Relationship between total phenolic, total flavonoid and oleuropein in different aged olive (Olea europaea l.) Cultivar leaves

Background: Olive leaves have recently gained attention owing to its antioxidant antibacterial, antifungal and anti-inflammatory effects. Bioactive contents of olive leaves differ according to cultivation area, ecological conditions, age of tree, agronomical practices, cultivar, leaf growth stage and other abiotic and biotic stress factors.Material and Method: In this study, Olea europaea L. cultivar (Kilis Yaglık) at different age grown in Kilis were examined. In this context, total phenolic content, total flavonoid content and oleuropein content of young and old tree leaves were determined.Results: Correlations between total phenolic, total flavonoid and oleuropein in young and old trees of Kilis Yaglık cv. were found to be significant with respect to the content of each other, cultivars and age under irrigated and non-irrigated conditions.Conclusion: In the current study, more phenolic compounds and oleuropein were determined in young trees of cv. Kilis Yaglık whereas the higher total amounts of flavonoids were obtained in old trees. There were positive strong-correlation in terms of total phenolic and oleuropein contents and positive-moderate correlation in relation to the total flavonoid content between old and young trees of cv. Kilis Yaglık.Key words: Olea europaea L., Oleuropein, Flavanol, Total Phenoli

A Systematic Review: Polyphenol Contents in Stressed-Olive Trees and Its Fruit Oil

Olive oil includes high amounts of phenols and polyphenols. Through health benefits to humans, the antioxidant role of polyphenols that contain more than two phenolic hydroxyl groups has been well proven. Of those polyphenols, oleuropein, hydroxytyrosol, catechin, chlorogenic acids, hesperidin, nobiletin, and isoflavones are major compounds. Along with the present study, (1) the uses and biological roles of polyphenols have not been limited to their physiological roles to human health; their physiological roles for plant and aromatic values for plant are also evaluated; (2) possible roles of major components in response to environmental stressors are discussed; (3) bibliometric analysis of studies concerned with polyphenols in olive fruit oil has been done to evaluate the research trends concerned with polyphenol in olive fruit oil, considering the main theme of the studies. The study is concluded with highlights, limitation, and future outlooks

RELATIONSHIP BETWEEN TOTAL PHENOLIC, TOTAL FLAVONOID AND OLEUROPEIN IN DIFFERENT AGED OLIVE (OLEA EUROPAEA L.) CULTIVAR LEAVES

Backround and objective: Olive leaves have recently gained attention owing to its antioxidant antibacterial, antifungal and anti-inflammatory effects. Bioactive contents of olive leaves differ according to cultivation area, ecological conditions, age of tree, agronomical practices, cultivar, leaf growth stage and other abiotic and biotic stress factors. Material and Method: In this study, Olea europaea L. cultivar (Kilis Yaglık) at different age grown in Kilis were examined. In this context, total phenolic content, total flavonoid content and oleuropein content of young and old tree leaves determined. Results: Correlations between total phenolic, total flavonoid and oleuropein in young and old trees of Kilis Yaglık cv. were found to be significant with respect to the content of each other, cultivars and age under irrigated and non-irrigated conditions. Conclusion: In the current study, more phenolic compounds and oleuropein were determined in young trees of cv. Kilis Yaglık whereas the higher total amounts of flavonoids were obtained in old trees. There were positive strong-correlation in terms of total phenolic and oleuropein contents and positive-moderate correlation in relation to the total flavonoid content between old and young trees of cv. Kilis Yaglık

Flavonoid Accumulation Behavior in Response to the Abiotic Stress: Can a Uniform Mechanism Be Illustrated for All Plants?

This review concentrates on two aspects of how total flavonoid content and individual flavonoid compounds change with the perception of environmental stress and the subsequent changes in those metabolites after post-harvest conditions are of the main points of the study. Hereby, along with this study, the flavonoid synthesis or their accumulation with their importance in plants and then in humans is briefly described. According to the literature cited herein, it seems that a universal mechanism concerned with flavonoid accumulation in response to the abiotic stress factors cannot be illustrated. Flavonoid accumulation exhibits different reactions to the different stressors. Flavonoid accumulation behavior not only varies depending on the developmental stage, species and even cultivars of the same species but also post-harvest processes

HERB YIELD AND CHEMICAL COMPOSITION OF BASIL (OCIMUM BASILICUM L) ESSENTIAL OIL IN RELATION TO THE DIFFERENT HARVEST PERIOD AND CULTIVATION CONDITIONS

Background: Ocimum basilicum L., commonly known as sweet basil, is an important aromatic plant cultivated in many parts of the world for its essential oil. Basil does not show natural distribution in Turkey but they are cultivated as medicinal, seasoning or oil plants especially in the western and southern Anatolia. In this study, introduction of new production patterns of green and purple basil into Rize province in the northern parts of Turkey is the main objective of the present study. In this context, herb yield and chemical composition (essential oil and its components) of green and purple basil plants grown under open field and underneath or between kiwi plantations were determined and compared. Materials and Methods: The experiments were arranged as a split plot design with three replications in May in 2010 and 2011 in open-field conditions and between kiwi plantations. Three harvests were done for each year. After each harvest, above ground parts were dried at 35 ºC and essential oils from aerial parts after each harvest were extracted using 30 g of dried material by hydro distillation (4 h) with Neo-Clevenger apparatus. The essential oil compositions were identified by GC-MS. Results: There were decline trends with respect to the plant height, fresh and dry herb yield in the second year. For both experimental years, the highest fresh and dry herb-yields were obtained in open-field conditions in green basil. There were no statistically significant differences in relation to essential oil yield in open-field conditions and kiwi plantations but the highest essential content was ascertained in open-field conditions for green basil. The major aroma constituents of basil were methyl cinnamate and linalool and the highest percentage was determined in open-field conditions for green basil. Conclusion: The lowest essential content obtained in open-field and between kiwi plantations for green and purple basil plants was even higher than the limit (%0.3) established by Turkish Standards Institution and total yield concerned with fresh and dry herb yield complied with the previously proposed literatures. Hence, basil cultivation underneath kiwi plantations may be implemented

Management of Weeds in Maize by Sequential or Individual Applications of Pre- and Post-Emergence Herbicides

Weeds impose serious problems in maize (corn) production, resulting in reduced crop yields and lower profits for farmers. The adverse effects of weeds have been attributed to the competition with maize plants for light, water, and nutrients, which can result in reduced growth and yield of the crop. In this context, effective weed management is important to minimize the negative impact of weeds on maize production. This can be achieved through a combination of cultural, mechanical, and chemical control methods. The use of pre-emergence and post-emergence herbicides as sequential or individual applications of these herbicides can be an effective way to manage weeds in maize. Two consecutive field experiments were conducted in 2019 and 2020 in order to determine the efficacy of sequential and individual applications of Dimethenamid-P + Terbuthylazine and Isoxaflutole + Thiencarbazone methyl + Cyprosulfamide as pre- emergence. On the other hand, Mesotrione + Nicosulfuron and Dicamba + Nicosulfuron were used as post-emergence herbicides. The effects of the herbicides were also assayed on corn yield and related parameters. In this regard, we designed the experiment in a randomized complete block design with four replications. Accordingly, the effect of the herbicides varied according to the active ingredients of the herbicide and the weed species. In addition, the effectiveness of herbicides varied according to the assessment times. The lowest effect was found on E. crus-galli, which was obtained from Mesotrione + Nicosulfuron (MN) (35%) plots. Other herbicides showed high efficacy (95–100%). Concerning values of both years, the highest cob length, cob diameter, 1000-grain weight, and plant height were obtained in weed-free control plots and the highest grain yield was obtained in the control plots with weed-free checks as 12.88 tons/ha and 12.37 tons/ha, respectively. The lowest corn grain yield was obtained in weedy control plots in both years. Our findings demonstrate that the combination of pre- and post- emergence herbicides in maize can be an effective way chemical weed control option

Liquid Leachate Produced from Vermicompost Effects on Some Agronomic Attributes and Secondary Metabolites of Sweet Basil (<i>Ocimum basilicum</i> L.) Exposed to Severe Water Stress Conditions

Water stress is one of the most critical threats to the growth and productivity of plants and is one of the most studied topics in agricultural sciences. In order to enhance the tolerance of plants to water stress conditions, synthetic fertilizers have been widely used in the field. However, due to their toxic effects, recent reports have focused on organic options. In this study, the effects of liquid vermicompost applications (25, 50, 75, and 100%) on the agronomic attributes, phenolic compounds, and essential oil compounds of basil plants exposed to drought stress conditions were investigated. Accordingly, water stress critically reduced the factors of plant height, plant fresh weight, root fresh weight, leaf length, and leaf diameter. On the other hand, vermicompost applications significantly affected all of the parameters considered, except the leaf length of well-watered basil plants. However, a two-way ANOVA analysis revealed that the interactions of water stress and vermicompost were significant on root length and root fresh weight. Regarding the essential oil compounds, the contents of humulene, anethol, eucalyptol, estragole, bisabolene, germacrene, and caryophyllene were quantified. Estragole was determined as a major component by 85–90%. The results revealed that the highest estragole content was determined in the 25% vermicompost + water stress, water stress, and control groups. Of the major phenolic compounds, caffeic acid decreased as a result of water stress conditions but increased with vermicompost treatments. The rosmarinic acid content increased during water stress conditions, attaining the highest content at 25% via the vermicompost and water stress interaction. In general, the 25% and 50% vermicompost applications increased the content of phenolic compounds in plants under either well-watered or stress conditions