Abstract

ABSTRACT Field studies were carried out at New Developmental Farm (NDF), The University of Agriculture-Peshawar, (34.01° N, 71.53° E)Khyber Pakhtunkhwa-Pakistan during spring and fall 2012 and 2013. Objectives of current trial were to assess visitation pattern of Apis mellifera and A. florea and to examine their influence on yield increase as well as on oil contents of sunflower seed. Frequent visitations of A. mellifera observed at 1200 noon, where 29 individuals of bee visitors were found on sunflower blossoms. The next high (25 honeybee/3 m2) visitation rate of bee was recorded at 1400 h. Individuals of A. florea showed two peaks of visitation between 1400 to 1600 h. First peak (15 honeybee/3 m2) was recorded at 1600 h, whereas second peak (12 bees) was recorded at 1400 h. Lowest visitation rate of both species was noticed during evening after 1800 h. High frequency of both speciesfound engaged in foraging during 20th and 25th day after initiation of blooms on sunflower due to more number of pollen and nectar. Minimum number of honeybees was recorded during initial and very last days of flowering due to less number of plants with blooms and less availability of pollens and nectar on flowers. Maximum seed production as well as oil contents was obtained from sunflower plots kept under natural conditions, where bee visitors had access to sunflower blossoms. In contrast, sunflower plots covered with insect-proof bags gave minimum seed production and oil contents, which most probably was because of bee visitors denied to forage on flowers of the crop. Results revealed that sunflower in blooming stage attracted large number of bee visitors particularly Apis mellifera and A. florea. Visitation/foraging of honeybee contributed significantly towards increase in the yield and quality of sunflower seed.