Effect of day length, growth regulators and fertilization on the height, plant diameter, number of buds and inflorescences was monitored in the species Aster novi-belgii L. ´Mary Ballard´ throughout three growing seasons in order to explore the possibility of its late-summer growing as a flowering pot plant. The total number of buds and inflorescences was by 20% larger under natural day length compared to plants grown under the shortened photoperiod. Bud opening dynamics was more intensive under the natural day length conditions.
Comparison of the average number of open inflorescences per plant between plants grown under different photoperiod conditions revealed a significantly larger number of open inflorescences in plants grown under the short day conditions. Foliar application of daminozide was shown to be efficient in inhibiting the growth of asters up to 10%. Plant diameter was not much changed under the influence of daminozide, with the exception of second trial year, when it was reduced up to 25%. Daminozide application resulted in an increased number of buds in all trial variants. In all three years, significantly more flowers were determined in fertilized plants compared with non-fertilized, with the exception of plants grown under natural day length in first year of experiment.

daminozide; fertilization; photoperiod; Aster novi-belgii; Michaelmas Daisy

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia