Demand for its essential oil continues to grow on a global scale. The fact remains that harvesting at the right time of growth is critical to maximizing the rate of active ingredients found in the plant. Thus, in the current study, L. angustifolia plants were collected at various growth stages (pre-flowering, mid-flowering, and post-flowering) from Adana, Turkey in order to determine the most suitable harvest time for the highest amount of essential oils and its important compounds. The highest flower essential oil content (7.50 mL 100 g-1) was obtained at mid-flowering of the third year of plantation. The major compounds for L. angustifolia were linalyl acetate (25.63-31.63%), linalool (16.33-24.79%), nerol (8.83-13.43%), beta-farnesene (3.67-5.70%), β-cis-ocimene (1.76-8.14%), respectively. The obtained data have been inquired by principal components analysis (PCA), allowing differentiation of plantation ages and growth stages. Compared to the plantation ages, essential oil content and linalool content increased significantly in the third year of cultivation. As a result, the most suitable harvest time may be considered as mid-flowering in terms of essential oil content and in terms of high linalyl acetate and linalool content.

Black cumin has been used in many countries for the treatment of diseases such as cancer and diabetes, and for thousands of years as a spice, flavoring in products such as bread, and as a food preservative in pickles. Too much delay in the sowing of black cumin has a negative effect on plant growth. In order to determine the most suitable sowing dates for different black cumin genotypes, an experiment was conducted in the open-field conditions of the Eastern Mediterranean region of Türkiye at Çukurova University, for two years, in 2020 and 2021, in three different sowing dates (October 15th, November 01st, and November 15th) with three different black cumin genotypes (Çameli cultivar (G1), Adana population (G2) and Iraq population (G3)). The findings of this research demonstrated significant differences in the agronomic characteristics and overall quality of black cumin. The main components were p-cymene (51.45%-66.33%), trans-4-Methoxythujane (8.40%-11.90%), thymoquinone (0.11%-19.26%), γ-Terpinene (1.28%-9.09%), and limonene (2.93%-4.50%). The main fatty acids were determined as linoleic acid (53.97%-57.56%), oleic acid (20.98-26.40), and palmitic acid (13.73%-15.02%). Consequently, the low number of flowers and the high temperatures observed in May, along with the early spring frosts, negatively affected the fertilization of the flowers. The seed yield was adversely affected because some of the seeds could not mature.

Marigold is an annual herbaceous medicinal and aromatic plant, native to the Mediterranean region. Although marigold flowers have attracted considerable attention, the noteworthy characteristics of marigold seeds have often been overlooked. The industrial sector holds keen interest in marigold due to the presence of calendic acid in its seeds. Moreover, calendic acid exhibits promising anti-cancer properties, adding to the growing interest in the medicinal potential of this plant. In this study, a total of 31 marigold genotype seeds from fifteen different countries were used as experimental material. The observed seed oil content exhibited a range of values spanning from 6.00% to 20.33%, with a mean value of 11.59%. GC/MS analysis was conducted to evaluate the chemical variability associated with genotypic changes. Notably, the main fatty acids observed in the oil of these genotypes were α-calendic acid (ranging from 6.91% to 51.42%), linoleic acid (ranging from 30.50% to 48.25%), oleic acid (ranging from 8.26% to 22.50%), and palmitic acid (ranging from 3.86% to 9.28%). Particularly noteworthy is the emergence of genotypes PI 420376, PI 545694, PI 545701, PI 578109, PI 597588, PI 597591, and PI 597594, boasting calendic acid content exceeding 50%. Furthermore, the values of calendic acid exhibit significant variation across countries. The range extends from the United Kingdom, displaying one of the lower values, to Ontario, Canada, which represents countries with notably higher values. Consequently, there exists a necessity to enhance the proportion of calendic acid within marigold through strategic plant breeding techniques. This can be achieved through the selection and development of marigold cultivars with higher calendic acid contents.

Rosemary is an aromatic shrub native to the coasts of the Mediterranean region. Understanding the changes of chemical composition of essential oil is critical for more targeted rosemary harvesting, which can lead to higher-quality essential oils for agro-food, medicinal, and cosmetics uses. Therefore, rosemary plants were harvested at pre-flowering, full-flowering, and post-flowering stage grown in the experimental area of the Department of Field Crops at Çukurova University in order to determine the most suitable harvest time for the highest amount of essential oils and their important compounds. Essential oil content decreased slightly from the pre-flowering to post-flowering. The highest essential oil content (1.68%) was determined at the pre-flowering stage. Twenty-eight compounds were found representing 95.74%-96.74% of the total essential oil. The major compounds for rosemary were camphor (28.43%-32.74%), 1,8-cineol (20.80%-22.61%), isoborneol (6.05%-7.28%), verbenol (5.17%-6.98%), and limonene (5.71%-6.23%), respectively. Consequently, the optimal harvest time in terms of essential oil content, as well as camphor, 1,8-cineole and limonene content, may be considered as pre-flowering stage.

Crambe is an annual or perennial plant belonging to the Brassicaceae (Cruciferae) family. The interest in Crambe is mainly due to its unique fatty acid profile, low input management and broad adaptability to the environment. Thus, Crambe seeds and fruit fatty acid compounds were investigated by GC / MS in order to examine the chemical variability which correlates with the environmental variability. In the study, Crambe orientalis var. orientalis and Crambe tataria var. tataria were used and they were collected from the different areas of three provinces of Turkey. Fifteen compounds were found, representing 90.24-100% of the total seed and fruit oils. The major components based on the location in both species were erucic acid (24.67-44.68%), gondoic acid (18.97-28.33%), oleic acid (14.92-28.46%), and linoleic acid (8.13-17.56%). The fatty acids in seeds and fruits were found to be similar. As a consequence, it is needed to increase the production of erucic acid (C22:1) and gondoic acid (C20:1) in Crambe by using wild populations via plant breeding and these two promising fatty acids may be an alternative to meet industrial fatty acid market demand in a more environmentally friendly way compared to using fatty acids from fossil oil.

This study was carried out to determine the effects of different varieties (Pot Marigold and Orange King) and planting times (March 15, April 1 and April 15) on the yield and quality of flowers and seeds of Calendula (Calen-dula officinalis) plant in the 2020-2021 growing seasons in Çukurova conditions. The experiment was set up in a split plot randomized complete block design with 3 replications. According to the data, the highest dry flower yield (360.63 kg/ha, March 15, 2021) was obtained from Pot Marigold variety, the highest fresh flower yield (1308.67 kg/da, March 15, 2020), flower essential oil (0.05 %, 15 March 2021) was obtained from Orange King variety. Highest seed yield 35.6 kg/da from balloon smooth shaped, highest seed fixed oil 15.39 % from balloon smooth shaped, was obtained. The maincomponent in flower essential oil was α-cadinol and in seed oil it as identified as calendic acid (α+β). Both varieties exhibit similar trends in terms of essential oils for use in commercial medicinal and food industries, while the Pot Marigold variety stands out in terms of dry flower yield, seed yield, and seed oil.