Improvement of essential oil yield of oil-bearing (Rosa damascena Mill.) due to surfactant and maceration

The essential oil content of the oil-bearing rose (Rosa damascene Mill.) is relatively low, around 0.3-0.4 mL kg⁻¹ in fresh flowers. There is a need to increase essential oil yield of oil-bearing rose. The objective was to examine the effect of Tween 20 (polyoxyethylene sorbitan monolaurate) applied with, or without, maceration of flowers on oil content and composition of oil-bearing rose harvested at beginning of flowering, full bloom, and end of flowering. Addition of Tween 20 at 1000 mL L⁻¹ and 2500 mL L⁻¹ increased essential oil yield by 26% (to 0.44 mL kg⁻¹) and 54% (to 0.54 mL kg⁻¹) respectively relative to the untreated control that gave 0.35 mL kg⁻¹ yield. Maceration, in combination with the addition of Tween 20 at 1000 mL L⁻¹ and Tween 20 at 2500 mL L⁻¹, increased oil yield by 69% (to 0.59 mL kg⁻¹) and 94% (to 0.68 mL kg⁻¹) respectively. Among the three phenological phases of harvest, harvesting at the beginning of flowering gave the highest yield followed by the full bloom and then by the end of flowering phases. Since the interaction effect was not significant, the differences obtained among the treatments were regardless of the phase, and vice versa. Treatments did not significantly alter composition of the essential oil. Postharvest pre-extraction application of Tween 20 in combination with maceration could be used in the rose industry for increasing the essential oil yield.     

Characteristics, chemical composition and utilisation of Albizia julibrissin seed oil

The physicochemical characteristics, fatty acid and triacylglycerol compositions, DSC profile and UV/vis spectrum of oil extracted from Albizia julibrissin seeds were determined in this study. The oil content and the moisture of the seeds were 10.50% and 1.56%. The free fatty acid, the peroxide value, the p-anisidine value, the saponification value, the iodine value were 2.54%, 6.61 mequiv. O₂/kg of oil, 1.98, 190.63 (mg KOH/g) and 111.33 (g/100 g of oil), respectively. The specific extinction coefficients K₂₃₂, K₂₆₈ were 7.55 and 0.96, respectively. Linoleic acid (C_18:2, 58.58%), palmitic acid (C₁₆, 13.86%) and oleic acid (C_18:1, 10.47%) were the dominant fatty acids in the A. julibrissin seed oil. LLL (36.87%), OLL (21.62%), PLL (16.69%) and PLO + SLL (8.59%) were the abundant triacylglycerol representing > 83% of the seed oil (L: linoleic, O: oleic, P: palmitic, S: stearic). The DSC melting curves reveal that: melting point = −14.70° C and melting enthalpy = 54.34 J/g. A. julibrissin seed oil showed some absorbance in the UV-B and UV-C ranges. The results of the present analytical study show that A. julibrissin is a promising oilseed crop, which can be used for making soap, hair shampoo and UV protectors. Furthermore, the high level of unsaturated fatty acids makes it desirable in terms of nutrition.     

Activities of essential oils from Asarum heterotropoides var. mandshuricum against five phytopathogens

Some secondary metabolites of plants function as antimicrobial products against phytopathogens and constitute an increasingly important class of pesticides. In the present study, the essential oil of Asarum heterotropoides var. mandshuricum was analyzed by GC/MS and its antimicrobial activity was evaluated against five phytopathogenic fungi. Major components of the oil were methyleugenol (59.42%), eucarvone (24.10%), 5-allyl-1,2,3-trimethoxybenzene (5.72%), and 3,7,7-trimethylbicyclo(4.1.0)hept-3-ene (4.93%). The essential oil and the most abundant component, methyleugenol, were separately assayed for inhibition of 5 pathogens: Alternaria humicola, Colletotrichum gloeosporioides, Rhizoctonia solani, Phytophthora cactorum and Fusarium solani. Both the oil and methyleugenol strongly inhibited the growth of the test pathogens (IC₅₀ values <0.42 μg ml⁻¹) except F. solani, with the best activity against P. cactorum (IC₅₀ values = 0.073 and 0.052 μg ml⁻¹, respectively). It is concluded that the essential oil of A. heterotropoides var. mandshuricum has a broad antiphytopathogenic spectrum, and that methyleugenol is largely responsible for the bioactivity of the oil. The mode of action of methyleugenol against P. cactorum is discussed based on changes in the mycelial ultrastructure.     

Lavender and hyssop productivity, oil content, and bioactivity as a function of harvest time and drying

Field and laboratory experiments were conducted to evaluate the productivity and essential oil composition of lavender (Lavandula angustifolia Mill.) and hyssop (Hyssopus officinalis L.) as functions of year, harvest time, and drying. Lavender essential oil content ranged from 0.71 to 1.3% (overall average of 0.89%) and hyssop oil content ranged from 0.13 to 0.26% (overall average of 0.19%). Lavender and hyssop essential oil yields increased with time. Hyssop oil yields varied from 7.3 kg ha⁻¹ to 19.6 kg ha⁻¹, and lavender oil yields varied from 7.8 kg ha⁻¹ to 55.5 kg ha⁻¹. The major constituents of lavender oil were linalool (23.3-43.4%) and linalylacetate (20.2-39.6%), while the major constituents of hyssop oil were pinocamphene + isopinocamphene (57-75%) and β-pinene (5-15%). Lavender oil extracted from dry material had higher concentrations of linalyl acetate and caryophyllene but lower concentrations of myrcene than the oil from the fresh material. Delayed harvest of hyssop increased the concentrations of β-pinene, myrcene, and limonene + cineole but reduced pinocamphone + isopinocamphone. The chemical composition of the lavender and hyssop oil produced in Mississippi was similar to commercial oils from Bulgaria, Canada, France, and US. Lavender and hyssop can be established as essential oil crops in areas of the southeastern United States. Lavender and hyssop essential oils did not show significant antimicrobial, antileishmanial, antimalarial activity, and did not alter ruminal fermentation. However, commercial oil from L. latifolia reduced methane production in an in vitro digestibility study. The antioxidant activity of hyssop essential oil was 2039 μmol of TE L⁻¹, whereas the antioxidant activity of lavender essential oil was 328 μmol of TE L⁻¹.     

Chemical profiles of primary and secondary essential oils of palmarosa (Cymbopogon martinii (Roxb.) Wats var. motia Burk.)

Natural essential oils extracted from aromatic crops through steam distillation are extensively used in fragrance, flavour and pharmaceutical industries and in aromatherapy. During steam distillation, a part of the essential oil becomes dissolved in condensate or distillation water and is lost as this water is discarded. A method was developed to recover the dissolved essential oil from condensate water. Palmarosa (Cymbopogon martinii (Roxb.) Wats. var. motia Burk., family: Poaceae), an important aromatic grass was used as the test crop. The distillation water of palmarosa mixed with hexane in 10:1 proportion was thoroughly shaken for 30 min to trap the dissolved essential oil. Hexane was then distilled to yield ‘secondary’ or ‘recovered’ oil. In palmarosa, the ‘primary’ or ‘decanted’ oil (obtained directly by distilling the crop biomass) accounted for 92% and the recovered oil accounted for 8% of the total oil yield. The solvent loss in this process was 4–7%. Experiments conducted in the laboratory with the essential oil showed that the water solubility of palmarosa oil ranged from 0.12 to 0.15% at 31 °C and 0.15 to 0.20% at 80 °C. Hexane recovered up to 97% of the dissolved essential oil in water. The recovered essential oil was richer in organoleptically important oxygenated compounds linalool (2.6–3.8%), geraniol (91.8–92.8%) and geranial (1.8–2.0%) compared to the primary oil.     

Synthesis of Jatropha curcas oil-based biodiesel in a pulsed loop reactor

Jatropha curcas oil (JCO) has a high content of free fatty acids and has been used extensively as a feedstock in biodiesel production. In the present study, the transesterification reaction of JCO to Jatropha curcas methyl ester (biodiesel) was performed in a continuous pulsed loop reactor under atmospheric conditions. The JCO was pre-treated prior to the reaction to reduce the free fatty acid content to below 1% (w/w). The operating parameters of the loop reactor were optimised based on the conversion of the JCO to Jatropha curcas biodiesel and included reaction temperature, molar ratio of oil to MeOH, reaction time and oscillation frequency. The findings show that the highest reaction conversion of 99.7% (w/w) was achieved using KOH catalyst and 98.8% conversion was obtained using NaOCH₃ catalyst. The optimal operating conditions were a molar ratio of 6:1, an oscillation frequency of 6 Hz, temperature of 60 °C, feedstock FFA content of 0.5% (w/w) and only 10 min of reaction time. As a commercial commodity, the physical properties of biodiesel were analysed, and they compared well with the characteristics of fossil-based diesel fuel.     

Effect of residual distillation water of 15 plants and three plant hormones on Scotch spearmint (Mentha × gracilis Sole)

Distillation waste water is a byproduct from steam distillation of aromatic crops, and is currently discharged into streams and rivers. We evaluated distillation waste water (extract) from 15 essential oil crops plus three plant hormones (methyl jasmonate, MJ; gibberellic acid, GA3; and salicylic acid, SA) as foliar spray for Scotch spearmint (Mentha × gracilis Sole). GA3 and Achillea millefolium extract decreased essential oil content. Hypericum perforatum extract increased α-pinene, whereas SA decreased it. H. perforatum extract increased β-pinene and sabinene concentrations relative to hormones but was not different from the control. H. perforatum also increased l-limonene, while SA and GA3 decreased myrcene and MJ and SA decreased l-limonene. Application of MJ and SA increased l-carvone concentration relative to the control and most other treatments. The sulfur concentration in plant extracts was positively correlated to β-caryophyllene. None of the residual distillation waters showed significant antimicrobial or antimalarial activity. The distillation waste water from essential oil crops may serve as a modifier for Scotch spearmint essential oil.     

The effects of onion and salt treatments on essential oil content and composition of Rosa damascena Mill

Due to the low oil content of Rosa damascena Mill., on one hand, and the wide spectrum of its application, on the other hand, it is desirable to find ways to increase the oil yield and also its quality. Therefore, in the present study the effects of chopped onion (1.0, 1.5, 2.0 and 4.0 g per 220 g of rose flower) and sodium chloride (11.0, 15.5, 22.0 and 30.0 g per 220 g of rose flower) which were added to rose flowers before distillation, were investigated on the quality and quantity of the oil. The quantity was measured as the ratio of oil to rose flower (w/w, %) and the quality was evaluated using the oil composition especially the content of monoterpene alcohols and hydrocarbons. Compared with corresponding control sample, treating with 1.5 g of chopped onion increased the oil content by 41% but it resulted in a lower quality; whereas in the presence of 1.0 g of onion, an increase of 30% and a decrease of 18% were observed in the percentage of monoterpene alcohols and hydrocarbons, respectively without any considerable change in the oil content. However, the effect of sodium chloride was somehow different from that of onion; such that in the optimal amount (22.0 g), the salt had no considerable effect on the quality but an increase of 21% in the oil yield.     

Comparative seasonal variation and chemical composition of essential oils from the leaves and stems of Schefflera heptaphylla using microwave-assisted and conventional hydrodistillation

Two different isolation techniques, microwave-assisted hydrodistillation (MAHD) and conventional hydrodistillation (HD), were used to extract the volatile constituents from the leaves and stems of Schefflera heptaphylla (L.) Frodin harvested during four different seasons, which were subsequently analyzed via gas chromatography with flame ionization detection and gas chromatography with mass spectrometry. MAHD is more advantageous than HD in terms of energy savings and extraction time (60 min vs. 180 min for MAHD vs. HD). Large variations in the composition among the different oils were observed. The seasonal changes in the percentages of the main constituents of the oils were irregular; this affected the quantity and composition of the oil. Oil yield was affected by the method of extraction and seasonal changes. It ranged from 0.11% to 0.27%, with the maximum amount of oil extracted from the leaves using MAHD in winter and the minimum from the stem oil extraction using HD in spring. The essential oil content varied significantly with the season. Sesquiterpene hydrocarbons constituted the major portion of the essential oils. Sesquiterpene hydrocarbons were highest in the leaf oil extraction by HD during winter (88.6%) and lowest in the stem oil extraction by HD during spring (56.3%). Microwave irradiation did not adversely affect the composition of the essential oils. MAHD, indeed, is a modern, green, and fast technology.     

Seed and oil yields of Moringa oleifera variety Periyakalum-1 introduced for oil production in four ecosystems of South America

Moringa oleifera Lam. is a member of Moringaceae family which grows throughout most of the tropics, and is native to sub-Himalayan tracts of north west India, Pakistan, Bangladesh and Afghanistan. Moringa seed concentrates 35-45% oil which is considered a great natural cosmetic emollient almost total natural absence of color and odor, and high oleic acid concentration (>73%). To assess their production potential in the Arid Chaco, The Yungas Tropical Forest, Tropical Lowland Forest, and in the Sub-Humid Chaco Ecosystems of South America, a comparative trial was undertaken to determine their seed yield and oil content. Arid Chaco Ecosystem: significant (P < 0.05) difference in seed yields among years were found, with 176.17 and 481.25 kg/tree recorded for 1- and 2-year-old trees, respectively. Sub-Humid Chaco Ecosystems: the difference in seed yield and oil percentage between years was significant (P < 0.05). Comparison between years showed significantly (P < 0.05) higher seed yields, and significantly (P < 0.05) lower oil percentage for the two years old trees, than for the one year old trees. The oil/tree content was significantly (P < 0.05) higher for two years old trees than for one-year-old trees. Yungas Tropical Forest Ecosystem: seed oil percentage was significant (P < 0.05) higher in one-year-old trees than in seeds of two years old trees. Overall: over the tree years, oil percentage was significantly (P < 0.05) higher for seeds produced at the Arid Chaco than at the Sub-Humid Chaco. The seed/tree yields and the oil/tree content were no significantly (P < 0.05) different among the three ecosystems. However, when oil percentage per tree and seed yield/tree were combined trees from Sub-Humid Chaco and from Yungas Tropical Forest yielded significantly (P < 0.05) higher oil content compared to that from Arid Chaco trees.     

Arthropod communities related to different mixtures of oil (Glycine max L. Merr.) and essential oil (Artemisia annua L.) crops

Plants can host many herbivores and their natural enemies during their growth cycles. For this reason, changes in the relative abundance of crop and weed plants in a monocropping system as well as different crop plants in an intercropping system may produce great bottom up impacts in the specific and functional structure of spontaneous communities of arthropods. The hypothesis of this study was that the combination of two contrasting species, soybean (Glycine max, Fabaceae, N₂ fixing plant) and annual wormwood (Artemisia annua, Asteraceae, VOCs plant), would be related to different spontaneous communities of arthropods depending on the proportion of each species, and this would favor crop biodiversity without compromising crop production. The objectives of the study were: (a) to analyze the differences of spontaneous communities of arthropods related to different soybean (S)-annual wormwood (W) mixtures, using standard crop management for S production in Argentina, (b) to determine S and W total biomass and W essential oil content and yield and, (c) to analyze the relationship between arthropod communities and crop productivity. Factorial field experiments with 3 replications were done during 2006 and 2007. S density was kept constant (40 plants m⁻²) and different W densities (plants m⁻²) were added. Treatments were pure S, S + 2W, S + 4W, S + 8W and pure W (8 plants m⁻²). Arthropods were sampled at soybean full flowering and were classified in functional groups as herbivores and non-herbivores. S and W total and relative biomass and W essential oil content and yield from leaves and inflorescences were estimated in reproductive stage. Arthropod morphospecies abundance and richness were determined for each treatment. Data were analyzed using uni (ANOVA) and multivariate (CCA) techniques. Arthropods belonging to 7 orders presented a total richness of 48 morphospecies in 2006 and 36 in 2007, while total abundance was 379 in 2006 and 318 in 2007. The proportion of non-herbivores was higher than the proportion of herbivores. Different arthropod communities were observed according to each treatment. No differences were found among treatments in S + W and S total biomass production, while W total biomass and essential oil yield were both different among treatments. Relative biomass production of S and W was the main explanatory variable related to the contrast of arthropod communities between pure annual wormwood (W) and the rest of the treatments. Annual wormwood could be used as an accompanying essential oil crop or left as a weed in the densities tested in this work, favoring biodiversity and, eventually, pest management without compromising soybean crop yield.     

The effects of harvest date,fermentation duration and Tween 20 treatment on essential oil content and composition of industrial oil rose (Rosa damascena Mill.)

The essential oil of Rosa damascena Mill. is one of the most valuable and important base material in the flavor and fragrance industry. The aim of this study was to determine the effects of harvest date, fermentation duration and Tween 20 treatment on the essential oil content and composition of the rose petals. The essential oil content and composition were significantly different in the petals harvested at various dates (May 24, June 1, 8, and 15, 2002). The highest oil content was found on May 24 harvest (0.040%), and then a gradual decrease was observed up to last harvest date (0.032%). The highest percentages of geraniol, nerol, and phenylethyl alcohol were obtained from the petals harvested on May 24. However, the highest percentages of citronellol and linalool were found from the petals harvested on June 8. The petals collected freshly were fermented for various duration (0, 12, 24, and 36 h) at 25 °C in sacks. The highest essential oil content was found in the non-fermented petals. As fermentation duration increased, essential oil content gradually decreased. The most significant changes during the fermentation were observed in citronellol and geraniol contents. Citronellol/geraniol (C/G) ratio increased from 0.57 to 10.31 throughout the fermentation. In the other experiment, Tween 20 was added into the distillation water at various concentrations (0, 1000, 2500, and 5000 ppm). Although Tween 20 generally raised the contents of essential oil, it did not significantly influence the oil composition. The highest oil content (0.045%) was obtained from the distillation treated with 2500 ppm of Tween 20. Oil content had high positive correlations with geraniol and linalool contents (r=0.55 and 0.53, respectively), but high negative correlation with citronellol content (r=−0.48).     

Highly efficient in vitro regeneration of the industrial oilseed crop Crambe abyssinica

A highly efficient regeneration protocol for oilseed crop Crambe abyssinica has been developed using hypocotyls as explants in this study. Crambe is a potential engineering oilseed crop for industrial purposes as it contains 55-60% erucic acid in its oil and, more importantly, it does not outcross with any food oil seed crops. However, the low regeneration frequency with the currently available protocols is still a limiting factor for genetic modification of Crambe. In this study, we investigated the effects of N-source, C-source, AgNO₃, cultural conditions as well as the concentration and combination of plant growth regulators (PGR) on the regeneration frequency of C. abyssinica. The results showed that all these factors, especially the N-source and PGR concentrations and combinations, played an important role in shoot regeneration. Among all the factors tested, the combination of using hypocotyls from C. abyssinica cv. galactica, the Lepiovre basal medium supplemented with 16 g l⁻¹ glucose, 0.5 g l⁻¹ AgNO₃, 2.2 mg l⁻¹ thidiazuron (TDZ), 0.5 mg l⁻¹ α-naphthaleneacetic acid (NAA), 2.5 g l⁻¹ Gelrite, seeds germinated in dark for 3 days and explants cultured in light, gave the best regeneration frequency (over 95%). The results also suggest that reducing the content of NH₄⁺ or keeping a suitable NO₃⁻/NH₄⁺ ratio in the regeneration medium would be crucial to Crambe shoot regeneration.     

Changes in phytochemical, antimicrobial and free radical scavenging activities of the Peruvian pepper tree (Schinus molle L.) as influenced by fruit maturation

The effect of stage of maturity on total lipids, fatty acids, yields and essential oil composition and their antimicrobial and free radical scavenging activities of the Schinus molle fruits was investigated. The content of total lipids varied from 2.87 to 5.35% (w/w, dw) and were rich in unsaturated fatty acids particularly linoleic acid. As maturation progress, the essential oil yield dropped from 5.18% to 1.15%. Monoterpene hydrocarbons with α-phellandrene (35.15-40.38%), limonene + β-phellandrene (21.47-36.62%), β-myrcene (7.61-24.96%) and α-pinene (1.92-2.58%) were found to be the main components. At the same time, the essential oils were evaluated for their antimicrobial and free radical scavenging activities. They were found to be active against Bacillus subtilis, Bacillus cereus, Salmonella typhymurium and Escherichia coli but they do not inhibit the growth of Candida albicans. Conversely, they showed very weak activity against the DPPH radical. In both assay, the oil derived from the intermediate stage was reported as more efficient.     

Toxicity of quinones against two-spotted spider mite and three species of aphids in laboratory and greenhouse conditions

Toxicities of the eight quinones were evaluated through leaf dip bioassays conducted against Tetranychus urticae, Myzus persicae, Myzocallis walshii, and Illinoia liriodendri. Based on LC₅₀ values, plumbagin (LC₅₀ = 0.001%) was the most active compound against T. urticae and ubiquinone Q₀ (LC₅₀ = 0.005%), plumbagin (LC₅₀ = 0.010%), and dibromothymoquinone (LC₅₀ = 0.012%) were the most active compounds against M. persicae. The most active compounds against M. walshii were juglone (LC₅₀ = 0.011%) and ubiquinone Q₀ (LC₅₀ = 0.019%), whereas dibromothymoquinone (LC₅₀ = 0.030%), plumbagin (LC₅₀ = 0.033%) and ubiquinone Q₀ (LC₅₀ = 0.058%) were the most toxic to I. liriodendri. Ecotrol (positive control) was the least toxic compound (LC₅₀ = 0.39%) against T. urticae and M. persicae (LC₅₀ = 0.447%). Although the majority of the compounds tested were toxic to all four test species in residual bioassays, there was little overlap among the test species in terms of susceptibility to the compounds and interspecific differences were observed. Regarding structure-activity relationships for quinones, the addition of a hydroxyl group resulted in a significant increase in the toxicity of the 1,4-naphthoquinones, and those possessing a methyl group exhibited the highest levels of activity in T. urticae. The bromine atom at the 2- and 5-positions of the benzoquinone ring is crucial to the toxicity of the compounds against I. liriodendri. Toxicity was greatly affected not only by the number of hydroxyl groups, but also by their positions in the ring in the case of M. walshii. Juglone and plumbagin as residual toxins in the laboratory also reduced the population of two-spotted spider mites compared to EcoTrol™ (positive control) and the negative control in the greenhouse experiment. Some quinones tested may have potential as commercial insecticides and miticides, or alternatively, could serve as lead compounds for the development of more potent crop protection agents.     

Optimization of nitrogen rate and seed density for safflower (Carthamus tinctorius L.) production under low-input farming conditions in temperate climate

Field experiments under low-input farming conditions were conducted in South West Germany (lhinger Hof) and North Switzerland (Wil) in 2004 and 2005 aimed at optimizing nitrogen rate and seed density for the production of the newly introduced safflower (Carthamus tinctorius L.). The experiments were laid out in a four-replicated-split plot design with three nitrogen fertilizer rates (0, 40, 80 kg/ha) as main plots and cultivars (Sabina, Saffire, BS-62915) and seed densities (50, 100, 150 seeds/rn2) randomized in split plots. It was shown that many traits responded differentially across environments to rate of nitrogen and seed density. Application of 40 and 80 kg N/ha did not significantly affect most of the investigated traits. At Ihinger Hof, the total nitrogen fertilizer needed to maximize safflower yield was estimated to be 86 kg N/ha. At Wil, residual soil nitrogen alone resulted in satisfactory seed yield when safflower followed a crop fertilized at a commercial rate. The nitrogen rate × seed density interaction was only significant for seed yield and Alternaria leaf spot disease. Nitrogen rates provided significant increases in seed yield at high seed density compared to low seed density. Seed density did not reveal any significant variation in seed yield, oil content, and oil yield. On average, the low seed density produced substantially higher numbers of heads/plant and seeds/plant compared to medium and high densities. These results demonstrate the ability of safflower to use residual soil nitrogen efficiently and to compensate for low plant density.     

Growing conditions and postharvest management can affect the essential oil of Origanum vulgare L. ssp. hirtum (Link) Ietswaart

Origanum vulgare subsp. hirtum (Link) Ietswaart (Greek oregano) has been cultivated since ancient times thanks to its herbal and therapeutic properties. Currently, it is added in various commercial preparations thanks to its essential oil composition. This group of secondary compounds is affected in quantity and quality by biotic and abiotic factors during the cultivating phase and by the postharvest management. Thus, the aims of the work were to study: (1) how the growing conditions (soil full-light treatment; pot full-light treatment; pot 50%-shade treatment) can affect the essential oil content and the essential oil profile of Greek oregano branches at full-blossoming stage; and (2) how the postharvest management (distillation of the essential oil from fresh herbs, dehumidified herbs or oven-dried herbs) can affect the essential oil content and the essential oil profile of this species. The growing conditions significantly affected the biometrical parameters. The pot full-light treatment contained the highest dry matter percentage (36.5%) and the highest essential oil content, which was directly correlated to the former parameter (r = 0.890**). The postharvest management did not affect the essential oil content. The growing condition significantly affected the characterizing γ-terpinene, cis-sabinene hydrate, 4-terpineol, α-terpinene, linalyl acetate, and β-bisabolene, while it did not affect carvacrol (mean value 15.8%), p-cymene (mean value 6.0%), or sabinene (mean value 3.9%). The postharvest management significantly affected carvacrol, cis-sabinene hydrate, 4-terpineol, p-cymene, α-terpinene, linalyl acetate, and β-bisabolene, while it did not affect γ-terpinene (mean value 14.7%). The response of some compounds to growing conditions led us to hypothesise an essential oil profile of the plants grown in pots at 50%-shade to be more of a vegetative stage type oil than the essential oil profile of the plants grown in soil, although all were at the blossoming stage. The analyses on the individual compounds indicated that, even though the essential oil content in oregano did not change with a change in postharvest management, biochemical changes occurred on the profile. These could be due to enzyme activity, dilution effect or temperature effect during the drying processes. The oven-drying process and the dehumidifying process changed the essential oil profile in a similar way compared to the essential oil profile distilled from fresh herbs. Thus, when it is not possible to extract the essential oil directly from fresh herbs, processors can dry the oregano according to the equipments they have available.     

Ultrasound-assisted extraction and profile characteristics of seed oil from Isatis indigotica Fort

In order to further exploit the by-products of Isatis indigotica Fort., the seed oil was studied for its extraction and physicochemical properties. Ultrasound-assisted extraction (UAE) was used, and the parameters affecting seed oil recovery were optimized through response surface methodology (RSM). The optimum conditions were as follows: solvent-to-sample, 24:1; particle size, 110 meshes; extraction temperature, 49 °C; and extraction time, 44 min. Which resulted in a maximum oil recovery of 81.20 ± 0.21% (n = 3). Furthermore, the effects of UAE on the yield, fatty acid compositions, physicochemical properties, and microstructure of the seed powder were also investigated by calculating the recovery rate, utilizing a gas chromatograph fitted with a mass spectrometer (GC-MS), and performing scanning electron microscopy, respectively. The results show that UAE was an effective method for the seed oil extraction and the high content of unsaturated fatty acids (93.81%) demonstrates the oil has potential benefits for the cosmetics, edible products, or pharmaceutical industries.     

Root lodging in sunflower. Variations in anchorage strength across genotypes,soil types,crop population densities and crop developmental stages

Root lodging is an important adversity affecting sunflower (Helianthus annuus L.) production in Argentina under current husbandry practices, and may limit progress towards the achievement of higher yields via increased plant population density. Although there are perceptions that lodging susceptibility varies across developmental stages, crop population densities, genotypes and soil types, these perceptions have not been tested for sunflower using a standardized experimental protocol. This study aimed at: (1) identifying the sources of the variation in root lodging susceptibility in response to variations in crop population density in two genotypes of reputedly different susceptibility; (2) detecting the crop developmental stages most susceptible to root lodging; and (3) examining the relationships between root failure moment, root plate diameter and soil shear strength. We mechanically induced lodging at three developmental stages in plants rooted in pre-wetted plots. The crops were grown at 5.6 plants m⁻² over 3 years on either Typic Argiudoll or Typic Hapludoll soils and at 3, 5.6, 10 and 16 plants m⁻² on a Typic Argiudoll. The force needed to induce root lodging (root failure moment) and root plate diameter varied across genotypes, plant densities and developmental stages. Root failure moment and root plate diameters were greater (p < 0.05 for both variables) in the resistant hybrid across the three development stages and almost all crop population densities. For both hybrids, the most susceptible development stage was R2, and root failure moment and root plate diameter diminished (p < 0.05) as crop population density increased. Although root failure moment did not differ between soil types, root plate diameter was greater (p < 0.0001) in the coarser soil. The relationship between root failure moment and the product of root plate diameter cubed by soil shear strength (a measure of plant anchorage strength) for both hybrids, both soil types, and all crop population densities could be described by a single linear relationship (y = 0.2382x; R² = 0.812; p < 0.025).     

Progress over 20 years of sunflower breeding in central Argentina

This paper applies linear mixed model analysis to 122 on-farm trials of commercial and near-commercial sunflower (Helianthus annuus L.) hybrids grown over 15 years in 32 locations of central Argentina to quantify increases in oil yield and to determine the contributions of change in both biotic stress resistance and yielding ability in favourable environments. The best linear unbiased predictors (BLUPs) from this analysis can be regarded as measures of ‘relative peak performance’ of hybrids in environments for which they were selected, and are a better measure of their adaptation compared to small trial sets of ‘historical’ hybrids. The BLUPs of 49 commercial hybrids released between 1983 and 2005 showed a genetic gain for oil yield of 11.9 kg ha⁻¹ yr⁻¹. Special purpose hybrids that were converted for single traits or that were developed for low-technology markets lagged by 5–15 years in terms of genetic gain. Genetic gains came about due to both an increase in the number of hybrids with resistance to the major biotic stress (Verticillium dahliae Klebahn) and a genetic gain in oil yield of 14.4 kg ha⁻¹ yr⁻¹ within these hybrids. Based on the data and the estimated time lag between commercial release and peak use, the improvement in oil and grain yield of conventional hybrids in central Argentina will be sustained until at least 2010, with evidence that the new germplasm pools still have substantial genetic variance to be exploited.