Standardization of managed honey bee (Apis mellifera) hives for pollination of Sunflower (Helianthus annuus) crop

To determine the effect of honey bee (Apis mellifera L.) pollination on sunflower yield using the most appropriate number of beehives per unit area of crops is very important. By comparing the number of hives and yield components, we can satisfy optimal pollination needs and improve economic yields. For this purpose, a series of experiments were conducted at thatha Khalil farmer field Taxila Rawalpindi, under the supervision of Beekeeping and Hill Fruit Pests Research, Station Rawalpindi, Pakistan, with four treatments for comparison: 1 hive acre−1, 2 hives acre−1, 3 hives acre−1, and 0 hives acre−1 as a control. The hives were kept inside the experimental area and pollination density, pollinator’s diversity, agronomic yield, and economic yield were determined. Two acres of sunflower field were sown and four bee colonies were introduced at 5% to 10% flowering. The maximum visitation frequency of A. mellifera was recorded at the weekly interval from 24 to 09-2019 to 24–10-2019, according to which maximum visitation was observed (44.8, 38.4, and 16.5 plant−1 5 min−1) at 10:00, 12:00, and 14:00 hrs, respectively. Data regarding foraging pollinators revealed that A. mellifera was the most dominant pollinator of the sunflower crop with the highest abundance 17.11% followed by A. cerana (3.46%) and the population of A. dorsata was minimum (2.12%). Furthermore, agronomic parameters (number of seeds plant−1, 100 seed weight (g), and economic yield were significantly higher in those fields which were pollinated by more beehives in comparison to fewer beehives.