Increasing Flowering Potted Plant Longevity 1994 Proposal
Plants
This project will investigate the practical methods for growers, shippers
and retailers to optimize the longevity of several flowering potted plants.
Interior longevity of hydrangea, elatior begonia, cyclamen, cineraria,
and calceolaria will evaluated when grown with different fertilizer levels,
fertilizer termination and light levels. Also, these plants will be evaluated
after simulated transport for 0, 3, 6 or 9 days at 40 or 60′F or at simulated
retail display conditions of 65, 70 or 75′F at 50 or 100 ft-c. The results
of this project will provide useful information on producing and maintaining
quality of flowering plants to all segments of the industry.
INTRODUCTION AND LITERATURE REVIEW
Quality will characterize business success in the 1990s, according
to numerous consumer and marketing experts. The floriculture industry is
no exception! In today’s market, florists and mass market buyers are demanding
flowering plants that demonstrate increased performance, as well as attractive
physical characteristics. Repeat consumer purchases are discouraged by
flowering plants that fade, wither and die under ordinary interior conditions.
So emphasis in the 1990s will focus on producing plants that are durable,
resilient and long lasting, as well as beautiful. Today, 75 percent of
pot mums are sold through supermarkets, according to a recent study by
Yoder Brothers. Unfortunately, poor handling practices and undesirable
environmental conditions in supermarkets and mass markets contribute to
the rapid decline of floral products (8).
Variation in production practices results in considerable variation
in longevity of flowering potted plants produced by different growers (15).
Modifying production and handling practices can improve flowering plants
for the consumer. Good growers build quality into their plants from the
time they select varieties until they ship plants from the greenhouse to
the retail store. Each decision about variety selection, cultural practices,
production environment storage, transport conditions and retail environment
can have a major impact on plant longevity. Quality is achievable by establishing
the factors and conditions affecting quality and then incorporating these
specific criteria into production protocols. Achieving quality doesn’t
necessarily mean increasing cost.
Growers can virtually assure flowering potted plant longevity by selecting
varieties known to tolerate low interior light conditions as well (5,7).
Interior longevity of chrysanthemums can be increased from 13 to 28 days
while poinsettia leaf drop can be reduced from 90 to 20% by selecting varieties
resilient to interior conditions.
Production practices have long been oriented toward producing plants
sized to respond to designated markets. Product size will continue to be
important. But, growers can modify fertilizer levels, fertilizer duration,
light level, temperature and growing medium to maximize longevity (10).
Our program at the University of Florida has demonstrated benefits of terminating
fertilizer on chrysanthemums and poinsettias during the final two to three
production weeks (5). Stopping fertilizer applications during the final
production stages increased chrysanthemum longevity and reduced incidence
of bract edge burn of Gutbier V-14 Glory poinsettia (6,7). With Easter
lilies, however, preliminary work has indicated that fertilizer termination
isn’t beneficial, so fertilizer applications must be continued until this
crop is marketed to avoid premature leaf yellowing. Azaleas and spring
flowering bulbs do not require fertilization during forcing and longevity
is decreased when fertilizer is used. Success of fertilizer termination
for each grower is determined by fertilizer levels used, growing media
and crop. Growers currently using high fertilizer levels throughout the
entire production period will experience greater benefits than growers
already using optimum fertilizer levels or reducing fertilizer levels at
the end of the crop.
Conditions during shipping and retail can have an equally strong impact
on the quality of the plants for consumers. Improper shipping temperature,
extended shipping duration and presence of ethylene can rapidly diminish
the quality of flowering potted plants (4). Likewise, high levels of ethylene
during display can lead to bud drop, leaf yellowing and drop and numerous
other detrimental effects on flowering plants (1,2,3). Low light during
display can increase bud drop and reduce longevity of some crops (9).
The research results summarized above demonstrate the large amount of
information known about the longevity of poinsettias and chrysanthemums
and the limited amount of information available regarding other flowering
potted plants sold in the United States (9). Relationship of specific cultural
practices to longevity and tolerance to stresses during transport and retail
display conditions is clearly dependent on plant species and variety, Thus,
it is imperative that a comprehensive program be established to methodically
identify the production, transport and retail display conditions necessary
to optimize flowering potted plant longevity.
OBJECTIVES AND ANTICIPATED BENEFITS
1. To identify the effects of fertilizer level, fertilizer termination,
production temperature and light level on the production quality and postproduction
performance of flowering potted plants
2. To determine the effects of low ethylene levels on the interior
performance of flowering potted plants
The results of this project will provide useful information on producing
and maintaining quality of flowering plants to all segments of the industry.
MATERIALS AND METHODS
Studies will be conducted with a number of flowering potted plants
as part of this project. Plants will be grown in fan and pad cooled greenhouses,
or in air conditioned greenhouses at the University of Florida, Gainesville,
using standard commercial production practices for each crop.
A. Evaluation of production, transport and retail handling conditions
on longevity of flowering Potted plants
Elatior begonia, Hydrangea, Cyclamen, Cineraria and Calceolaria will
be grown to flowering then placed into interior rooms for evaluation. A
cooperator at a northern university or a grower may have to be used for
the cool weather crops. Initially, plants will be grown with standard conditions.
Then, plants will be grown with different fertilizer levels, fertilizer
termination and light levels and longevity evaluated at 70 ft-c. and 70′F.
Shipping studies will be conducted using shipping times of 0, 3, 6 or 9
days at temperatures of 40 and 60′F, after which plants will be evaluated
in the interior rooms. Retail conditions will be evaluated at temperatures
of 65, 70 and 75′F and light levels of 50 and 100 ft- c.
B. Evaluation of low (simulated supermarket) ethylene levels on longevity
of flowering potted plants Ethylene is known to damage a number of flowering
potted plants, especially at high levels. These studies will be conducted
to determine the effects of low ethylene levels on flowering plant longevity
as though the plants were on display in a supermarket. Plexiglass or glass
containers with a flow-through air system will be constructed to allow
for plants to be “gassed” with low ethylene levels (50- 200 ppb) for 3
days at 70′F. Then, “gassed” plants will be placed in non-ethylene rooms
for comparison with non-treated plants. Initially, roses will be used for
the evaluations, but we will evaluate other plants once the system is fully
operational.
LITERATURE CITED
1. Agnew, N. H., M. L. Albrecht and R. K. Kimmins. 1985. Reducing corolla
abscission of Streptocarpus X hybrids under simulated shipping conditions
with silver thiosulfate. HortScience 20:118-119.
2. Cameron, Arthur C. and Michael S. Reid. 1983. Use of silver thiosulfate
to prevent flower abscission from potted plants. Scientia Horticulturae.
19: 373-378.
3. Halevy, A. H. and A. M. Kofranek. 1976. The prevention of flower
and leaf abscission in pot roses during simulated transport. J. Amer. Soc.
Hort. Sci. 101:658-660.
4. Nell, T. A. 1990. Commercial transport of flowering potted plants.
Grower Talks 53(9):24-39.
5. Nell, T. A. and J. E. Barrett. 1990. Flowering Potted Plants, Maximizing
Longevity. SAF. October 20-22.
6. Nell, T. A. and J. E. Barrett. 1991. Plan now to eliminate bract
edge burn in your ‘91 poinsettias. GrowerTalks 54:18-19.
7. Nell, T. A.. 1991. How to make long lasting top performers out of
your pot mums. GrowerTalks 54:67-80.
8. Nell, T. A. 1992. America’s supermarket shopping list: fruit, fish
and flowers! GrowerTalks 56(6):59-60, 62, 67.
9. Nell, T. A. 1993. Flowering Potted Plants - Prolonging Shelf Life.
Ball Publishing Co. Batavia
10. Scott, L. F., T. M. Blessington, and J. A. Price. 1984. Influence
of controlled release fertilizers, storage duration and light source on
postharvest quality of poinsettia. HortScience. 19:111-112.
11. Staby, G. L. and A. M. Kofranek. 1979. Production conditions as
they affect harvest and postharvest characteristics of poinsettias. J.
Amer. Soc. Hort. Sci. 104:88-92.
BUDGET
This project will include our work (T. A. Nell and J. E. Barrett),
R. T. Leonard (state supported biological scientist assigned to Terril
Nell), and one Master of Science and one doctoral student.
Supplies, greenhouse and interior space $6000
Labor for assistance in growing plants and taking and analyzing data
9000
Ethylene chambers 3500
TOTAL 18,500
LEADER QUALIFICATIONS
Terril A. Nell established the University of Florida
program on postproduction handling of flowering potted plants.
Jim Barrett is recognized through the U.S. for his knowledge
of flowering plant growth and development.
