Essential Oil Yield Research Articles

Biostimulants Improve Plant Performance of Rosemary Growth in Agricultural Organic System

Rosemary (Rosmarinus officinalis L.) is an evergreen and a xerophytic shrub that is frequently employed in culinary, decorative, and industrial applications. It shows significant variations in biomass and essential oil (EO) yield due to effects of biotic and abiotic factors. Biostimulants are widely used in agriculture, and in organic agricultural systems, they may contribute significantly to the stability and/or to the increase in crop yields, ensuring respect for the environment. The aim of this study was to assess the effect of different types of biostimulants on the yield performance of rosemary. Four commercial formulations of biostimulants based on Eklonia maxima, Ascophyllum nodosum, fulvic acids, and protein hydrolysates were used for the tests. Water was used as a control. Six applications were performed. At harvest, several morphological and productive parameters were determined. All parameters were affected by biostimulant application. The highest fresh and dry yields were obtained with the application of fulvic acids (13.1 t ha−1 of fresh biomass and 4.3 t ha−1 of dry biomass) and protein hydrolysates (13.6 t ha−1 of fresh biomass and 4.4 t ha−1 of dry biomass) with values 60% higher than that of the control. Regarding the EO content in the dry biomass, the highest value (1.72% v/w) was found in control plants, whilst the lowest (1.14%) was observed in plants treated with fulvic acids. In the case of the EO yield, the lowest value (46.5 kg ha−1) per unit area was found in the control. The application of Eklonia maxima and protein hydrolysates produced the highest EO yield values, 65 kg ha−1 and 66.5 kg ha−1, respectively. This study highlights the use of biostimulants to increase the yield performance of rosemary when grown in an organic agricultural system.

Anatomy, ploidy level, and essential oil composition of <i>Hyssopus officinalis</i> ʻNikitskiy Beliyʼ <i>in vitro</i> and <i>ex situ</i>

Background. Clonal micropropagation is a biotechnological method for plant multiplication. The existing data on the structure of organs in vitro, genetic stability, and essential oil composition are limited for Hyssopus officinalis L., so this study was aimead at investigating these aspects under a short period of in vitro culturing.Materials and methods. Plants of Hyssopus officinalis ʻNikitskiy Beliyʼ cultivated ex situ, in vitro and ex vitro were analyzed. Conventional methods were applied to study plant anatomy, ploidy level, and relative DNA content, as well as to extract and analyze essential oil. Statistical analysis was performed using the Past 4.03 software.Results. According to the results obtained, with 6-BAP introduced into MS nutrient medium in optimal concentrations (0.3– 0.5 mg/L), the general in vitro structure of leaf blades in the developed microshoots was similar to those in ex situ plants, while the qualitative and quantitative changes observed were induced by the effect of specific culturing conditions and plant rejuvenation. The analysis of the ploidy level and relative DNA content in the nuclei isolated from the leaf tissue cells of the microshoots ex vitro after adaptation revealed no changes compared to the ex situ leaf parameters. The mass fraction of essential oil and its component composition in the mother plants and ex vitro regenerants were similar.Conclusion. Cultivation of Hyssopus officinalis ʻNikitskiy Beliyʼ microshoots on MS nutrient medium with 6-BAP optimal concentrations promotes morphogenesis without significant deviations in the ploidy level, relative DNA content, essential oil yield, or its component composition. The developed protocol for clonal micropropagation of Hyssopus officinalis ʻNikitskiy Beliyʼ provides clones identical to the ex situ plants.

Extraction, Chemical Composition and Insecticidal Activities of Lantana camara Linn. Leaf Essential Oils against Tribolium castaneum, Lasioderma serricorne and Callosobruchus chinensis.

Storage pests and the food spoilage they cause are problems of great concern. Using essential oil obtained from different plants as an insecticide against these storage pests can be considered an environmentally friendly pest management option. Lantana camara Linn. (family Verbenaceae) is a flowering species, and is also a noxious weed that can proliferate well in nearly all geographical habitats. A biopesticide derived from the essential oil extracted from this plant can offer an effective solution for controlling storage pests. The goal of this study is to extract and analyse the chemical composition of essential oil obtained from L. camara leaves, and assess its effectiveness as a bioactive substance against three storage pests: Tribolium castaneum, Lasioderma serricorne, and Callosobruchus chinensis. The yield of essential oil extracted from L. camara leaves was about 0.24 ± 0.014%. By employing the GC-MS technique, the major phytochemicals contained in L. camara leaf essential oil were identified as caryophyllene (69.96%), isoledene (12%), and ɑ-copaene (4.11%). The essential oil exhibited excellent fumigant toxicity (LC50 of 16.70 mg/L air for T. castaneum, 4.141 mg/L air for L. serricorne and 6.245 mg/L air for C. chinensis at 24 h), contact toxicity (LC50 of 8.93 mg/cm2 for T. castaneum, 4.82 mg/cm2 for L. serricorne and 6.24 mg/cm2 for C. chinensis after 24 h) along with effective repellent activity towards the test insects. In addition, the oil showed no significant phytotoxicity on the germination of paddy seeds. This presents the potential to utilize a weed in developing a biopesticide for effectively managing stored product insects because of its strong bioactivity.

Variety × Environment interactions for essential oil yield and cultivar recommendations of lemongrass in drought-prone areas

Lemongrass (Cymbopogon spp.), is a well-known aromatic grass distinguished by its unique lemon scent. The importance of lemongrass in gastronomic, pharmacological, and cosmetic uses is examined in this research paper. The chemical makeup of lemongrass is discussed, emphasizing the presence of citral and other bioactive chemicals that give the herb its flavor, aroma, and medicinal qualities. The study highlights the possible advantages of growing lemongrass in semi-arid areas like Lalitpur (U.P.) and Datia (M.P.) in the Indian state of Bundelkhand, since it may flourish there with little water and improve soil fertility. Five lemongrass varieties—Nima, Praman, CIMAP-Suwarna, Krishna, and CIM-Shikhar—are compared in the study according to their morphological traits, oil yield, herb yield, and citral content. Results demonstrate that the total citral content and essential oil output of the two kinds, LG1 and LG4, are constant between the two genotypes, LG3 and LG5, respectively, across the locations. Regarding the stable types, the location-specific recommendations for essential oil yield were LG1 and LG3, while LG2 and LG4 were suggested for the total citral content. With a few exceptions in the first and second locations, where some traits showed low to medium heritability, most traits in the different sites had broad-sense heritability that was generally high. In all three locations, there were substantial percentages of genetic advance over mean (GAM) for specific features. The retention of genotype stability depends on these characteristics. These cultivars possess advantageous characteristics for growing in the Bundelkhand area, potentially providing farmers with financial gains and improving land in semi-arid regions. The findings highlight the importance of lemongrass as a useful plant with a wide range of applications and aid in the selection of cultivars that are appropriate for a certain area.

Characterization of Larix decidua Mill. (Pinaceae) oleoresin's essential oils composition using GC-MS.

Larch oleoresin has been described regarding several biological activities and medicinal applications, such as wound healing and treatment of ulcers, but little is known about its chemical composition. Eight oleoresins from Larix decidua Mill. obtained from four companies and one adulterated control were therefore investigated to determine their content of essential oils and to verify possible differences in their composition in relation to the harvest and manufacturing processes. Essential oils (EOs) were isolated by distillation and the yield was analysed. The yield of EO varied among all samples. The yield of the pure larch samples covered a range of 7.8% to 15.5%. A higher yield (19.0%) was observed for adulterated control, which contained oleoresins from different Pinaceae trees. Age of samples had no impact on yield. However, there was a significant statistical variation (p<0.05) in the yields of the mid-summer oleoresins (>10%) compared to early or late summer (<10%), emphasising the importance of the time of collection. Samples were subsequently analysed by GC-MS. EO samples confirmed the presence of various chemical classes, such as monoterpenes, sesquiterpenes, and diterpenes. α-pinene was the compound with the highest concentrations (>50%), followed by β-pinene (>6%), D-limonene (>2.5%), α-terpineol (>0.9%), β-myrcene (>0.2%), and 3-carene (>0.05%). Samples were grouped using multivariate data analysis (MVDA) with respect to the chemical variation between the oleoresins' EOs. The resulting four clusters were named low (low yield obtained for the samples), mixed (mixed oleoresin from different Pinaceae species, adulteration control), old (old oleoresin kept in the institute), and normal (other oleoresins) samples, each presenting distinct chemical biomarkers. There were considerable differences between site and time of collection. Essential oil yield did not always meet requirements as defined by the German Homeopathic Pharmacopoeia. In addition, adulterated or aged samples could be identified as compared to pure and fresh larch oleoresins. We conclude that larch oleoresin used for pharmaceutical applications has to be carefully analysed and standardised to guarantee reproducible product quality.

Differential responses of genotype × environment interaction on Agronomic interventions affect the yield and quality of essential oil of interspecific basil hybrid of Ocimum basilicum L. × Ocimum kilimandscharicum

The investigations on interspecific hybrid basil were carried out in two distinct agro-climatic regions of India: Lucknow (Uttar Pradesh) and Rangareddy (Telangana). The experiment used an RCBD replicated thrice in each trial in each of the three seasons/environments: Jaid, Karief, and Rabi. The morphological and chemical changes of an interspecific basil hybrid/variety were studied across environments/seasons, and locations. All morphological traits and essential oil production are affected by the environment/seasons and location. The essential oil production and linalool concentration were found to be consistent. A high-quality linalool essential oil was discovered throughout the environment and locales. The biplot contrasted the test seasons/environments, as well as the researched locations and their interactions, visually. The ‘r' correlation between measured (M) and predicted (P) values was 0.998, and the predicted (P), means, and instability values (I) were all calculated using ATC coordinates. The ‘r' between GGE distance (GD) and entry means was also −0.952. This means that a higher absolute number indicates less stability, whereas a lower absolute value indicates a high level of stability. In summary, significant amounts of linalool-rich essential oil were obtained in the Northern Region (Lucknow) during the Jaid season (69.76 %) and the Southern Region (Hyderabad) during the Rabi season (69.88 %). This hybrid/variety's linalool content and essential oil yield averaged 190.78 kg/ha across seasons/environments and locations, with a linalool content of 67.91 %. Due to its high yield of top-notch linalool essential oil, the basil hybrid/variety that is particularly stable in terms of essential oil yield with high linalool content across seasons and places should be suggested for large-scale cultivation.

Chemical composition and antioxidant activity of black pepper (Piper nigrum L.) fructus essential oil hydrodistillation fractions

The aim of this study was to examine the effect of hydrodistillation time on the chemical composition and antioxidant activity of collected essential oils’ (EOs’) fractions from black pepper fructus for five hydrodistillation periods: I (0-15 min), II (15-30 min), III (30-60 min), IV(60-90 min) and V (90-120 min). In this way, an essential oil with the desired chemical composition and antioxidant activity can be selected. The essential oil was obtained by Clevenger-type hydrodistillation (CHD). The qualitative and quantitative composition of the collected EOs’ fractions was determined by GC-MS and GC-FID analysis. The efficiency of EOs’ fractions to scavenge DPPH radicals was evaluated spectrophotometrically. Essential oil yield was 3.0 ± 0.050 ml/100 g of plant material after 120 min of CHD. The content of monoterpene hydrocarbons and aromatic compounds decreased, while the content of oxygenated monoterpenes, sesquiterpene hydrocarbons and oxygenated sesquiterpenes increased with the time of CHD. The most abundant compound of EOs’ fractions was (E)-caryophyllene, whose content increased with the time of CHD (I-V: 24.9-36.6%). Results indicated that all collected EOs’ fractions exhibited antioxidant activity (EC50 values were in the range I-V: 81.27±0.327–8.02±0.044 mg/ml), where fraction V showed the highest activity. This study proved that CHD time and fractionation affect the composition and antioxidant activity of black pepper essential oil. Future research may be extended to examine other biological activities of black pepper EOs’ fractions, as well as synergistic effects of other identified active components of the essential oil, in addition to (E)-caryophyllene, that would affect biological activities.

Essential oil variation in Melissa officinalis L. cultivated under industrial field conditions: effects of different harvesting times and plant materials

Melissa officinalis L. is a cosmopolitan aromatic and medicinal plant from the Lamiaceae family, which is necessary for pharmaceutical and cosmetic production. To evaluate the impact of different harvesting times and plant materials on the essential oil content and composition of M. officinalis 4-year-old plants, the present study was conducted in Fars province, Iran, under industrial field conditions. A randomized factorial experiment with three replications was used. Each replication contained six treatments [3 harvesting of M. officinalis × 2 treatments (shade drying + fresh state)]. Hydrodistillation was used to obtain the essential oils from each treatment, which were subsequently analyzed using GC-FID and GC-MS. The results demonstrated a significant influence of harvesting times and plant materials on the essential oil content and composition of M. officinalis. The average essential oil content was 0.028% to 0.095% (w/w). At different harvest times, the fresh plant yielded a higher content of essential oil compared to the dry plant. The number of chemical constituents in the essential oils was influenced by different harvesting times and plant materials. The predominant and common constituents in all harvested plant materials were the oxygenated monoterpenes geranial (28.7-43.2%) and neral (12.9-30.9%). Based on the major compounds, the essential oils from different harvesting times and plant materials were categorized into two chemotypes: chemotype I (geranial/thymol) and chemotype II (geranial/neral). It is recommended that drying operations not be used as a post-harvest processing method to achieve the highest essential oil yield from M. officinalis.

Rendimento, composição e toxicidade de voláteis de piperáceas para insetos-praga

ABSTRACT The objective of this study was to investigate the influence of leaf drying techniques (bench and oven at 35 and 45 °C) on the essential oil (EO) yield of Piper aduncum L., Piper anonifolium Kunth, Piper crassinervium Kunth and Piper hispidinervum C. DC., and to analyze the chemical profile of EOs and the insecticidal potential of these oils against Ascia monuste orseis (Godart), Atta sexdens L., Zabrotes subfasciatus (Boheman), Cryptolestes ferrugineus (Stephens) and Sitophilus zeamais Motschulsky. EO yield was evaluated using four replicates of 100g of dry leaves. The EOs were obtained by hydrodistillation and subjected to GC-MS analysis to assess the chemical composition. Concentrations of 2.60 and 157.25 nL/cm2 were used in the oil toxicity bioassays. EO yield was higher in the species P. aduncum and P. hispidinervum using leaves dried in oven at 45 °C, with average yields of 4.72±0.04% and 2.61±0.26%, respectively. The major constituents present in the EOs of P. hispidinervum and P. aduncum were Safrole (98.80%) and Apiole (90.00%). For P. anonifolium, the major constituents were α-Muurolene (23.11%), y-Muurolene (16.60%) and Cadina-1(10), while for P. crassinervium, they were Viridiflorol (27.70%) and Sabinene (15.50%). It was found that the EOs of P. aduncum, P. anonifolium, P. crassinervium and P. hispidinervum had a toxic effect on insects, except for P. anonifolium and P. crassinervium for S. zeamais. EO yield was higher in the species P. aduncum and P. hispidinervum, and these oils caused a higher mortality rate for the investigated insects.

Factors influencing yield, chemical composition and efficacy of essential oils

Essential oils are secondary metabolites that are produced by plants for the purpose of protection from pests, predators, attraction of pollinators and seed dispersal. The oil is produced in different parts of the plants and contains various chemical compounds that give plants a characteristic odour and flavor. These compounds vary between different plant species and also within plants of the same species. The yield and the efficacy of essential oils also vary between and within species. The variations in the essential oil compounds, the yield and the efficacy is influenced by both exogenous and endogenous factors. Endogenous factors such as plant age, plant density, plant genotype, part of the plant where the oil is extracted brings about variability in yield, chemical composition and the efficacy of essential oils. Similarly, exogenous factors such as light intensity and temperature, water availability, altitude and latitude, soil type and composition, preparation of the plant material before the essential oil extraction, method of extraction of the essential oil and the storage conditions after extraction also have a great influence on the chemical composition, yield and efficacy of essential oils. The factors then need to be moderated in order to ensure that the essential oil produced is of the quality required. Once extraction is done, proper storage conditions to avoid oxidation is necessary as the essential oils await to be used. They should be stored in dark cool conditions in tightly closed dark glass containers to ensure long term quality. Knowledge on the growth requirements of the individual plants that produce oils is necessary so as to produce quality oil.

Water stress effect on the quality and quantity of lemongrass essential oils in glass greenhouses: Juvenile and adult stages

The detrimental effects of water stress on the survival and productivity of many medicinal and aromatic crops of pharmacological interest are becoming increasingly important given the socioeconomic issues involved. The scarcity of precipitation and its irregularity endanger the life and productivity of certain medicinal plants of pharmaceutical interest with high economic value. Indeed, the biosynthesis of essential oils is influenced by various environmental factors, namely, an increase in the intensity of water stress. This natural constraint could have a positive impact on the synthesis of essential oils as well as on their chemical composition. In this article, we propose the study of the impact of this abiotic constraint on the quality and quantity of essential oils at the juvenile and adult stages of lemongrass, known for its therapeutic effects, by gas chromatography (GC). This study revealed a reduction in the yield of essential oil from citronella depending on the increase in the intensity of water stress at the juvenile and adult stages, except at the adult stage for severe drying, with a significant increase in the αcitral of 27% for the moderate treatment for adult lemongrass, and the increase in the βcitral increased by 37% for the severe treatment for adult lemongrass compared to the controls.

Effect of biological protection of peppermint on productivity and yield of essential oils

Effect of biological protection of peppermint on productivity and yield of essential oils

Green manure (Crotalaria juncea L.) enhances Origanum vulgare L. biomass accumulation, essential oil yield, and phytochemical properties

Green manure (Crotalaria juncea L.) enhances Origanum vulgare L. biomass accumulation, essential oil yield, and phytochemical properties

Biochemical Characterization of Ethiopian Black Cumin (Nigella sativa L.).

Black cumin (Nigella sativa L.) seed oil has been used for its medicinal and aromatic values. Some studies revealed the presence of variability among N. sativa genotypes in seed oil content and yield. In Ethiopia, very few studies were conducted to investigate the variability of N. sativa genotypes by using biochemical traits. Thus, this study was conducted at Debre Zeit and Kulumsa Agricultural Research Centers' experimental sites under field conditions during the 2021 cropping season to investigate the variability of Ethiopian N. sativa genotypes based on biochemical traits. Sixty-four genotypes were used and arranged in an 8 × 8 simple lattice design with two replications. Essential oils (EOs) and fixed oils were extracted by the respective methods of hydro distillation and solvent extraction. The univariate, bivariate, and multivariate analyses of the collected data were performed. Combined analysis of variance (ANOVA) revealed significant differences among genotypes in fixed oil yield per hectare (FOY), EO content (EOC), and EO yield per hectare (EOY). EOY had a significant positive correlation with FOY and EOC. It is expected to improve all biochemical traits by 17.39%-94.62% over the improved varieties by selection of the top 5% landraces. Therefore, genotypes 90504, 219970, and 013_ATH were the top 5% best performed landraces by FOY and EOY over the improved varieties. So, through selection, it would also be possible to improve the studied biochemical traits of the genotypes. The principal component (PC) analysis (PCA) of four biochemical traits showed 85.86% of the total variance captured by the first two PCs. EOY and FOY were the main contributor traits to the variation in the first PC, whereas FOC and EOC were the main contributor traits to the variation in the second PC. The genotypes were grouped into three different clusters based on four biochemical traits with significant intercluster distance. This showed that there was sufficient diversity among the genotypes which can be exploited for the future N. sativa improvement program in Ethiopia.

Study on influence of distillation duration on yield and composition of turmeric leaf essential oil

Study on influence of distillation duration on yield and composition of turmeric leaf essential oil

CHEMICAL COMPOSITION OF EXTRACTS AND ESSENTIAL OILS OBTAINED FROM COMMON JUNIPER (JUNIPERUS COMMUNIS L.) IN AZERBAIJAN

Juniperus communis L. (common juniper) is a widespread plant species in the Western region of Azerbaijan. The dependence of the composition and content of various biologically active substances in juniper on natural climatic conditions was studied. The results of the study of the substances obtained from the extraction of leaves and branches in ethanol were presented. The composition of volatile compounds was studied by the gas chromatography technique. In all samples, monoterpene hydrocarbons always predominated with percentages higher than 70% (from 71.12% for the plant material collected in August to 74.38% for those in September), followed in similar quantities by oxygenated monoterpenes or sesquiterpene hydrocarbons with values between 10.45% and 12.77% and between 10.50% and 12.72%, respectively. Ascorbic acid content varying from 33.1 to 123.2 mg/100 g was also determined. The investigation of the yield of essential oils in different months of the year showed that its amount varies depending on the season (3.5-4.4% of the mass of dry raw materials).

Co-detection of eugenol and butylated hydroxyltoluene by green and selective hydrodistillation of Heliotropium europaeum L. using ionic liquids as additives

This study is the beginning of the research that focuses on uncon-ventional ionic liquids (ILs) hydrodistillation (HD) extraction of the essential oil of Heliotropium europaeum L. using ILs as additives. Two ILs based on 1- butyl-3-methylimidazolium were used by switching the anions (Cl- and PF6-). The effect of mass percent of the added ILs on its yield and composition was evaluated. Compared to the conventional HD, ILs-HD gives a higher yield of essential oils (0.10?0.36 %). Particularly, with [C4mim][PF6], the observation of morphological changes using scanning electron microscopy (SEM) con-firmed the effectiveness of the ionic liquid in this distillation process. The GC? ?MS analysis of essential oils (EOs) revealed the presence of sixty-six com-pounds in HD, ILs-HD methods. Gas chromatography?mass spectrometry ana-lysis of the EOs revealed the predominance of eugenol (1.70?72.35 %), but-ylated hydroxytoluene (8.95?65.39 %) and phytol (18.20 %). The new distil-lation methods of H. europaeum with ILs identifies more compounds (50 com-pounds in ILs-HD [C4mim][PF6]; 22 compounds in ILs-HD ([C4mim][Cl]) than conventional hydrodistillation (25 compounds in HD). Therefore, the ILs- -based hydrodistillation approach is superior in improving the production of EOs. It is important to emphasize that the data presented in this study are not yet available for any of this Algerian Heliotropium species of genus and present the great potential of this medicinal plant as a source of novel bioactive extracts with possible therapeutic uses.

Cytotoxic and Antioxidant Properties of Artemisia deserti Essential Oil Obtained by Different Extraction Methods

Background: Artemisia deserti Krasch belongs to Asteraceae family, and has many medicinal properties that used to treat a variety of diseases, including antihypertensive, invigorating blood circulation, antiallergy, antiviral, antitumor, and antioxidant. Methods: The objective of this study was the evaluation of cytotoxic and antioxidant activities as well as the chemical composition of A. deserti essential oil extracted by different extraction methods. These extraction methods included hydro-distillation (HD), salt-HD (Salt pretreatment followed by HD), maceration-HD (maceration pretreatment followed by HD), acid-HD (acid pretreatment followed by HD), ultrasound-HD (ultrasound pretreatment followed by HD), and enzyme-HD (enzyme pretreatment followed by HD). Results: The results revealed that the highest yield of essential oil was achieved by acid-HD (0.48% ± 0.11%). In all methods, the main compounds of essential oil were camphor (44.32%–66.80%), piperiton (14.11%–24.33%), and 1,8-cineole (4.85%–6.75%). The antioxidant property of essential oils was investigated using the DPPH method. Based on the results, the essential oils extracted by acid-HD and enzyme-HD methods had the highest property. The cytotoxic property of A. deserti essential oils was evaluated. The results demonstrated that the essential oil extracted by enzyme-HD indicated the highest cytotoxicity activity against human cervical carcinoma (HeLa) cells in both 24 and 48 h. Based on the gas chromatography-mass spectrometry results, 1,8-cineol, carvacrol, thymol, and myristicin were rich in the essential oil extracted by enzyme-HD, and the highest cytotoxicity activity of essential oil obtained by enzyme-HD method is probably related to these compounds. Conclusion: In addition, it was observed that enzyme-HD is an effective method in the extraction of essential oil with the highest antioxidant and cytotoxic activities.

Prediction of essential oil content in C. sintoc Leaves based on the direction of vegetation slope in Mount Ciremai National Park using ANFIS Artificial Neural Network.

C. sintoc is a plant that has a high essential oil content. Essential oils have many health benefits. Mount Ciremai National Park is an area that has abundant vegetation, especially C. sintoc. The purpose of this study was to predict the volume of oil contained in the leaves of C. sintoc based on its growing location in Mount Ciremai National Park (TNGC), West Java. Sampling was carried out in two stages, namely field samples and laboratory samples. Field samples with a single plot measuring 20 x 20 meters. Extraction of laboratory samples by steam distillation method. Data analysis using ANFIS method to predict the volume of essential oil. The results showed that the volume of essential oil in the leaves was largest on the western slope (1,96 ml), northern slope (2,01 ml), eastern slope (1,55 ml) and southern slope (1,37 ml) while the essential oil yield of extract oil in the leaves is found on the western slope (0,08%), northern slope (0,07 %), eastern slope (0,06 %) and southern slope (0,04), On the western slope (1,82 ml), northern slope (1,73 ml). The ANFIS analysis results showed a prediction accuracy of 90,99% with the highest tree productivity when C. sintoc BL grows at an altitude of 650-700 meters above sea level, tree diameter of 42 cm, height of 12 m, growing on sand-textured land and at a humidity of 75 and at a growing temperature range of 25-270C. The value of essential oil production volume is influenced by each variable such as tree diameter, tree height, soil texture, altitude, temperature and humidity.

Clinopodium menthifolium subsp. menthifolium in the Central Balkan Peninsula - essential oil composition in relation to climatic conditions

The compositional dependency of the essential oil of Clinopodium menthifolium subsp. menthifolium (Lamiaceae) on ecological conditions has not yet been investigated. In pursuit of this objective, we assessed the quantity and quality of the essential oil in plants from 11 natural populations from the Central Balkans and one cultivated plant. In order to determine the correlations between essential oil variations and environmental conditions, each habitat was characterised by 36 climatic and 19 bioclimatic parameters. Despite inhabiting diverse climatic zones, altitudes, and biogeographical regions, no significant differences were observed in the yield and qualitative and quantitative composition of the essential oils among the analysed plants. All the samples exhibited essential oil yield ? 0.5%, V/w, with piperitone epoxide as the major compound. Among the identified compounds, only limonene and (E)-caryophyllene demonstrated dependence on bioclimatic parameters. The bioclimatic parameters which influence the presence of a larger number of compounds are annual temperature range and the precipitation of the wettest quarter. The consistent quantity and quality of the essential oils of C. menthifolium subsp. menthifolium indicate their probable adaptive significance and could serve as chemotaxonomic features of this taxon.