Honeybees attractant in hybrid colored sunflower seed production crop

Abstract

Africanized honeybee (Apis mellifera), in sunflower (Helianthus annuus) seed production crop, show male-fertile head preference, which decreases seed production. This research work aimed the honeybee visitation increase in male-sterile sunflower heads, with 0.0%, 2.5%, 5.0% and 7.5% (w/v) sucrose solution, applied at sunflower heads in completely randomized design, on 1 ha seed crop production of colored ornamental sunflower strain, in Londrina County, Paraná State, Brazil. It was utilized 15 head for each treatment, on 3 rows internal to the crop. Two hours after the application, the number of honeybees was recorded walking through the rows and observing the number of bees on the marked flowers. The greatest visitation average was in 7.5% sugar dilution (x=0.43±0.11), which was not different from 5.0% (x=0.42±0.08; p>0.05) but significantly different from control heads (x=0.12±0.04; p<0.05) and 2.5% sugar solution (x=0.27±0.06; p>0.05). The number of africanized honeybees showed a 2nd order polynomial response to the tested sugar solution ( = 0,11 +8,40x -53,33x2; R2=0,9865). Sucrose 5.0% solution was capable to increase in four times the bee visitation, opening perspectives to new studies aiming adequate sunflower pollination with Africanized honeybees.