Effects of Sage Leafhopper Feeding Damage on Herbage Colour, Essential Oil Content and Compositions of Turkish and Greek Oregano

Abstract

SUMMARYTurkish (Origanum onites L.) and Greek oregano (Origanum vulgare L., ssp. hirtum (Link.) Ietswaart) species were investigated to determine herbage colour, essential oil content and composition changes due to sage leafhopper (Eupteryx melissae) (Hemiptera: Cicadellidae) infestation. Sage leafhopper population on both Turkish and Greek oregano did not significantly vary. The sage leafhopper damage was more severe in the lower part of the canopy than the middle and upper parts. Extensive sage leafhopper feeding dramatically reduced essential oil contents, resulting in 28.8 and 34.8% reductions for Greek and Turkish oregano, respectively. Carvacrol, the major essential oil component of both oregano species, did not remarkably vary between leafhopper infested and non-infested plants. With respect to herbage colour, the brightness, redness and yellowness values were significantly different between infested and non-infested plants. Sage leafhopper damage increased brightness and yellowness but decreased greenness of the oregano herbage. To avoid the feeding damage, it is essential to detect the sage leafhopper problem as early as possible and certain control practices are necessary when the infestation is high.

Chemical Composition and Antioxidant Activities of Leaf and Flower Essential Oils of Origanum onites L. Growing in Mount Ida-Turkey

“…Carvacrol, the most abundant compound of the leaf essential oil, was reported in the essential oils of aerial parts of O. onites from Turkey (18,24,29,39,40) and Greece (22,23,41,42). However, αcubebene and δ-elemene were not reported previously as significant components of O. onites.…”

“…Carvacrol, the most abundant compound of the leaf essential oil, was reported in the essential oils of aerial parts of O. onites from Turkey (18,24,29,39,40)…”

Essential Oils of Oregano: Biological Activity beyond Their Antimicrobial Properties

“…It is also important to mention that the constituents and concentration of the compounds of the EOO usually vary due to a great diversity of factors such as species, pests, soil conditions, harvest season, geographical location, climatic and growth conditions [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. The drying method of the oregano, the extraction technique and the anatomical part of the plant used for extraction also influence the EO yield and composition.…”

Medicinal Uses, Phytochemistry, and Pharmacology of Origanum onites (L.): A Review

“…As a result of phytochemical analyses, the following seven different essential oil chemotypes were identified: carvacrol , thymol , linalool , carvacrol + linalool, carvacrol + 1,8‐cineol + γ ‐terpinene, carvacrol + 1,8‐cineol + linalool, and carvacrol + γ ‐terpinene . Effects of environmental factors, such as insect and/or fungi infections , populational differences , climatic conditions , developmental/ontogenetic stages , diurnal variation , plant type (wild‐cultivated), and isolation technique on the oil composition have also been reported by several researchers.…”

“…This species has widely been used as spicy herb for a long time (thousands of years) due to its aroma and flavor to enhance the taste of foods. In addition to its culinary use, various preparations are used in pharmaceutical and cosmetic industries (for the whole list, please refer to the Table ) .…”