Pitaya is one of the most preferred and produced tropical fruit species recently introduced to the Mediterrranean region in Turkey. Due to its nutritional fruits with high economic value, the popularity of pitaya increases steadily in Turkey as an alternative crop. No detailed nutritional analysis has been undertaken in Turkey so far on fruits of the pitaya species. In this study, we determined and compared some nutritional parameters in fruit flesh of two pitaya (dragon fruit) species (Hylocereus polyrhizus: Siyam and Hylocereus undatus: Vietnam Jaina) grown in the Adana province located in the eastern Mediterranean region in Turkey. The individual sugars, antioxidant activity, total phenolic content, phenolic compounds and volatiles were determined for the first time in Turkey on two pitaya species. The results showed that total phenol content and antioxidant capacity are notably higher in red-fleshed fruits than white-fleshed ones and the predominant phenolic compound in fruits of both species was quercetin. The total sugar content and most of the phenolic compounds in fruits of two pitaya species were similar. A total of 51 volatile compounds were detected by using two Solid Phase Micro Extraction (SPME) fibers, coupled with Gas Chromatography Mass Spectrometry (GC-MS) techniques, and more volatile compounds were presented in the white-fleshed species. Total phenolic content (TPC) of the red-fleshed and white-fleshed pitaya species were 16.66 and 17.11 mg GAE/100 g FW (fresh weight). This study provides a first look at the biochemical comparison of red-fleshed and white-fleshed pitaya species introduced and cultivated in Turkey. The results also showed, for the first time, the biochemical content and the potential health benefit of Hylocereus grown in different agroecological conditions, providing important information for pitaya researchers and application perspective.

The main aim of this study was to investigate metabolic responses of fruits, leaves, and shoots of pistachio trees (Pistacia vera L. cv. Kirmizi) during their development. Electron paramagnetic resonance spectroscopy revealed significant increase in generation of semiquinone radicals in fruits and leaves of pistachio, while the flower cluster thinning application was conducted in relation to the control; especially at the second term of the plant material collection. Moreover, flower abscission caused an increase in the level of phytohormones such as indole-3-acetic acid and abscisic acid in fruits at the first term of fruits sampling. In turn, high-performance liquid chromatography analysis revealed differences both in the profile as well as the contents of soluble sugars detected in pistachio organs. The highest total sugar content was found in fruits of pistachio where the flower cluster thinning application was made early. Total sugar levels were higher also in leaves and shoots of the above-mentioned pistachio plants in relation to the control until the third sampling time. The importance of high levels of fructose in the fruits following the flower abscission was observed. Additionally, analyses of mineral elements in organs showed that copper and phosphorus contents in fruits were higher after the flower abscission in relation to the control. To conclude, our findings signal on contribution of semiquinone radicals, paramagnetic manganese ions, phytohormones, nutrients, and sugars in pistachio organs development on the background of the flower cluster thinning which was applied before fructification.

Dormancy breakers are widely employed in regions with an insufficient chill accumulation to enhance floral bud break in sweet cherry production. Dormex (HC) has not been authorized in Europe and many other countries due to its detrimental effects on human health (carcinogenic) and the environment. This situation has increased the demand for alternative chemicals to HC. The current study was conducted in an orchard of 5-year-old ‘Royal Tioga^®’ sweet cherry trees (Prunus avium L.) grafted on MaxMa 14 rootstocks in the Karayusuflu Village (at an altitude of 50 m), Adana, a Mediterranean city in Türkiye. Levante (LV) and HC were applied approximately 30 days before the anticipated dormancy break of the buds. Chill accumulation was quantified monthly during the 2023–2024 winter season using the chilling hours below 7.2 °C (467 h) and chill units (280 CUs). This study evaluated the effects of dormancy breakers on hormonal changes in floral buds, focusing specifically on gibberellic acid (GA₃) and abscisic acid (ABA). Also, their impact on fruit set and quality parameters was assessed. The findings revealed that the LV and HC applications reduced the ABA content in flower buds during the dormancy period compared to the control. LV significantly improved bud break rates (56.8%) and fruit set (85.2%) while positively influencing the fruit quality parameters and yield. No significant differences between the LV and HC treatments were observed regarding average fruit weight (8.8–8.4 g) and yield values (3.7–3.5 kg tree⁻¹). These results suggest LV as an alternative to HC for early-season cherry production in warm climates.