data were subjected to analysis of variance by F test and the means compared by Tukey test at 5% probability. The diversification of sunflower varieties promoted differences in initial growth, regardless of the cropping system. There was significant effect at 15 DAS, where the sunflower variety “Advanta CF101” had higher plants than the variety “Helio 253” at 40 DAS; the variety “Helio 253” had a stem diameter greater than the “Advanta CF101”.

Effect of Mineral Fertilization and Irrigation on Sunflower Yields

Among the cultures used for the production of biofuels, the sunflower is one of the most important. Although some information exists, the water and nutritional needs of sunflower in the north east of Brazil are not well known. To fill knowledge gaps, an experiment was carried out to evaluate the effect of nitrogen (N), phosphorus (P), potassium (K) fertilization and available soil water (ASW) on sunflower yields. The sunflower cultivar Embrapa 122-V2000 was subjected to 44 treatments on a completely randomized design generated by the Baconian Matrix with four rates of N (0, 60, 80 and 100 kg&middotha-1), four rates of P2O5 (0, 80, 100 and 120 kg&middotha-1), four rates of K2O (0, 80, 100 and 120 kg&middotha-1), and four available soil water (ASW) levels (55%, 70%, 85% and 100%) replicated three times. Urea was used as a source of N, triple super phosphate as P and potassium chloride as K. In all the experimental units was applied 2 kg&middotB&middotha-1 as boric acid. The components of production evaluated were dry matter of the head, total number of achenes, total achenes’ weight and 1000 achenes’ weight. The results of this research showed that nitrogen had a significant effect on the dry matter of the head, total number of achenes and total achenes’ weight. Phosphorus affected all production components and potassium affected the total number and the weight of achenes. With the exception of the 1000 achenes’ weight, all the production components of the sunflower increased with the increased ASW level influenced significantly at 0.01 level of probably the total number of achenes. The highest rates of N, P and K (100, 120 and 120 kg&middotha-1, respectively) and 100% of available soil water produced the highest production.

EFFECT OF POTASSIUM FERTILIZATION LEVELS ON GROWTH, YIELD AND QUALITY OF SUNFLOWER CULTIVARS (Helianthus annuus L.)

The study included two field experiments for sunflower crop conducted during spring growing season of 2008 in two locations. The first was in AL-Rashidia (20 km) west north Mosul city, the second ones was in AL-Hamdanea (30 Km) east of Mosul city. The main objective was to find out the effect of potassium fertilization levels on growth, yield and quality of three sunflower cultivars. Each experiment was conducted according to factorial experiment in a randomized completely block design with three replications. It included three levels of potassium (0, 30 and 60 kg k per hectare -1 ) were applied to the soil during the sowing period, with three cultivars of sunflower crop (Saturn, Gordis and Majak). The results could be summarized as follows: The cultivar Gordis gave a high level for most growth, yield and quality parameters in both locations. Application of 30 kg K per hectare -1 led to a significant increase in plant height, leaf area, disc diameter, number of seeds per head, weight of thousand seed, seed yield, oil percentage and oil yield, while increasing concentration of potassium up to 60 kg K per hectare -1 caused a significant increase in protein percentage in AL-Rashidia and AL-Hamdanea locations. The interaction between the cultivars and potassium fertilization levels was significant in some growth, yield and quality parameters, the Gordis cultivar with potassium application to the soil with concentration 30 kg k.ha -1 was superior and gave highest values for plant height, stem diameter, leaf area, number of seeds.head -1 , weight of thousand seed, oil percentage, oil yield, protein percentage

The effect of drought stress on yield and yield components of promising cultivars of sunflower

In order to study the effect of drought stress on the agronomical traits of different cultivars of sunflower, an experiment was conducted in 2013 at the Agricultural Research Station of Islamabad Gharb, Kermanshah province, Iran. The experiment was conducted in factorial in the form of a randomized complete block design with three replications. Drought stress was the first factor in three levels: normal irrigation after 60 mm evaporation from an A Class evaporation pan (control), irrigation after 120 and 180 mm evaporation from the pan, at the beginning of the flowering stage. Cultivar was the second factor in 12 levels: Farrokh, Ghasem, SHF81-90, Barzegar, G5*43, G6*43, Hysun 25, Euroflor, Hysun 36, Azargol, Sumbro and Sirena. Results indicated that reducing the irrigation, especially severe drought stress, had adverse effect on the measured traits. The effect of cultivar was also significant on head diameter, 1000 grain weight and grain yield. The interaction of irrigation × cultivar had only a significant effect on 1000 grain weight. Results showed that Barzegar cultivar had the highest grain yield under normal irrigation (4767.66 kg/ha), moderate stress (3850.66 kg/ha) and extreme stress (3208.33 kg/ha).

Anatomy of Petal Drop in Sunflowers

The petals of some sunflower (Helianthus annuus) cultivars used as cut flowers are easily knocked off the flower; this ruins its appearance and destroys its market value. The objectives of this study were to characterize an abscission zone, if present, at the base of petals of sunflower florets in cultivars that differ with respect to petal drop and to determine if differences in the nature and/or development of the abscission zone among cultivars were correlated with differences in timing with respect to petal drop. In the first experiment, we measured the force required to pull petals from the flower head; in the second we investigated changes in the anatomy of the petal–achene juncture. Anatomical analysis revealed a differentiated region (the abscission zone) at the junction of the petal and achene consisting of cells with a different morphology from those above and below it. Cell division at the abscission zone of the short-lived cultivar occurred earlier than in the long-lived cultivar. These differences indicate that whereas the anatomical nature of the abscission zone is similar in the two cultivars, Procut Yellow Lite (PYL) and Procut Bicolor (PBC), the tempo of development differed. Specifically, the abscission layer reached full differentiation, or maturity, sooner in PBC, hence its earlier petal drop, than in PYL.

Differences in sensitivity of F1 and F2 generations of herbicide tolerant sunflower volunteers to selected acetolactate synthase inhibiting herbicides

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&amp;ndash;75%). F2 generation of non-HT sunflower showed a low level of sensitivity to imazamox (efficacy 10&amp;ndash;43%) and to nicosulfuron, tribenuron, thifensulfuron and rimsulfuron under dry conditions (efficacy 43&amp;ndash;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&amp;ndash;100%) &amp;gt; florasulam (88&amp;ndash;100%) &amp;gt; foramsulfuron (40&amp;ndash;98%) &amp;gt; thifensulfuron (12&amp;ndash;99%) &amp;gt; rimsulfuron (37&amp;ndash;99%) &amp;gt; tribenuron (0&amp;ndash;87%) &amp;gt; nicosulfuron (0&amp;ndash;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%) &amp;gt; imazamox (0&amp;ndash;17%) &amp;gt; nicosulfuron (0&amp;ndash;43%) &amp;gt; thifensulfuron (0&amp;ndash;57%) &amp;gt; rimsulfuron (0&amp;ndash;70%) &amp;gt; foramsulfuron (8&amp;ndash;75%) &amp;gt; florasulam (75&amp;ndash;96%) &amp;gt; iodosulfuron (87&amp;ndash;98%). Sensitivity of F2 generation of ExpressSun to tested herbicide was usually higher as compared to F1 generation.

Screening Ornamental Sunflowers in the Seedling Stage for Flowering Reaction to Photoperiod

Ornamental sunflower (Helianthus annuus) cultivars grown as cut flowers range in sensitivity to photoperiod with regard to flowering from facultative short day (SD) to facultative long day (LD), with others insensitive to daylength. SD sensitivity is a problem for production in tropical areas, or in early spring sowings when the daylength triggers early flowering, and leads to small flowers and production of unsightly axillary buds. In the current work, 59 cultivars of sunflower were exposed to either 12- or 16-hour photoperiod in seedling trays in a greenhouse for 3 weeks, and transplanted outside. At flowering, plant height, leaf number, and flower diameter were measured. The studies were conducted in 2006, 2007, 2009, 2011, and 2012 with two cultivars (Procut Lemon and Sunrich Orange) serving as controls in each trial. Of the 59 cultivars screened, 52% were found to be day-neutral, 44% were SD, and two (3%) had a LD reaction. Two standard cultivars grown in each season showed consistent reactions to the photoperiod treatments in each year. The seedling screen is useful to identify cultivars suited for production in early spring in a temperate environment.

Transitions in photoperiodic flowering are common and involve few loci in wild sunflowers (Helianthus; Asteraceae).

• Evolutionary changes in how flowering time responds to photoperiod cues have been instrumental in expanding the geographic range of agricultural production for many crop species. Locally adaptive natural variation in photoperiod response present in wild relatives of crop plants could be leveraged to further improve the present and future climatic ranges of cultivation or to increase region-specific yields. Previous work has demonstrated ample variability in photoperiod response among wild populations of the common sunflower, Helianthus annuus. Here, we characterize patterns of photoperiod response variation throughout the genus and examine the genetic architecture of intraspecific divergence.• The requirement of short day lengths for floral induction was characterized for a phylogenetically dispersed sample of Helianthus species. In addition, flowering time was assessed under short days and long days for a population of F3 individuals derived from crosses between day-neutral and short-day, wild H. annuus parents.• An obligate requirement for short-day induced flowering has evolved repeatedly in Helianthus, and this character was correlated with geographic ranges restricted to the southern United States. Parental flowering times under long days were recovered in high proportion in the F3 generation.• Together, these findings (1) reveal that substantial variation in the nature of flowering time responses to photoperiod cues has arisen during the evolution of wild sunflowers and (2) suggest these transitions may be largely characterized by simple genetic architectures. Thus, introgression of wild alleles may be a tractable means of genetically tailoring sunflower cultivars for climate-specific production.

Variability in cadmium and zinc shoot concentration in 14 cultivars of sunflower (Helianthus annuus L.) as related to metal uptake and partitioning

AimsCadmium (Cd) is a very toxic metal in soils, contaminating agricultural crops due to its absorption by roots. Among crops, sunflower (Helianthus annuus L.) accumulates relatively high amounts of Cd. This work examined the variability of Cd and zinc (Zn) in shoots of sunflower cultivars and investigated if the variability was linked to the shoot growth, to the metal uptake and to the metal partitioning aboveground. MethodsFourteen cultivars of sunflower were cultivated in a nutrient solution containing 20nM of Cd(NO3)2 and 760nM ZnSO4. The between-cultivar variability for the total Cd and Zn content in root and shoot biomass was determined at the 6–8 leaf stage and possible correlations with the biomass and root architecture were investigated. ResultsCd and Zn concentrations in shoots differed between cultivars by a factor of 2.3 and 2.2, respectively. Metal uptake was more positively correlated with shoot biomass than with root biomass and was not correlated with root architecture. The between cultivar differences for metal concentration in shoots was explained by differences in uptake relative to shoot growth and for Cd, by the partitioning of the metal between roots and shoots. ConclusionsThis study suggests that Cd root uptake relative to shoot growth and Cd partitioning to shoots could be targets for selecting cultivars having a low (for crop quality) or a high (for phytoextraction) Cd content aboveground.