Effects of phenolic-standardized Crataegus orientalis flower extract on honey bee colony development and seasonal honey yield; [Efectos del extracto floral de Crataegus orientalis estandarizado en compuestos fenólicos sobre el desarrollo de colonias de abejas melíferas y el rendimiento estacional de miel]

Aim of study: The aim of this study was to evaluate the effects of a phenolic-standardized flower extract from Crataegus orientalis Pall. on honey bee colony development and end-of-season honey yield under field conditions, and to assess its lasting colony-level effects. Area of study: The study was conducted during the 2025 beekeeping season at the apiary of Bayburt University Beekeeping Application and Research Center, located in northeastern Türkiye. Material and methods: Twenty-four initially balanced honey bee (Apis mellifera L.) colonies were randomly assigned to four groups (n = 6): a control group receiving 1:1 sucrose:water syrup and three treatment groups receiving 50, 100, or 200 mg GAE L⁻¹ of phenolic-standardized Crataegus orientalis flower extract. Colonies were fed daily for 21 days in early spring and monitored at seven time points (T0–T6) from mid-May to late August. Colony development was assessed using brood area (cm²) and number of frames with bees, while hive-front dead bees were recorded as a safety indicator. Net honey yield was determined at the end of the season. Main results: Daily syrup consumption did not differ among groups (P > 0.05), whereas daily phenolic intake increased in a dose-dependent manner (P < 0.05). Brood area increased significantly with dose and was generally higher in the high-dose group than in the control group throughout the season (P < 0.001). No significant differences were observed among groups for seasonal averages of frames with bees or mortality index; however, a significant treatment × time interaction was detected for frames with bees. Net honey yield was significantly higher in the high-dose group compared to the control group (P < 0.01). Research highlights: Short-term early spring supplementation with phenolic-standardized Crataegus orientalis flower extract supported brood development without increasing adult bee mortality. This early developmental advantage resulted in a measurable improvement in end-of-season honey yield under field conditions.