Effects of different sowing dates on flowering phenology of phacelia (phacelia tanacetifolia bentham)

Abstract

This study was conducted in order to determine the flowering phenology on different sowing dates in a mild climate. The experiment was conducted in the autumn and spring vegetation periods of 2013 and 2014 in a randomized block experimental design with three replications. Flowering started on 08.04.2013/02.04.2014 and ended on 22.05.2013/ 26.05.2014 in the autumn sowing period. In the spring sowing period, the first flowering dates were 08.05.2013/18.05.2014, and it lasted until 31.07.2013 /25.07.2014. According to the two years results, it was determined that the average flowering period was 41.9 days. Throughout the five weeks observation period, the peak flower density and bee density per square meter were observed in the third week, respectively, with 943.4 pcs/m2 and 72.06 pcs/m2. Reports of investigated traits, which obtained a value decrease with retarded sowing dates, stated that the flowering period was prolonged when phacelia should be sown in certain intervals between September November and between the beginning of March and beginning of April for beekeeping, which is intensive in this region. It was concluded that phacelia may provide significant contributions on needs of nectar and pollen in the dearth period when the flowering period lasted.