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Natasha Kovatcheva, Valtcho D. Zheljazkov and Tess Astatkie

species under the same ecological conditions have not been reported. The objective of this study was to compare the essential oil content, constituents, and morphologic/phenologic characteristics of 25 varieties, chemotypes, and hybrids belonging to the

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Valtcho D. Zheljazkov, Vasile Cerven, Charles L. Cantrell, Wayne M. Ebelhar and Thomas Horgan

harvested area of ≈32,076 ha ( USDA, NASS, Crop Report, 2007 ). The U.S. peppermint oil is considered of high quality and U.S. essential oil broker companies have dominated the peppermint essential oil market. The essential oil content and composition of

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Valtcho D. Zheljazkov, Tess Astatkie and Ekaterina Jeliazkova

, measured on analytical scale, and kept in a freezer at –5 °C until all distillations were finished. The essential oil content (yield) was calculated by weight, as grams of oil per 100 g of fresh herbage, and expressed as percentage of oil in the fresh

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Joyce W. Ngure, Chunyan Cheng, Shuqiong Yang, Qunfeng Lou, Ji Li, Chuntao Qian, Jie Chen and Jinfeng Chen

al., 2008 ). Genotype and environmental conditions affect oil content and fatty acid compositions in oilseed crops. Helianthus annuus seeds showed reduced oil and oleic acid quantity in autumn as compared with spring. However, palmatic and linoleic

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Valtcho D. Zheljazkov, Charles L. Cantrell, M. Wayne Ebelhar, Dennis E. Rowe and Christine Coker

( Hitsuda et al., 2005 ). Sweet basil requirement for S are unknown or have not been reported in the literature. The hypothesis to be evaluated in this study was that N and S rates would have a significant effect on sweet basil productivity and oil content

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Denys J. Charles and James E. Simon

Essential oils were extracted from leaves, flowers, and stems of Ocimum basilicurn, O. kilimandscharicum, and O. micranthum by solvent extraction, hydrodistillation, and steam distillation for essential oil content and the oil analyzed by GC and GC/MS for composition. While the yield of essential oil was consistently higher from steam distillation than hydrodistillation, a similar number of compounds was recovered from both hydrodistillation and steam distillation. Though the relative concentration of the major constituents was similar by both methods, the absolute amounts were higher with steam distillation. Essential oil content and composition varied by plant species and plant part. Essential oil content was highest in flowers for O. basilicum and in leaves for O. micranthum. No significant differences were observed in essential oil yield and relative concentration of major constituents using fresh or dry samples and using samples from 75 g to 10 g of dry plant tissue. While minor differences between hydrodistillation and steam distillation were observed, both methods resulted in high yields and good recovery of essential oil constituents. Hydrodistillation is a more-rapid and simpler technique than steam and permits the extraction of essential oil where steam is not accessible.

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Ossama Kodad, José M. Alonso, María T. Espiau, Gloria Estopañán, Teresa Juan and Rafel Socias i Company

cultivars before being released ( Socias i Company et al., 2008 ). Recent studies on the transmission and heritability of oil content, fatty acid composition, and the different tocopherol homologs ( Font i Forcada et al., 2011 ) have shown that oil content

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Carmen del Río and Ana M Romero

Several experiments showed that whole, unmilled olives (Olea europaea L.) could be dehydrated in 42 hours in a forced-air oven at 105 °C (221 °F), so that they could be used in determining their oil content in a nuclear magnetic resonance (NMR) analyzer. After confirming that the NMR and the official Soxhlet methods estimate the same oil percentages in milled olives, linear regression analysis also showed that NMR provides the same oil percentage results with milled and unmilled fruit. This new method avoids sample manipulation before dehydrating the fruit, making it possible to work with olive samples weighing as little as 70 g (2.47 oz). It allows for processing a large number of samples in a short period of time and may be also used with unmilled fruit flesh. The method is also very useful for screening genotypes, either from germplasm banks or progenies from olive breeding programs, and for evaluating cultivars in comparative trials.

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Thomas H. Boyle, Lyle E. Craker and James E. Simon

Plants of rosemary [Rosmarinus officinalis L. (Lamiaceae)] were grown in pots containing a soilless (1 sphagnum peat:1 perlite) or soil-based (1 sphagnum peat: 1 perlite:1 field soil) growing medium and fertilized with either 12N-5.2P-12.5K controlled-release fertilizer (CRF) at 9.0 g/pot; constant liquid fertilization (LF) with 20N4.3P-16.7K at 150 mg N/liter; constant LF at 150 mg N/liter, plus CRF at 4.5 g/pot; weekly LF at 150 mg N/liter; or weekly LF at 150 mg N/liter, plus CRF at 4.5 g/pot. Constant LF plus CRF generally reduced plant height and depressed shoot fresh weight relative to other fertilizer regimes. Essential oil content was highest in plants receiving weekly LF. Plants grown in the soil-based mix were shorter, shoot fresh and dry weight tended to be lower, and essential oil yield was higher when compared to plants grown in the soilless mix. Satisfactory growth was obtained in both media when rosemary plants were fertilized with 12N-5.2P-12.5K CRF at 9.0 g/pot or weekly LF with 20N<.3P-16.7K at 150 mg N/liter.

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Ashraf Abdallah, Miguel H. Ahumada and Thomas M. Gradziel

Seed of California almond [Prunus dulcis (Mill.) D.A. Webb, syn. P. amygdalus Batsch, and P. communis (L.) Arcangeli, non-Huds.] genotypes contained very low saturated fatty acids, high monounsaturated fatty acids, and low polyunsaturated fatty acids. Kernel oil consisted primarily of five fatty acids: palmetic, palmetoleic, stearic, oleic, and linoleic. Linolenic acid was only present in amounts of <0.02% and only in a few samples. Small but significant differences among genotypes and sampling sites were found in the proportions of palmetic, palmetoleic, and stearic fatty acids. The major differences in fatty acid composition among genotypes was found in the proportions of oleic, a monounsaturated fatty acid, and linoleic, a polyunsaturated fatty acid. The proportion of oleic acid was highest, ranging from ≈62% to 76%, and was highly and negatively correlated with linoleic acid levels. Usable genetic variation and a significant genotype × environment interaction were identified for oil content and composition. The introgression of new germplasm from peach and related species does not appear to reduce oil quantity or quality, and may offer opportunities for further genetic improvement of kernel oil composition.