Production and Ethylene Strategies to
Increase Longevity of Flowering Potted Plants

Terril A. Nell and Ria Leonard, University of Florida,
Department of Environmental Horticulture, Gainsville, Florida, 32611-0670,
Phone: 352-392-1831 Fax 352-392-3870 E-mail:

We live in a global society. There is no place in the world
that cannot be physically reached within 24 hours, and the internet has made
international communication a snap. Borders exist, but satellites that circle
the globe and cables that snake across ocean floors bounce and ferry signals
that blur the lines of continent, country, and state. In an international
marketplace, where purchasing chocolates from France, pastry from the Mideast,
and seeds from the Southwest is an easy electronic transaction done in the
privacy of your own home, how do growers compete to earn a portion of consumers’
discretionary income? The answer is simple: Deliver quality flowers.

Many of the flowering potted plants sold in the U.S. today
are marketed through supermarkets and "Big Box" stores where poor
handling is common and ethylene is prevalent in distribution centers and retail
display areas. It appears that the primary ethylene problems are occurring
during shipping and in distribution centers or that sensitive varieties
are producing damaging ethylene levels internally due to vibration during
transport and handling, injury due to sleeving and boxing or darkness. Personal
interviews and discussions with major flowering potted plant growers throughout
the U.S. indicated that ethylene injury was the primary physiological cause of
returns, claims and loss of marketability for a wide range of flowering potted
plants. In writing the "Postproduction Handling of Flowering Potted
Plants" chapter for the Ball Red Book (being published this summer),
literature searches revealed a much larger number of flowering potted plants
sensitive to ethylene than previously recognized by most growers or retailers
(the chapter contains a multi-page listing of ethylene sensitive crops). In an
effort to alert the industry to these new results, the chapter contains some of
the initial research results from this project on ethylene injury of flowering
potted plants.

In the first year of this project, we have been demonstrated
the 1) ethylene sensitivity of potted rose varieties and kalanchoe varieties; 2)
value of gassing plants with EthylBloc; and 3) length of time EthylBloc is
effective on these crops (Separate Report provided). These results will be
valuable to growers in selecting varieties that are very sensitive to ethylene;
to breeders in developing new varieties with ethylene tolerance and 3) to
biotechnology programs striving to develop ethylene insensitive varieties.

Is information of this nature really valuable to the
industry? Over the last 15 years, support from AFE and the industry has allowed
us to identify varieties tolerant to postproduction problems (similar to this
research on ethylene sensitivity) — we have used this information to work with
breeders and growers to solve these problems for the industry. Specifically, a
similar approach has been taken to resolve the following problems in the
industry:

• Leaf drop in poinsettias. Research showed the variation of leaf yellowing
  in poinsettia varieties. (1983 – 92: Result - Ecke Ranch released Freedom
  to eliminate this problem);
• Leaf yellowing of potted chrysanthemum (1985 – 95 Result: Yoder Brothers
  included postproduction longevity among the criteria for variety release and
  evaluated every variety for postproduction performance):
• Bract edge burn in poinsettia (1983 – 95: Result – Ecke Ranch and
  Fischer USA submit potential varieties to our postproduction evaluation
  practices prior to release);
• Bract fading and transport tolerance (1992 – present – Result: Ecke
  Ranch requested that we incorporate vibration into our postproduction
  evaluations in order to demonstrate bract bruising differences between
  varieties).

ALL previous research was conducted in an ethylene-free
environment (poinsettias and chrysanthemums are not sensitive to external
ethylene). The current research provides new information on ethylene sensitivity
and allows for the same level of success in postproduction handling as has been
achieved with the postproduction problems mentioned above. Equally important,
this research allows for the selection and use of varieties highly tolerant to
ethylene, thus reducing the use of additional chemicals to enhance
postproduction performance. These results will save growers and retailers
significant amounts of money through proper variety selection and will give the
consumer longer lasting flowering plants! In one of our first efforts to enhance
postproduction research of flowering potted plants, we demonstrated that
flowering potted chrysanthemum longevity varied from 13 – 28 days due just to
variety selection. One interiorscaper in the St. Louis area said that in using
these data, he saved $10,000 for his company in the first 6 months in which he
applied this information to variety selection for interiors. The current data
will provide similar value to the industry.

The talks and publications resulting from this research
program on flowering potted plant longevity are included as part of the special
report.