Published in Scientific Papers. Series D. Animal Science, Vol. LX
Written by Valentina CEBOTARI, Ion BUZU, Olesea GLIGA, Olga POSTOLACHI, Nicolae GRANCIUC
The purpose of the research was to estimate the efficiency of pollination by bees of some parental sunflower varieties, depending on the distance between the selected sectors with inflorescences and hives with bees, placed for pollination, was carried out. The experiments were performed on a field of sunflowers, with an area of 36 ha, where maternal variety "Express" and paternal variety "NS-X 6006" (both from Republic of Serbia), destined for crossing to obtain hybrid seeds, were sown alternatively. Around chain have been located 144 bee families, so that there were 4 families per ha. For verifying the self-pollination capacity of sunflower, 4 experimental sectors were selected, at different distances from the beehives - 10, 100, 300 and 500 m. As a control 8 inflorescences were selected in each sector, which before flowering, were covered with gauze. In the phase of full ripening of seeds, from each experimental sector the seeds were collected manually - 8 control-inflorescences and 9 experimental inflorescences (naturally pollinated). For each inflorescence in part were examined: the total number of seeds, number of fertile and sterile seeds, total weight of seeds, weight of fertile and sterile seed (weighed on electronic scales accurate to 0.1 g) and degree of seed's fertility. A result of researches was found that sunflower crops of varieties "Express" and "NS-X 6006" researched by us, are typically entomophilous, because in our experience, self-pollination (isolated) did not occur. The degree of seed's fertility of pollinated by bees inflorescences, varied depending on the distance between experimental inflorescences to the beehives, from 85.7% to 90.3%. The average total mass of the seeds from free pollinated inflorescence was higher compared to that of the self-pollinated inflorescences with 36.6 to 54.0 g or 260-740% (td = 7.5 to 16.3; P < 0.001), hence, pollinating by bees of parental varieties of sunflower "Express" and "NS-X 6006" is quite effective and increases the harvest of seeds from 3.6 to 8.4 times.
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