Shoot tip samples of ten plants per treatment were taken
when the second, fourth, sixth, and eighth leaves were fully expanded and were dissected under a binocular microscope
to examine flower bud differentiation and development. Based
on the method of Marc and Palmer (1981) with slight modification,
flower bud development was divided into 9 stages
as shown in Table 1. Twenty plants per treatment were used
to determine time to visible flower bud (VFB) and days to
flower. At flower opening, cut flower quality was evaluated for
10 plants per treatment. Flower opening was defined as when
ray florets had expanded perpendicular to the stem attachment.
Data taken for quality evaluation involved: stem length
from soil surface to calyx attachment; weight of cut flowers
harvested at the stem base; stem diameter at 10 cm below
calyx attachment; the number of true leaves; node number
including cotyledonary one; ray floret number; and capitulum
diameter (the longest distance between the tips of opposite
ray florets). Data were subjected to an analysis of variance
(ANOVA) and means were compared by Scheffe’s multiple-range
test.