Evaluation of the apicultural value of sunflower hybrids

Sunflower is one of the most important bee-pasture crops and the leading oil crop plant in Hungary. There are very few studies concerning the nectar production of the plant, most of which consist only of partial data that show the apicultural value of sunflower under intensive cultivation conditions.The nectar production and nectar sugar concentration of six sunflower hybrids, Arena, Alexandra, Cledor, Coriste, Hysun 321 PR and Louidor, were examined in Mezőhegyes (south-east Hungary) from 2002 to 2004. The aim was to determine the nectar production and overall apicultural value of the hybrids. In the experiment the agroecological conditions were also examined and recorded. These agroecological conditions showed a distinctive effect on the consistency of the apicultural values of the hybrids.It can be determined from the results that the nectar production and its sugar content can be modified measurably by external factors. The nectar quantity was measurably increased by abundant precipitation during flowering, while an increase in the nectar sugar content was caused by excessively low air temperature. During these three years the average nectar production of the hybrids was 0.147 mg/floret, with a sugar content of 48.8%. Significant differences were found between the hybrids in nectar production and in the nectar sugar concentration.Averaged over three years Coriste displayed the best apicultural value. Its nectar production was stable and high (0.167 mg/floret). Its high sugar content (49.1%) also proved to be attractive to honey bees (sugar value 0.082). The lowest apicultural value was displayed by the hybrid Alexandra, with a sugar value of 0.059. This suggests that the honey production value of the individual hybrids should be taken into consideration during the selection of bee pastures.