Post-Greenhouse Evaluations of Forced Bulbous Plants 1996 Proposal
POST-GREENMOUSE EVALUATIONS OF FORCED BULBOUS PLANTS
- PHASE II
1. EXECUTIVE SUMMARY
During Phase I of this project, a comprehensive database was established
for 22 species
of flower bulbs forced as potted plants. This information has been
released to the industry in
various publications (see Literature cited) and many lectures given
by the project leaders. In
addition, it will be summarized in the fifth edition of the Holland
Bulb Forcer’s Guide to be
released in Spring 1996.
In Phase II of the project, two areas will be investigated. The first
is related to the post-
Greenhouse longevity of potted Asiatic and Oriental hybrid lilies.
Previous studies have (Phase
I of this program) shown that some lily cultivars have little or no
post-greenhouse life after cold
storage, while others are satisfactory for two to three weeks. Factors
to be studied are: (1)
genetic variation amongst cultivars, (2) the influence of various greenhouse
factors. e.g..
nutrition, and (3) post-storage handling systems. The second area to
be investigated will be the
post-greenhouse requirements and performance of: (1) Ornithogalum dubium,
a potential new
potted plant; and (2) new clones of Paper-white Narcissus that have
been developed by the
Volcani Centre, Bet Dagan, Israel.
All plants in these studies will be forced at N. C. State University
and then transported
to the University of Florida for subsequent evaluations under controlled
interior conditions.
These studies will provide the floral industry with information to
properly market
flowering potted lilies. The result will be that consumers will have
a greater satisfaction with
these floral products and return sales will be enhanced. The studies
on O. dubium and the new
clones of Paperwhite Marcissus are needed to ensure that when new plant
products or cultivars
are released that they will perform satisfactorily not only under greenhouse
conditions but also
under consumer conditions.
INTRODUCTION AND LITERATURE REVIEW
Studies conducted (Nell et al.. 1991; Nell et al., 1992a, 1992b; Nell
et al., 1993: Nell
et al., 1994) on the post-greenhouse requirements of flowering bulbs
as potted plants have
demonstrated that the “Consumer Phase” of forcing is hig y dependent
on the species and
cultivar used. For example, Anemone blanda plants were forced at N.
C. State University.
When they were removed from the areenhouse, they appeared to be excellent
quality potted
plants. However, after being sleeved, packed, and transported by a
commercial flower carrier.
they had no useful potted life for the consumer. Thus, it is essential
that before “New” or
“Improved” potted plants are introduced, they are evaluated under simulated
home conditions
to determine their usefulness. We have conducted limited greenhouse
forcing trials on O.
dubium. This species needs to be evaluated prior to releasing
a forcing program for it.
In addition, our trials (Nell et al., 1993) showed that ‘Galil’ and
‘Ziva’, the two most
widely forced Paperwhite Narcissus (De HerEogh. 1996), has a potted
life of 22 and 26 days,
respectively. The plant breeders at the Volcani Center in Bet Daga,
Israel are increasing four
new clones for potential release. We will evaluate their post-greenhouse
longevity to be certain
that their consumer performance is at lease equal to, and preferably
greater, than the currently
forced cultivars.
The 1994 USDA Floriculture Crops Surnmary indicates that the forcing
of Asiatic and
Oriental hybrid lilies as potted plants is increasing. A total
of 1,541,000 and 1,742,000 were
forced in 1993 and 1994, respectively. In Phase I of this program,
Asiatic and Oriental hybrid
lilies were evaluated.
In the initial experiments (Nell et al., 1995), simulated shipping and
post-greenhouse
conditions were evaluated. Potted Asiatic Hybrid lilies ‘Aristocrat’,
‘Horizon’ and ‘Polka’ were
boxed when the first flower was fully colored but not open. They were
maintained in darkness
(simulated shipping), at 2, 7 or 13 C for 3, 6 or 9 days and then placed
at 21 +/- 2 C at an
irradiance of 14 umol*m-2*s-1 for postproduction evaluation. Maximum
plant longevity of 16 days
was achieved at all temperatures when plants were stored for only 3
days. At 7C, they could
be stored for up to 6 days and for up to 9 days when maintained at
2C. Plant longevity was
reduced by 5 days when transported for 9 days at 13C. Due to the larger
number of floral buds
that fully opened, ‘Aristocrat’ was superior in postproduction performance
when compared to
‘Horizon’ and ‘Polka’. Simulated transport greater than 3) days decreased
flower opening on
‘Horizon’ and ‘Polka’.
In the second experiment, ‘Aristocrat’ and the Oriental hybrid ‘Star
Gazer’ were
evaluated at postproduction temperatures of 18, 21 or 24 C at irradiance
levels of 7 or 14 umol
m-2*s-1 after being commercial transported at 5 +/- 2 C for 4 days.
Most floral buds of ‘Aristocrat’
opened under all postproduction conditions. ‘Star Gazer’ had reduced
flower opening due to
either floral bud abscission or abnormal bud development, which increased
as the postproduction
temperature increased. Maximum flower longevity, total plant longevity
and quality was
achieved with a postproduction temperature of 18C. Postproduction irradiance
had no effects
on the parameters evaluated.
In the 1994-95 trials, the effects of 0, 3, 6 and 9 days of 2C storage
of marketable plants were evaluated.
It was found that ‘Buff Pixie’ could not be cold-stored, while ‘Sun
Ray’ and ‘Miss Burma’ could be stored
for up to 6 days. Thus, with these genetic variations, it is obvious
that expanded studies are needed to provide
a scientific base for not only the forcing of Asiatic and Oriental
Hybrid lilies as potted flowering plants but also
their ability to be stored and shipped.
3. OBJECTIVES AND ANTICIPATED BENEFITS
The overall objective and anticipated benefits to the floricultural industry
is to provide
a scientific database on the post-greenhouse performance of
forced flower bulbs. Therefore, theconsumer, who is the most important person in the marketing chain,
will be satisfied with theproducts purchased. The specific objectives for Phase II of this project
are:
(1) To determine the post-greenhouse performance and
requirements for O. dubium.
(2) To determine the post-greenhouse performance of four
new clones of Paperwhite
Narcissus.
(3) To expand the database on the forcing and post-greenhouse
requirements for
Asiatic and Oriental hybrid lilies as potted plants. We will evaluate cultivars,
greenhouse cultural factors, and post-greenhouse storage conditions.
4. MATERIALS AND METHODS
A. O. dubium. Plants will be forced using
guidelines being developed at N. C. State
University. We will conduct trials on O. dubium in 1996 and 1997. The key
steps are
as follows:
1. 5/6 up cm, in circumference, Israeli-grown bulbs
will be used.
2. Bulbs will be stored at 77F (25 C) until four
weeks before planting, then placed
at 63 F (17 C).
3. The first planting will be on October 15th,
then 4 week intervals will be used.
4. A sandy, very well drained, pH 6 to 7, sterilized
planting medium will be used.
5. Plants will be forced in a medium light intensity
(5.000 ft.c.) greenhouse and at
72/65 F (22/18 C) Day/Night temperatures.
6. Plants will not be fertilized until they begin
to flower and then, very lightly.
7. When 2 to 3 florets are fully colored, they
will be removed from the Greenhouse
benches, packed and shipped to the University of Florida. Plants will be
placed
into interior rooms providing temperatures of 65 (18C), 70 (20C)
and 75 F (23
C) and light levels of 50 and 100 ft-c. 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. Data to be recorded will include:
(1) Height at arrival
(2) Date of final flower opening
(3)) Total number of lowers opening
(4) Total plant longevity
(5) Overall plant quality
B. Paperwhite Narcissus. Clones 9, 10, 11
and 12 will be forced according to guidelines
published in the Holland Bulb Forcer’s Guide (De Hertogh, 1996). These
clones were
found to have commercial potential based on initial trials with 12 clones.
Eight clones
were discarded due to production or forcing problems. When they reach the
“Bud” state
of flower development, they will be packed and shipped to the University
of Florida.
They will be placed at 100 ft.c. and 65 F (18C). Data to be recorded will
include:
Height at arrival
First Stem - first stem to flower
First open flower
Height at flower opening
Longevity of first open flower
Height at death of first flower
Last Stem - final stem to flower
First open flower
Height at flower opening
Longevity of first flower
Height at death of first flower
Total plant longevity
Total plant quality
C. Asiatic and Oriental hybrid lilies. In
1996 and 1997, twenty four of the most readily
available cultivars will be forced according to guidelines published in
the Holland Bulb
Forcer’s Guide. Groups will be planted on separate planting dates so that
one group can
be packed and stored at 2 C for 6 days, while a second group will not be
stored prior to
shipping to the University of Florida. They will subsequently be placed
at 100 ft.c. and
65 F (18C) to determine their post-greenhouse characteristics. Data to
be recorded
include:
Date of first flower opening
Diameter of first open flower
Longevity of first open flower
Date of last flower opening
Diameter of last open flower
Longevity of last open flower
Number of floral buds
Number of floral buds that flowered
Number of date of bud drop
Total plant longevity
Total leaf number and % of leaves browning
Total plant quality
After the genetic characteristics of the cultivars have been established,
subsequent studies
(1997-99) will be conducted on selected cultivars to determine the
effects of nutrition on their
longevity. In addition, post-storage handling
procedures such as lukewarm water and
intermediate temperature acclimation will be conducted on selected
cultivars.
5. LITERATURE CITED
De Hertogh, A. 1996. 5th Edition, Holland Bulb Forcer’s Guide. International
Flower-Bulb
Centre, Hillegom, The Netherlands.
Nell, T.A., J.E. Barrett and A.A. De Hertogh.
1992a. 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. The
Netherlands. 8 pp.
Nell, T.A., J.E. Barrett and A.A. De Hertogh. 1992b. Post-Greenhouse
Longevity of Rooting
Room Bulbs as Flowering Potted Plants. Acta Hort. 325: 175-184.
Nell, T.A., J.E. Barrett and A.A. De Hertogh. 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,
The Netherlands.
Nell, T.A., J. Barrett and A.A. De Hertogh. 1994. Increasing the Longevity
and Quality of
Flowering Potted Bulb Plants. Ohio Florists’ Assoc. Bull. 782: 3-4.
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.
Nell, T.A., R.T. Leonard, A.A. De Hertogh and J.E. Barrett. 1995. Asiatic
and Oriental
Hybrid Lilies as Flowering Potted Plants Influenced by Transport and
Postharvest
Conditions. Hort Science 30(7): 1433-1435.
United States Department of Agriculture. 1995. Floriculture Crops 1994
Summary. National
Agricultural Statistics Service. Agricultural Statistics Board. Washington,
D.C.
6. ANNUAL BUDGET
A. N. C. State University
Labor and supplies for forcing the bulbs, packing and storing
plants (Bulbs ($6,500) will be provided by AGREXCO of Israel and
United Bulb Co.)
$ 7,500.00
B. University of Florida:
Labor and supplies for the collection of data for the
postproduction evaluations (Table 1) once plants are received from
N.C. State University
$18,000.00
TOTAL REQUEST
$25,500.00
7. LEADERS QUALIFICATIONS
August A. (Gus) De Hertogh is a Professor of Horticultural Science
at N.C. State
University. He has developed the procedures used by bulb
forcers throughout North America.
His expertise is recognized world-wide.
Drs. Terril A. Nell and James E. Barrett are Professors of Environmental
Horticulture
at the University of Florida. Dr. Terril A. Nell has established the
flowering potted plant post-
production program at the University of Florida, and Dr. James E. Barrett
is highly recognized
for his knowledge of floriculture growth and development. The post-greenhouse
evaluation
facilities at the University of Florida are the most up to date post-greenhouse
facilities in North
America.
