Post-Greenhouse Evaluations of Forced Bulbous Plants 1994 Proposal
Proposal objective - The basic objective of these post-greenhouse
experiments is to establish a comprehensive data base to determine the
effective home-life of selected non-rooting room forced bulbous and tuberous
flowering potted plants. Similar work has been completed and published
in trade magazines on rooting room bulbs as part of this project. Amaryllis,
Astilbe, Caladium, Dahlia, Freesia, Leucojum, Asiatic Lily, Oriental Lily,
Paperwhite Narcissus, Scilia and Zantedeschia will be forced to the optimal
marketing stage at N.C. State University, transported to the University
of Florida and subsequently evaluated under controlled interior conditions.
Longevity of all flowering potted bulbs, except Amaryllis and Lily, will
be determined at interior temperatures of 65, 70 and 75′F and 50 and 100
ft-c. of light, based on specific quantitative criteria, such as bud drop,
flower longevity, stem elongation etc. Amaryllis will be treated with Ethephon
prior to marketing stage to determine if stem elongation can be minimized
without a loss in interior longevity. Asiatic and Oriental lily will be
treated with STS to determine effectiveness in preventing bud drop.
Benefits to the industry - This information is needed to provide
the floral industry with data to encourage proper marketing and consumer
utilization of these flowering potted plants. The end result will be that
the consumer will enjoy a greater satisfaction with these floral products
and return sales will be enhanced. Results of our previous studies on rooting
room bulbs will be presented in a technical bulletin and trade journal
article during the coming year to provide the industry with ready access
to this information.
INTRODUCTION AND LITERATURE REVIEW
The United States floral industry has been forcing spring flowering
bulbs and non-rooting room bulbs as either cut flowers or potted plants
for a number of years. DeHertogh has developed many of the requirements
for successful cooling and forcing of spring flowering bulbs. Postharvest
studies have been conducted to extend cut floral life with floral preservatives
(Staby and Naegele, 1984) or to develop the optimal storage conditions
for cut bulb flowers (Hopper and Carlson, .1985), while this project investigates
potted flowering bulbous plant longevity. Vase-life studies have also been
conducted on tuberous plants (De Hertogh, 1989). To the best of our knowledge,
there have been no studies reported on the home-life of bulbs forced as
potted plants prior to the commencement of this research in 1988.
In our 1988-93 trials, we found significant effects of interior temperature
on the interior performance and longevity of a number of rooting room and
non-rooting room bulbs (Nell et al., 1991, 1992, 1993). Interior light
level did not have a major influence on longevity but some effects on plant
quality were observed. The research proposed for 1993-94 will expand the
results obtained over the past four years by evaluating additional species.
Also, a number of handling/longevity problems observed in previous experiments
will be addressed.
MATERIAL AND METHODS
A series of experiments will be conducted to identify the effects of
interior light, temperature and transit conditions on forced flowering
potted bulbous and tuberous plants. All experiments will be repeated (shipped)
at 3 different times (Table 1).
A. Interior Light Level and Temperature
Plants will be forced in Raleigh and shipped to Gainesville
at time of marketability. Bulbs will be placed into interior rooms providing
temperatures of 65, 70 and 75′F and light levels of 50 and 100 ft-c. In
other words, there will be a total of 6 treatments for each bulb species.
Light will be provided 12 hours daily from cool white fluorescent bulbs.
Temperature and humidity (50- 55%) will be constant during the day/night
period. Our efforts in 1993 - 1994 will concentrate on longevity of non-rooting
room bulbs (Table 2). Also, this table provides information on the bulb
species completed in 1988 - 1993 relative to those being evaluated in the
coming year. In each case, we feel that at least two years of evaluations
are required for accurate development of the effects of temperature and
light level on longevity. Data to be taken includes dates of opening and
death for first and last open flowers; flower diameters, colorometric analysis
of flower color, initial and final plant height and number of open flowers.
Clearly, data will vary with plant species as outlined in Table 3. All
data will be subjected to analysis of variance and regression analysis
in order to establish differences between temperature and light levels.
B. Effect of Ethephon on Postproduction Performance of Potted Amaryllis
Amaryllis interior longevity has been excellent in our trials.
However, two postproduction problems have been observed - poor root development
during production has reduced interior longevity and excessive stem elongation
indoors has resulted in plants and pots falling over after 5 - 7 days indoors.
The root development problem was solved by changing the growing medium.
We evaluated the use of Ethephon to minimize shoot elongation. Preliminary
results suggested that height could be reduced but longevity was shortened
significantly in treated plants. These results must be confirmed in the
coming year to prevent problems for the floriculture industry.
In this study, we will evaluate the use of Ethephon (this material reduces
stem topple in hyacinths) during production as a means of improving the
postproduction performance of potted Amaryllis. Two Amaryllis varieties
will be treated with Ethephon at 2 concentrations when the shoots are either
15 or 25 cm tall. Data will includes total plant/flower longevity, number
of buds, and parameters to assess plant quality.
C. Effect of STS on Asiatic Lily and Oriental Lily Bud Drop
Budded Lilies will be treated with STS, then moved to interior
rooms at 50 ft-c and 70′ F. Bud drop and longevity will be compared in
STS treated and non-treated plants.
LITERATURE CITED
1. De Hertogh, A.A. 1989. 4th Edition, Holland Bulb Forcer’s Guide.
International Flower-Bulb Centre, Hillegom, The Netherlands.
2. Hopper, D. and W. H. Carlson. 1985. The What, When and How of Flower
Storage. Mich. Florist, Feb. pp 16-17.
3. Nell, T. A., J. E. Barrett and A. A. DeHertogh. 1993 Post-Greenhouse
(Consumer) Requirements for Non-Rooting Room Bulbs Forced as a Potted Plant.
Holland Flower Bulb Technical Service Bulletin No. 38. Netherlands Flower-Bulb
Institute. Hillegom, Holland.
4. Nell, T. A., J. E. Barrett and A. A. DeHertogh. 1992. Post-Greenhouse
(Consumer) Requirements for Rooting Room Bulbs Forced as Potted Plants.
Holland Flower Bulb Technical Service Bulletin No. 34. Netherlands Flower-Bulb
Institute. Hillegom, Holland.
5. Nell, T. A., A. A. De Hertogh and J. E. Barrett. 1991. Bulbs as
Flowering Potted Plants - Keys to Increased Longevity. Grower Talks 55(7):
57-60.
6. Staby, G. and B. Naegele. 1984. The Effects of STS on Vase-Life
of Flowers. Florist’s Rev. Oct. 25, pp. 17-21.
BUDGET
1993-94 Total requested is $12,000/year.
This funding will cover the following costs:
A. N.C. State Univ. -
Labor and supplies for growing and packing the bulbs with be $3,500.
Bulbs ($6,500) will be provided by the Dutch Bulb Exporters Association
and Bates and Sons Caladiums, Lake Placid, Florida.
B. University of Florida - $8,500.
This funding will provide labor and supplies for the collection of
data for the postproduction evaluations (as shown in Table 1) once plants
are received from North Carolina State University.
LEADERS QUALIFICATIONS
Gus Dehertogh is responsible for development of the procedures
used by bulb forcers throughout North America. His expertise is recognized
world-wide.
Terril A. Nell established the flowering potted plant post-production
program at the University of Florida and Jim Barrett is highly recognized
for his knowledge of floriculture growth and development.
