(1) Background: Citrus honey constitutes a unique monofloral honey characterized by a distinctive aroma and unique taste. The non-targeted chemical analysis can provide pivotal information on chemical markers that differentiate honey based on its geographical and botanical origin. (2) Methods: Within the PRIMA project “PLANT-B”, a metabolomics workflow was established to unveil potential chemical markers of orange blossom honey produced in case study areas of Egypt, Italy, and Greece. In some of these areas, aromatic medicinal plants were cultivated to enhance biodiversity and attract pollinators. The non-targeted chemical analysis and metabolomics were conducted using ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS). (3) Results: Forty compounds were disclosed as potential chemical markers, enabling the differentiation of the three orange blossom honeys according to geographical origin. Italian honey showed a preponderance of flavonoids, while in Greek honey, terpenoids and iridoids were more abundant than flavonoids, except for hesperidin. In Egyptian honey, suberic acid and a fatty acid ester derivative emerged as chemical markers. New, for honey, furan derivatives were identified using GC-MS in Greek samples. (4) Conclusions: The application of UHPLC-HRMS metabolomics combined with an elaborate melissopalynological analysis managed to unveil several potential markers of Mediterranean citrus honey potentially associated with citrus crop varieties and the local indigenous flora.

This study investigated the effects of harvesting at different plant maturation stages on the fruit and essential oil yield as well as its compositions of anise. It was carried out at El-Baramoon Research Farm, Mansoura Horticulture Research Station, HRI, ARC, Egypt, during the winter seasons of 2013/2014 and 2014/2015. The plants were harvested at eight different fruit development stages and determinations were made of the yields of fruit , germination percentage the thousand fruit weight (seed index), the essential oil percentage and its constituents. The obtained results indicated that high yield and quality of anise fruits were obtained when fruits harvested at stage 4 (the primary umbel was matured completely).The highest essential oil percentage was higher in stage 1 (the primary umbel was at the beginning of waxy stage.). However, this high percentage of essential oil did not produce the maximum oil yield per plant in stage1 was associated with low fruit yield. Essential oil yield per plant with high Trans-Anethole content reached their maximum when fruits harvested at stage 4. Generally, it could be recommended that to obtain the maximum fruit yield and quality as well as high essential oil yield with high Trans-Anethole content, anise fruits should be harvested at stage 4 (The primary umbel was matured completely).

This study was conducted at El-Baramoon Research Farm, Mansoura Horticulture Research Station, HRI, ARC, Egypt during two successive winter seasons of 2013/2014 and 2014/2015. The objective of this study was to determine the effect of harvesting stages on the quality of fennel fruits. The experimental design was a randomized complete block design with four replications. Variations of fruit yield per plant, seed index, germination behavior and essential oil content and composition were studied during different maturation stages. The obtained results indicated that, maximum yield and quality of fennel fruits in terms of fruit yield, thousand fruit weight (seed index) and germination percentage were reached their maximum at stage 4 (the primary umbel was matured completely). Essential oil percentage was higher in the early harvesting stages, while essential oil yield per plant reached its maximum when fruits were harvested at stage 4. The composition of volatile components of the essential oils extracted from fruits at eight stages of maturity was studied by gas chromatography and five main compounds were identified. The first major component was Methyl chavicol ranged from 72.34% to 88.67% and increased gradually with increasing fruit age to reach its maximum at stage8 (the primary umbels were falling). It could be recommended from the previous results the highest fruit yield and quality as well as essential oil yield were obtained in fennel when fruits harvested at stage 4 under the condition of this experiment.

Silicon (Si) and biochar (Bc) are key signaling conditioners that improve plant metabolic processes and promote drought tolerance. However, the specific role of their integrative application under water restrictions on economical plants is not yet well understood. Two field experiments throughout 2018/2019 and 2019/2020 were conducted to examine the physio-biochemical modifications and yield attributes of borage plants mediated by Bc (9.52 tons ha−1) and/or Si (300 mg L−1) under different irrigation regimes (100, 75, and 50% of crop evapotranspiration). Catalase (CAT) and peroxidase (POD) activity; relative water content, water, and osmotic potential; leaf area per plant and yield attributes; and chlorophyll (Chl) content, Chla/chlorophyllidea (Chlida), and Chlb/Chlidb were considerably reduced within the drought condition. On the other hand, oxidative biomarkers, as well as organic and antioxidant solutes, were increased under drought, associated with membrane dysfunction, superoxide dismutase (SOD) activation, and osmotic adjustment (OA) capacity as well as a hyperaccumulation of porphyrin intermediates. Supplementation of Bc and Si lessens the detrimental impacts of drought on several plant metabolic processes associated with increasing leaf area and yield attributes. Their application under normal or drought conditions significantly elicited the accumulation of organic and antioxidant solutes as well as the activation of antioxidant enzymes, followed by lessening the formation of free radical oxygen and mitigating oxidative injuries. Moreover, their application maintained water status and OA capacity. Si and/or Bc treatment reduced protoporphyrin, magnesium-protoporphyrin, and protochlorophyllide while increasing Chla and Chlb assimilation and boosting the ratio of Chla/Chlida and Chlb/Chlidb, resulting in a rise in leaf area per plant and yield components following these modifications. These findings highlight the significance of Si and/or Bc as (a) stress-signaling molecule(s) in regulating defensive systems in drought-affected borage plants by boosting antioxidant aptitude, regulating water status, and accelerating chlorophyll assimilation, thus leading to increasing leaf area and productivity.

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