Received for publication 21 Jan. 1992. Accepted for publication 1 July 1992. The cost of publishing
this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.
for use in floral arrangements. Allowing >5 cm of flower heads to color before harvest will often result in senescing heads at the tip of the spikes and unmarketable products.
The quality and postharvest life of many cut flowers can be improved by supplying flowers with sucrose in the vase solution (Halevy and Mayak, 1979). The effects of sucrose are particularly evident when supplied to flowers that are harvested at bud on the postharvest performance of brodiaea.
The effects of soluble sugars on postharvest performance of cut liatris were studied by Borochov and Keren-Paz (1984). They placed tight-bud stage inflorescences in solutions containing 1% or 5% sucrose for 4 days and then transferred them to solutions without sucrose. Vase life was considered terminated when the upper five flower heads stage (Mayak et al., 1973). Sucrose can be applied as pretreatment (i.e., pulsing) or as a continuous supply in the vase solution. Most
flowers respond favorably to a continuous supply of sucrose in the vase solution, but the effect of pulsing varies considerably, depending on the plant species. Pulsing with high concentrations of sucrose solutions significantly improves the vase life of gladioli [(Gladiolus grandiflora) = (G. ×hortu-1anus Bailey)] (Mayak et al., 1973), whereas the same treatments have no effects wilted. Pulsing stems in sucrose solutions for4 days increased the length of the inflorescence
showing color and the aesthetic value of the inflorescence, The study concluded that pulsing stems in 5% sucrose solution
improves postharvest performance of cut liatris that are harvested at the tight-bud stage. I found no reports in the literature of the effects of a continuous supply of sucrose in the vase solution on the postharvest performance
of cut liatris, nor on how sucrose in vase solutions affects the development and senescence of the flower heads. This study investigated the effects of sucrose in the vase solution on the development and longevity of individual flower heads and its effects on extending the postharvest life of liatris spikes Plant materials. Liatris spicata corms purchased from a commercial supplier were grown in a 17C night temperature greenhouse at the Univ. of Massachusetts. Unless otherwise specified, spikes were harvested when the first head started to show color. They were immediately brought to the laboratory,pruned to 60 cm long, and the basal 10 cm of the leaves was removed. For vase life evaluation, individual spikes were placed in tubes containing »60 ml of vase solution and evaluated in a room at 24C and illuminated
with 10 µmol·m-2·s-1 cool-white fluorescent light for 24 h. The vase life of the individual heads was considered terminated when all florets in the head had senesced. Vase life of the spike was terminated when
one-third of the open flower heads had senesced