Potential uses for cuphea oil processing byproducts and processed oils

Cuphea spp. have seeds that contain high levels of medium chain fatty acids and have the potential to be commercially cultivated. In the course of processing and refining cuphea oil a number of byproducts are generated. Developing commercial uses for these byproducts would improve the economics of growing cuphea. Oil fractions and byproducts were obtained from processed seeds of cuphea germplasm line PSR 23 (Cuphea viscosissima × Cuphea lanceolata). We investigated the employment of oil byproducts as growth regulators and solid residues as organic soil amendments on Calabrese broccoli (Brassica oleracea L, family Brassicaceae) seedling growth. Seed processing solid residue fractions, included presscake, bin trash, stem trash and seed trash. These fractions were ground and mixed into soil to obtain concentrations of 0, 0.5, 1, 3, and 10% (w/w). Ground presscake and bin trash could be employed as an organic soil amendment up to 1% without detrimental effects on broccoli. Ground seed meal (seed trash) was detrimental to seedling growth at all concentrations tested. Stem trash employed at 1% caused fresh and dry weights to increase 26.8 and 29.8%, respectively, compared to untreated broccoli seedlings. Stem trash could be employed up to 10% without a detrimental effect on broccoli seedlings. Solvent extraction to remove residual oils from residue fractions was also conducted to generate improved soil amendments. Generally, solvent extraction of seed-processing residue fractions improved the broccoli seedling growth responses. Administration of processed oils and their byproduct fractions as foliar sprays on broccoli seedlings was conducted at rates of 0, 10, 30, and 50 g L⁻¹. Plants were evaluated 72 h after spraying. Refined and crude oils had no effect on broccoli seedlings; gums and soapstock sprays had no effect at 10 or 30 g L⁻¹ concentrations but at 50 g L⁻¹ it killed seedlings. Distilled fatty acid fraction sprays killed broccoli seedlings at all tested concentrations. Certain oil byproduct fractions from cuphea oil processing can be employed as “environmentally-friendly” herbicidal sprays. Calorific evaluation of cuphea ag-wastes were conducted and found to compare well to other biomass energy sources.     

Physiological changes during seed development of cuphea

Cuphea (Cuphea viscosissima Jacq. x C. lanceolata W.T. Aiton, PSR23) is a new oilseed being developed in the north-central USA. Cuphea oil is high in medium-chain fatty acids suitable for detergent/cleaner applications and has potential for use in cosmetics. The objectives of this study were to determine the effect of seed development on seed moisture, weight, oil content, fatty acid composition, germination, and vigor. Two thousand cuphea flowers were tagged at anthesis in the field each year at Prosper, ND, in 2004, 2005, and 2006. Each flower that developed into a seed capsule was tagged and labeled with the date of anthesis. Two hundred developed capsules from the labeled flowers were harvested at 3 to 4-day intervals from 5- to 35 days post anthesis corresponding with 37 to 295 growing degree days (GDD). The GDD were calculated using a base temperature of 10 °C. Seed development required approximately 253 GDD or 30 days post anthesis to reach physiological maturity. Maximum seed germination was reached at 33 days post anthesis. Seed oil content increased and oil composition changed as seed matured. Seed oil was high in linoleic and palmitic acids from 0 to 10 days post anthesis and declined thereafter while capric acid began to accumulate at 10 days post anthesis and reached above 70% at physiological maturity.     

Differential sensitivity to temperature of cuphea vegetative and reproductive growth

Cuphea (Cuphea viscosissima Jacq. x C. lanceolata W.T. Aiton; PSR23) is a new oilseed crop rich in medium-chain fatty acids similar to tropical palms. Agronomic studies suggest that temperature is a key determinant of cuphea seed yields. However, little is known about the growth and photosynthesis response of cuphea to temperature. The following study is the first of its kind to evaluate cuphea's growth and photosynthesis response to temperature. Cuphea was grown under day/night temperature regimes of 18/12, 24/18, and 30/24 °C and regression analysis was used to assess its responses of growth and photosynthesis and determine their optimum temperature range. Vegetative growth and leaf photosynthesis adapted well over the temperature range studied. However, reproductive growth was more sensitive showing a decline with increasing temperature. Reproductive growth rate was greatest under the lowest (18/12 °C) temperature treatment and declined by 43% at the highest growth temperatures. In contrast, vegetative growth, which was greatest under the 24/18 °C treatment, declined by just 25 and 10% at the lowest and highest temperatures, respectively. Photosynthesis acclimated to temperature by up-regulation of in vivo Rubisco activity with declining growth temperature. Maximum Rubisco activity (V_cmax) in leaves under the 18/12 °C treatment was 76% greater than that of leaves grown at 30/24 °C. Photosynthetic acclimation permitted cuphea to vegetatively grow well over a wide temperature range, but does not explain the sensitivity of reproductive growth to temperature, which will require further research to elucidate.     

Seed physiological maturity in Cuphea

Cuphea (Cuphea viscosissima Jacq. × C. lanceolata f. silenoides W.T. Aiton, line PSR23) is a new crop being developed in the North Central United States, as an industrial oilseed crop. Cuphea PSR23 seed oil is rich in medium-chain-length fatty acids such as capric acid used to manufacture soaps and detergents. The objective of this research was to determine the time when physiological maturity of cuphea seed is reached and how seed development affects seed moisture, weight, oil content, fatty acid content, germination, and seedling vigor. To evaluate seed development, 2000 cuphea flowers were tagged at anthesis in the field at Prosper, North Dakota in 2004 and 2005. Each flower was tagged when open and the position on the main stem or branch was recorded. Two hundred capsules from the tagged flowers were harvested at 3- to 4-d intervals from 5- to 48-d post anthesis (DPA). Seed weight increased as a function of growing degree days (GDD) and the days from anthesis. Physiological maturity occurred when maximum dry seed weight was attained. Seed weight increases followed the Gompertz function with a R² = 0.90 (2004) and R² = 0.95 (2005). All capsules, regardless of their position on the stem, followed the same growth function for seed weight. The maximum dry seed weight estimated by the Gompertz function was 3.61 for 2004 and 3.58 mg seed⁻¹ for 2005. Physiological maturity estimated with a quadratic function occurred at 38 DPA or 270 GDD in 2004. In 2005, physiological maturity occurred at 26 DPA or 265 GDD. As a visual indicator when the capsules split-open seeds inside that capsule are physiologically mature. Seed moisture decreased from 900 g kg⁻¹ at 37 GDD post anthesis to 450 g kg⁻¹ at 319 GDD post anthesis in 2004; however, in 2005 seed moisture decreased from 850 to 81 g kg⁻¹ at 293 GDD post anthesis. Seed germination increased as seed developed and it was 83% when harvested 234 GDD post anthesis. Oil content increased from 98 g kg⁻¹ at 37 GDD post anthesis to 279 g kg⁻¹ 319 GDD post anthesis. Fatty acid composition varied throughout seed development. Seed development for 111 GDD and greater had more than 66% of capric acid (10:0). Cuphea should be harvested after 265 GDD post anthesis when most capsules on the main stem are split-open, have attained maximum seed weight, germination, seedling vigor, and oil content.     

Seed germination response of cuphea to temperature

Cuphea (Cuphea viscosissima Jacq. × C. lanceolata W.T. Aiton; PSR23) is a potential new oilseed crop. Its oil is high in medium-chain fatty acids that are suitable for detergent/cleaner applications and also for cosmetics. The objective of this study was to determine the critical temperatures for cuphea seed germination. To determine the base, maximum, and optimum temperatures for seed germination, mature cuphea seeds were harvested from plants grown at Prosper, ND, in 2004, 2005, and 2006. Seeds were germinated on a temperature-gradient bar varying between 5 and 35 °C. Cumulative germination was calculated for each temperature treatment. Base temperature (T_b) and optimum temperature (T_o) were estimated from the third-order polynomial temperature-response functions for each year. In addition, germination rate per day was used in a linear model to estimate the base temperature below which germination rate was equal to zero (T_b), and the maximum temperature above which germination was equal to zero (T_m). The optimum temperature (T_o) was calculated as the intercept of sub-optimal and supra-optimal temperature-response functions. Through the third-order polynomial temperature-response functions and the sub-optimal/super-optimal intercept approaches, we were able to generate six estimates for each critical value. Estimates of the base temperature for cuphea seed germination ranged between 3.3 and 11 °C, with the most reliable estimates between 6 and 10 °C, similar to many warm-season crops such as corn (Zea mays L.) and sorghum (Sorghum bicolor L.). The optimum temperature for cuphea seed germination ranged between 18.5 and 24 °C with a mean value of 21 °C. The maximum temperature for seed germination ranged 33–38 °C. On this basis, a cuphea planting date after 20 May is recommended for east-central North Dakota.     

Importance of vanadium and nutrient ionic ratios on the development of hydroponically grown cuphea

Cuphea (Cuphea viscosissima × C. lanceolata ‘PSR 23’) seed contains oils that have industrial application. However, little is known regarding cuphea’s optimal mineral nutritional requirements or responses to inhibiting elements. Oil seed crops often need additional phosphorus (P) to achieve optimal economic yield. Vanadium (V), a commonly occurring soil constituent, interferes with plant P uptake and earlier work showed that V is a factor in lipid metabolism. Hydroponic culture was used to evaluate the relative effect of V on the development of cuphea. Relative root length, root surface area, root weight, and aerial dry weights decreased exponentially as the V concentration increased from 0 to 153 μM. In contrast to field observations of other crops, additions of MgSO₄ to increase the Mg:(Mg+Ca) ratio further decreased plant growth by as much 50% at V concentrations greater than 31 μM. Root length was decreased by about 50% of the control when the plant was grown in 153 μM V and relative root area and dry weight were decreased by ≥75%. Increases in V concentration sharply reduced secondary and higher order lateral branching. Reduction in root growth was accompanied by a general chlorotic appearance. The results suggest that readily available V in field situations will result in poor root growth and crop performance. Also, the interaction of V and MgSO₄, common in soils in the region, will lead to further reductions in yields in the field.     

Ultrahigh CO2 levels enhances cuphea growth and morphogenesis

Applications of ultrahigh CO₂ treatments accelerated cuphea (Cuphea viscosissima × C. lanceolata ‘PSR23’) growth and development and aided in seedling establishment. The growth (fresh weight) and morphogenesis (number of leaves and roots and seedling length) were determined in cuphea seedlings exposed to 350, 1500, 3000, 10,000, or 30,000 μmol mol⁻¹ CO₂ for 30 days under greenhouse conditions. Greater CO₂ levels, especially the ultrahigh levels (i.e. ≥3000 μmol mol⁻¹ CO₂) resulted in significantly higher (P ≤ 0.05) fresh weights, leaf numbers, root numbers, and seedling lengths compared to seedlings grown under ambient air (350 μmol mol⁻¹ CO₂). For example, cuphea ‘PSR23’ Morris heavy seedlings showed the greatest seedling fresh weight, leaf number, root number, and seedling length when supplemented with 10,000 μmol mol⁻¹ CO₂ increasing 607%, 184%, 784%, and 175%, respectively, when compared to seedlings grown without CO₂ enrichment.     

Emergence of cuphea seeds treated with different fungicides

Cuphea (Cuphea viscosissima Jacq. × C. lanceolata f. silenoides W.T. Aiton, Lythraceae) is an oilseed crop, with medium-chain fatty acids, being developed for the North Central United States for industrial applications in the manufacture of soaps and detergents. Seed germination and seedling emergence of cuphea is often low when compared to the commercial crops. Identification of seed treatments to optimize seedling emergence and stand establishment for cuphea are important for commercial production. The objective of this study was to determine the effect of several fungicide treatments on pure live seed emergence (PLSE) of cuphea. Pure live seed emergence is defined as total seedling emergence adjusted by the germination of the seed planted. Field experiments were conducted at Prosper, ND and Glyndon, MN, in 2005 and 2006. Previous crop rotations were soybean [Glycine max (L.) Merr.]/hard red spring wheat (Triticum aestivum L.), and soybean/hard red spring wheat/sugarbeet (Beta vulgaris var. saccharifera L.) at Prosper and Glyndon, respectively, for both years. The experimental design was a randomized complete block with six treatments and four replicates. Treatments were: no fungicide applied (check treatment), captan, mefenoxam, fludioxonil + mefenoxam, azoxystrobin, and azoxystrobin + mefenoxam. Plant stand was counted and PLSE was calculated 10 to 15 d after seeding at all locations by counting emerged seedlings in the center two-plot-rows and adjusting PLSE for germination. Greenhouse experiments were conducted with soil treatments (pasteurized and non-pasteurized) and the same fungicide seed treatments as the field experiment. Pure live seed emergence, vigor index, and percent of diseased seedlings were recorded. Plant stand and PLSE were significantly greater for the seed treatments that had mefenoxam at the Glyndon, MN, environments, in which the previous crop was sugarbeet. Soil treatment (pasteurization) increased PLSE and vigor index. All fungicide seed treatments improved PLSE and vigor index and reduced damping-off compared to the untreated check. Results suggest that seed treatments including mefenoxam would be beneficial for commercial cuphea production.     

Large scale cultivation of Cynara cardunculus L. for biomass production—A case study

Large scale cultivation of the cardoon Cynara cardunculus L. for biomass production was installed using common agricultural practices and machinery in a total of 77.4 ha in southern Portugal in a region characterized by very hot and dry summers. This species is a perennial with an annual growth cycle. Installation by sowing was successful in spite of the extreme drought that occurred during this first cycle (221 mm), and the plants developed well during the second cycle (with 556 mm rainfall) with a mean density of 27 thousand plants per ha. Aerial photographs showed that 45.8 ha of the field had over 50% of ground cover by cardoon plants. The observed differences in soil occupation could be explained by rock outcrops, soil heterogeneity and land topography. The field biomass yield was estimated at 7.5 t ha⁻¹ and the plants at harvest had on average 2.1 m height and 2.2 cm stalk diameter, with 5.3 capitula per plant. Stalks represented 59.1% of total dry biomass. The capitula contain small oil seeds with an average of 126 seeds per capitulum and weighing 32 g per 1000 seeds. The mean seed yield was 603 kg ha⁻¹. The results of this experiment confirm that Cynara crops are suitable for biomass production in Mediterranean regions and that large scale operation can be applied including whole plant harvest or field fractionation for seed recovery. Careful attention to cultural practices was deemed important for field homogeneity and production. The observed plant variation, namely in oil seed production, suggests potential improvements through breeding.     

Interactions of sunflower (Helianthus annuus) and sunflower broomrape (Orobanche cumana) as affected by sowing date,resource supply and infestation level

The holoparasitic weed Orobanche cumana (sunflower broomrape) constrains sunflower (Helianthus annuus) production in many countries. The development of efficient control strategies requires an understanding of the processes underlying the complex environment–host–parasite interrelations. Growth and development of O. cumana and sunflower were quantified under field conditions in southeastern Romania. Sunflower hybrid Florom 350 was sown at two dates, in plots infested with 0, 50, 200 and 1600 viable O. cumana seeds kg⁻¹ dry soil, under low-input (rainfed, low nitrogen supply) and high-input (irrigated, high nitrogen supply) conditions. Sunflower shoot biomass reached peak values of 760–1287 g m⁻² between the end of anthesis and physiological maturity. Seed yield varied from 221 to 446 g m⁻². Sunflower biomass and yield were affected by all experimental factors. Seed yield responded positively to delaying sowing from early April to late May as well as to irrigation and fertilisation, and negatively to O. cumana infestation. Yield reductions, which were a product of reduced seed number and size, amounted to 13%, 25% and 37% at parasite seed densities of 50, 200 and 1600 viable seeds kg⁻¹ soil, respectively. Maximum O. cumana attachment numbers, recorded in late-sown high-input crops in 2004, ranged from 11 m⁻² in plots with 50 parasite seeds kg⁻¹ soil to 188 m⁻² with 1600 seeds kg⁻¹ soil. Parasite attachment number was a function of crop sowing date, water and nutrient supply, seedbank density, and sunflower biomass and root length density, via mechanisms of parasite seed stimulation, host carrying capacity and intraspecific competition. Delayed sowing and improved water and nitrogen supply were associated with increases in parasite number that neutralised yield-boosting effects of irrigation and fertilisation at the highest infestation level. Sunflower shoot biomass was significantly reduced by O. cumana infection, with reductions affecting organs in the order head > stem > leaves. Most of the discrepancy between infected and non-infected plants was accounted for by O. cumana biomass. Parasites mainly acted as an extra sink for assimilates during sunflower generative growth and impaired host photosynthesis to a much lesser degree. Results suggest that similar mechanisms govern infection level and host–parasite biomass partitioning across different Orobanche–host systems.     

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.     

Tocochromanol content and composition in Jatropha curcas seeds

Physic nut (Jatropha curcas L.) is a promising seed oil source for biodiesel production. Natural antioxidants play a major role in maintaining oxidative stability of oils and they also have important food and industrial applications. Among them, tocochromanols are the most abundant in seeds. The objective of this research was to evaluate the variation for tocochromanol content and profile in a germplasm collection of 52 accessions of J. curcas. Seeds collected in two different periods, August and November of 2009, were analysed for tocochromanol content. Additionally, the dynamics of tocochromanol accumulation in developing seeds was studied. Total seed tocochromanol content averaged 307.2 mg kg⁻¹ in August and 303.7 mg kg⁻¹ in November, whereas total oil tocochromanol content averaged 507.4 mg kg⁻¹ in August and 500.8 mg kg⁻¹ in November. The tocochromanol fraction was made up of 15.4% gamma-tocopherol, 83.8% gamma-tocotrienol, and 0.8% delta-tocotrienol in August and 18.0% gamma-tocopherol, 80.4% gamma-tocotrienol, and 1.6% delta-tocotrienol in November. Genotype × environment effects were identified for tocochromanol content but not for the proportion of major tocochromanol homologues, which showed a high positive correlation between both environments. Developing seeds contained primarily alpha-tocopherol and gamma-tocopherol at early stages of development, with gamma-tocotrienol and delta-tocotrienol being practically undetectable. Gamma-tocotrienol content remained practically undetectable till 66 DAP and then increased pronouncedly to final levels of 177.1 mg kg⁻¹ (74.8% of the total tocochromanol content). The powerful antioxidant and health-promoting properties of gamma-tocotrienol encourages further studies on selection for the tocopherol/tocotrienol ratio in Jatropha and on the potential of tocochromanols as high added-value products derived from Jatropha seed oil production.     

Antifungal and antiaflatoxigenic efficacy of Caesulia axillaris Roxb. essential oil against fungi deteriorating some herbal raw materials, and its antioxidant activity

The study deals with evaluation of antifungal and antiaflatoxigenic Caesulia axillaris Roxb. essential oil (EO) against herbal raw materials deteriorating fungi and its free radical scavenging activity. During mycoflora analysis these herbal raw materials were found to be severely contaminated by different fungi and aflatoxins. A total of nine different fungal species were isolated from three herbal raw materials. Aspergillus flavus LHPtc was recorded as the highest aflatoxin B1 producing strain. EOs of some plants were tested for their fungitoxicity against the toxigenic strain A. flavus LHPtc, and C. axillaris EO was found as potent fungitoxicant. C. axillaris EO was chemically characterized through GC-MS analysis which depicted the presence of 18 compounds, dl-limonene and Euasarone being the major components. The EO exhibited broad spectrum of fungitoxicity against fungi causing postharvest deterioration of herbal raw materials. At 1.0 μl ml⁻¹ the oil showed complete inhibition of fungal growth and aflatoxin B₁ production was inhibited at 0.8 μl ml⁻¹. Free radical scavenging activity of the oil was also recorded by 2,2-diphenyl-1-picrylhydrazyl assay, and its IC₅₀ value was found 18 μl ml⁻¹. The safety limit of the EO was determined in terms of LD₅₀ on mice, which was 9166.6 μl kg⁻¹, suggesting its non mammalian toxicity. The EO of C. axillaris may be recommended as a plant based preservative in enhancement of shelf life of herbal raw materials by preventing their lipid peroxidation as well as biodeterioration due to fungal and aflatoxin contamination.     

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.     

Fuel properties of oil from genetically altered Cuphea viscosissima

A genetically altered plant strain (Cuphea viscosissima VS-320) was identified which produces an oil with elevated levels of medium- and short-chain triglycerides. Previous studies have suggested that such an oil may be appropriate for use as a substitute for diesel fuel without chemical conversion of component triglycerides to methyl esters. This oil is also of interest for other industrial applications. This paper discusses the oil composition of C. viscosissima VS-320 and presents the analysis of several important alternative fuel screening properties of this oil: dynamic viscosity for shear rates of 1.617–64.69 s⁻¹ at temperatures of 25–80°C, boiling point at atmospheric pressure, temperature dependence of vapor pressure (from 40 to 760 mmHg for the 300–400°C temperature range), and heat of vaporization (ΔH_v). These properties have been established as indicators of fuel performance and can be used for initial screening of possible diesel fuel substitutes. These properties are compared to those of diesel, biodiesel, and vegetable oils. Analysis of these properties suggests that further genetic development of this plant as a source of diesel fuel is warranted.     

Nitrogen applications modify seed and oil yields and fatty acid composition of winter mustard

Winter mustard (Brassica juncea L.) is not a common crop in the Southeastern United States. With increased interest in biodiesel production, there has been corresponding interest in mustard in this region. The objective of this study was to evaluate the effect of N fertilization (0, 50, 100, 150 kg N ha⁻¹) on productivity, oil content, and oil composition of winter mustard ‘Pacific Gold’ grown at three locations in Mississippi (Stoneville, and two locations at Verona, namely Verona silt loam (Verona-SL) and Verona clay (Verona-C)). Nitrogen did not affect oil content (percent oil). Seed and oil yields (kg ha⁻¹) increased with N application relative to the unfertilized control. At the Verona-C location, the concentration of oleic acid was higher in the 50 kg N ha⁻¹ treatment. At Stoneville, linolenic acid concentration was higher in the 150 kg N ha⁻¹ and lower in the 100 kg/N ha⁻¹ treatment, while it was not different in the other treatments. Overall, the yield of the fatty acids (FA) palmitic, palmitoleic, stearic, oleic, linoleic, linolenic, arachidic, eicosanoic, behenic, erucic, lignoceric, and nervonic acid increased with higher N rates (100 or 150 kg N/h). The highest yield of FA in the two Verona locations were achieved in the 100 kg N ha⁻¹, while greatest yield of FA at Stoneville was achieved in the highest N rate (150 kg N ha⁻¹). Means of mustard oil yields in our study in the higher fertility treatment ranged from 737 to 1094 kg ha⁻¹. This study demonstrated winter mustard production in Mississippi and possibly other areas in the Southeastern United States can be successful and could provide seed and oil yields comparable to yields from other production areas.     

Effect of nitrogen rates on yield and quality of fennel (Foeniculum vulgare Mill.) accessions

Nitrogen rates and plant genotypes effects yield and quality of medicinal plants therefore, this experiment was conducted in order to determine the effects of nitrogen rates on fennel accessions quality and quantity. The experimental design was a split plot with nitrogen rate (0, 40, 80, 120 and 160 Kg N ha⁻¹) as main and accession (Isfahan, Tehran, Yazd and EU11486) as sub plots and replicated four times. The experiment was conducted at the Isfahan University of Technology Experimental Station, Isfahan, Iran during 2008-2009. Plant height, number of umbel per plant, 1000seed weight, number of seeds per umbel, seed yield, seed essential oil yield, seed and foliage essential oil contents and seed ash, protein and fiber contents were measured. Nitrogen fertilization increased all measured traits, but reduced ash content. On average, the highest seed and foliage essential contents and seed essential yield were produced at 160 kg per N ha⁻¹ and EU11486 was a superior cultivar for these traits. However, there was an interaction between N rate and accession on all traits. Isfahan (11.65 kg ha⁻¹), EU11486 (38.26 kg ha⁻¹), Tehran (15.32 kg ha⁻¹) and Yazd (22.06 kg ha⁻¹) produced the highest seed essential oil yield under application of 160, 80, 160 and 120 kg N ha⁻¹, respectively. Foliage of the accessions contained 0.45-0.91% essential oil and seeds of accessions contained 17.6-18.2% protein and 8.9-9.4% ash suggesting that foliage of fennel also is a good source of essential oil and seeds of fennel are good sources of protein and minerals. The results showed that N fertilization and accession can affect yield and quality of fennel and accessions responded differently to N fertilization rates, thus selection among the accessions and N rates for better fennel production is possible.     

The effects of nitrogen and iron fertilization on growth,yield and fertilizer use efficiency of soybean in a Mediterranean-type soil

Poor seed yield of soybean in Mediterranean-type environments may result from insufficient iron (Fe) uptake and poor biological nitrogen (N) fixation due to high bicarbonate and pH in soils. This study was conducted to evaluate the effects of N and Fe fertilization on growth and yield of double cropped soybean (cv. SA 88, MG III) in a Mediterranean-type environment in Turkey during 2003 and 2004. The soil of the experimental plots was a Vertisol with 176 g CaCO₃ kg⁻¹ and pH 7.7 and 17 g organic matter kg⁻¹ soil. Soybean seeds were inoculated prior to planting with commercial peat inoculants. N fertilizer rates were 0, 40, 80, and 120 kg N ha⁻¹ of which half was applied before planting and the other half at full blooming stage (R2). Fe fertilizer rates were 0, 200 and 400 g Fe EDTA (5.5% Fe and 2% EDTA) ha⁻¹. It was sprayed as two equal portions at two trifoliate (V2) and at five trifoliate stages (V5). Plants were sampled at flower initiation (R1), at full pod (R4) and at full seed (R6) stages. Application of starter N increased biomass and leaf area index at R1 stage whereas Fe fertilization did not affect early growth parameters. N application continued to have a positive effect on growth parameters at later stages and on seed yield. Fe fertilization increased growth parameters at R4 and R6 stages, and final seed yield in both years. This study demonstrated an interactive effect of N and Fe fertilization on growth and yield of soybean in the soil having high bicarbonate and pH. There was a positive interaction between N and Fe at the N rates up to 80 kg N ha⁻¹. However, further increase in N rate produced a negative interaction. Fertilization of soybean with 80 kg N ha⁻¹ and 400 g Fe ha⁻¹ resulted in the highest seed yield in both years. We concluded that application of starter and top dressed N in combination with two split FeEDTA fertilization can be beneficial to improve early growth and final yield of inoculated soybean in Mediterranean-type soils.     

Narrow row spacing and high plant population to short height castor genotypes in two cropping seasons

Castor plant (Ricinus communis L.) produces a very important oil for chemical and biofuel industries. However, doubts remain about what the best plant arrangement is to obtain the maximum yield of seeds and oil from short height castor genotypes cultivated in higher plant population. This study evaluated two castor genotypes (FCA-PB and IAC 2028) in 5 plant arrangements (row spacing × in-row spacing): 0.90 m × 0.44 m (traditional), 0.90 m × 0.20 m, 0.75 m × 0.24 m, 0.60 × 0.30 m, and 0.45 m × 0.40 m, in spring-summer and fall-winter cropping seasons in Botucatu, São Paulo State, southeastern Brazil. The traditional plant arrangement comprised an initial plant population of 25,000 plants ha⁻¹, while the others comprised 55,000 plants ha⁻¹. The IAC 2028 genotype presented the greatest plant height, first raceme insertion height, basal stem diameter, number of fruits per raceme and 100 seed weight; however, seed yield and seed oil content were equal between genotypes. Wider stems and higher number of racemes per plant and fruits per raceme were observed with a 0.90 m × 0.44 m plant arrangement, but due to the lowest plant population (25,000 plants ha⁻¹) in this plant arrangement, the higher values of the yield components mentioned above did not result in higher yield. The higher plant population (55,000 plants ha⁻¹) by narrower row spacings (0.45 or 0.60 m) combination produced a higher castor seed yield. The effect of plant arrangement was more intense in the spring-summer cropping season.     

Oil productivity and composition of sunflower as a function of hybrid and planting date

Sunflower (Helianthus annuus L.) is a potential cash crop for the southeastern United States for production of cooking oil or biodiesel. Two years (2006 and 2007) of experiments were conducted at each of five locations in Mississippi to evaluate the effect of planting date (April 20, May 20, and June 20), and hybrid (DKF3875, DKF2990, DKF3510, DKF3901, PR63M80, PR62A91, PR63A21, PR63M91, and PR64H41) on seed yield, oil content, and oil composition of sunflower. Seed oil concentration varied from 25 to 47%. The oleic acid concentration in the oil was greater than 85% for DKF3510 and PR64H41, above 65% for PR63M80 and PR63M91, and intermediate for the other hybrids. Total saturated fatty acids (TSFA) concentration in the oil (the sum of palmitic, stearic, arachidic, behenic, and lignoceric acids) ranged from 6.3 to 13.0%, with DKF3510, PR63M91, and PR64H41 having lower concentration of TSFA than the other hybrids. Mean seed yields ranged from 997 to 2096 kg ha⁻¹ depending on location. Mean oil yields at the five locations ranged from 380 to 687 kg ha⁻¹, and calculated biodiesel production ranged from 304 to 550 kg ha⁻¹. Seed and oil yields in this study suggest sunflower in Mississippi should be planted by the last week of May. Later planting (20 June) may significantly decrease both seed and oil yields in the non-irrigated system in Mississippi and in other areas of the southeastern United States with similar environmental conditions.