Post-Greenhouse Evaluations of Forced Bulbous Plants Progress Report — June 1997
Date 5/2/97
Title of Project Post-Greenhouse Evaluations of Forced Bulbous
Plants - Phase II
Institution where work is being conducted N. C. State University and
University of Florida
Amount of Endowment Grant $12,000
Covering Period 7/1/96 to 6/30/97
Anticipated Date of Project Completion/Final Report 6/98
Individual(s) Conducting Project:
(List Project Leader First)
Dr. Terril Nell- Title Professor
Telephone Number (904) 392-1829
Dr. James Barrett -Title Professor
Dr. A.A. DeHertogh -Title Professor
- I.General AspectsThis is a cooperative project between North Carolina State University
(NCSU) and the University of Florida (UFL). All aspects of the programming
and greenhouse phases of forcing are performed at NCSU. Subsequently, the
post-greenhouse evaluations for the marketing and consumer phases are performed
at UFL. Thus, two Progress Reports are submitted. In this Part, I shall
report primarily on the initial phases of the forcing process.
- II. Asiatic and Oriental Hybrid Lilies as Flowering Potted Plants
- 1. Industry Needs and Project ObjectivesIn North America, the forcing of Asiatic and Oriental Hybrid lilies
as flowering potted plants has been slowly increasing over the past few
years. There is a need, however, to identify specific forcing procedures
and cultivars that will provide consumers with high performance plants.
The objectives of our trials is to evaluate all basic greenhouse procedures,
post-greenhouse storage capabilities, and cultivar performance of this
large group of plants.
2. Cold Storage Trials
- a. ‘Buff Pixie’, ‘Sun Ray’, ‘Miss Birma’, and ‘Star Gazer’ wereforced to the market stage of floral development and subsequently stored
at 2 C (35 F) for 0, 3, 6, or 9 days. Subsequently, they were sleeved,
boxed, and transported to UFL. This was the third and last year of this
trial. Results of years one and two indicate that the bulb production year
significantly affects the post-greenhouse performance of these cultivars.
We are attempting to confirm this response in 1996/97. It was also found
that ‘Sun Ray’ is very tolerant to 2 C (35 F) cold storage. It was followed
by ‘Miss Birma’ and ‘Buff Pixie’. ‘Star Gazer’ did not store well.
b. Future Trials and Anticipated Benefits to the Industry
The 1996/97 season will conclude this series of trials. The results
will be summarized and an article written for industry use.
- 3. Trials on Forcing Procedures and Cultivar Evaluations
- a. Twenty-five cultivars and six genetic selections have beenevaluated in 1995/96 and 1996/97. Two cultivars and three selections were
found to be unacceptable either due to excessive ‘Leaf Tip Scorch’, a low
number of flowers produced, and/or susceptibility to flower abortion. It
appears that only Ca (NO3)2 and KNO3 should be used for fertilization of
‘Star Gazer’ since 14-14-14 Osmocote, either alone or in combination, promoted
leaf chlorosis. Also, it appears the BanrotTM fungicidal dip and drenches
will reduce foliar chlorosis of Oriental lilies. Of the 25 cultivars evaluated,
the post-greenhouse performance of nine cultivars was found to be satisfactory.
The primary disorder of cultivars that were unacceptable was “Leaf Yellowing”.
b. Future Trials and Anticipated Benefits to the Industry
These trials will be continued. Plant breeders and forcers will be
informed of those cultivars and selections that will provide consumers
with maximum satisfaction.
- III. Paperwhite Narcissus as Flowering Potted Plants
- 1. Industry Needs and Project ObjectivesAll “Paperwhites” forced in North America are produced in Israel. Currently,
two cultivars represent almost 100% of the production. ‘Ziva’ is a tall
cultivar and always requires post-greenhouse staking, while ‘Galil’ is
degenerating as a commercial cultivar.
2. Trials in Progress
Trials were carried out to evaluate four new “Paperwhite” cultivars
and the use of ethephon sprays to eliminate the staking of ‘Ziva’. Preliminary
results indicate that ‘Ariel’ is a superior cultivar. It can be forced
early, does not require staking, and does not develop “Leaf Tip Yellowing”.
In addition, it appears that ethephon can be used to control “Stem Topple”
of ‘Ziva.’
3. Future Trials and Anticipated Benefits to the Industry
These trials will be repeated to confirm the preliminary results. In
the meantime, efforts are being made to have ‘Ariel’ increased for future
commercial release. This cultivar should increase consumer satisfaction
of “Paperwhites.”
- IV. Ornithogalum dubium as a Flowering Potted Plant
- I . Industry Needs and Project ObjectivesThe floriculture industry has indicated a need for new flowering potted
plants. 0. dubium is a species which has demonstrated considerable promise.
Our goal is to develop a complete forcing program which will include post-greenhouse
performance for the consumer.
2. Summary of Trials in Progress
The cultural requirements (temperature, planting medium, light, etc.)
are being developed simultaneously with the post-greenhouse trials. Plants
are forced until they develop three fully colored (or open) florets. They
are subsequently sleeved and shipped. The initial trial in 1995/96 indicated
that plants are satisfactory for a minimum of four weeks. Trials are in
progress in 1996/97 to confirm this response.
3. Future Plans and Anticipated Benefit to the Industry
If high quality potted plants can be forced, 0. dubium will be an excellent
species for either 4 inch diameter pots containing one bulb or 7 to 8 inch
diameter pots containing five, seven, or nine bulbs. Since the initial
flowering of the plants is not uniform, studies will be conducted on storage
requirements of the marketable plants prior to shipping. In addition, since
the primary flower color of the species is orange, new lines with other
flower colors will be evaluated.
