Table of Contents
Roh, M.S. and R.H. Lawson. 1990. New floricultural crops. p. 448-453. In:
J. Janick and J.E. Simon (eds.), Advances in new crops. Timber Press,
New Floricultural Crops*
Mark S. Roh and Roger H. Lawson
- THE NEW CROPS PROGRAM
- Production-Nationwide Evaluation
- Schedule for Production Trial
- Pre- or Post-production Physiology
- Distribution of Plant Material and Release of Cultural Information
- Consumer Education
- FINANCIAL SUPPORT
- RESEARCH RESULTS
- LIST OF NEW CROPS FOR EVALUATION
- Pot Plants
- Cut Flowers
- Bedding Plants
- Fig. 1
The definition of new crops can be: a newly discovered genera or species; newly
introduced cultivars of plants grown in earlier years, but forgotten or without
complete cultural information; plants that are cultivated in foreign countries
but have not been introduced in the United States; or crops that can be
produced with new production technologies that can enhance crop quality and
shorten the total production time.
New crops research programs in The Netherlands (Noordegraaf 1987) and Denmark
(Christensen and Fries 1987) have expanded the range of new plant materials
available in the European market. A similar program was initiated for the
United States (Armitage 1986, Roh and Lawson 1987b). Introduction of new crops
requires identification, exploration and collection of new plants (Klougart
1987), with interesting characteristics that may be economically important.
Hybridization and selection from a breeding (Wilfret 1987) program or
introduction of new cultural technology (Noordegraaf 1987, Roh and Lawson
1987b) are important steps in the introduction of a new crop. To meet the
increasing demand by growers and consumers for new crops in the U.S., the
Florist and Nursery Crops Laboratory initiated a program of germplasm
development in 1982. A cooperative agreement was signed between the American
Floral Endowment, the Society of American Florist (SAF), and the USDA in 1984
to provide additional financial support for the program.
The overall scheme is diagrammed in Fig. 1.
The Laboratory collection includes many genera or species of native Australian
plants including Correa, Chamelaucium, and Anigozanthos
(kangaroo paw); Gesneriaceae such as Achimenes and Columnea from
specially growers; Centradenia and Coprosma from Denmark; and new
cultivars of Eustoma and Clematis for pot plant culture from
Japan. When certain genera and species are identified as potential new crops,
additional species or cultivars are secured to increase the germplasm base.
This is important since selections or hybrids from one area of the world may
not have the same requirements for flowering as plants of the same genus
developed at other locations. For example, two clones of Reinwardtia
indica have different critical photoperiods for flower induction
Generally less than 10 propagules are collected and it takes approximately a
year to build enough stock plants for the initial experimentation. During
propagation and early growth and development, the rate and the ease of
propagation as well as plant statue are evaluated. Observations are made on
the compact and dwarf appearance of plant, time of flowering, and
susceptibility to disease. Care must be taken not to eliminate potentially
important germplasm. Flowering may be erratic under natural greenhouse growing
conditions, and further evaluation may require controlled light and temperature
studies. For example, Aeschynanthus speciosus Hook. does not flower
uniformly and extensive research was required to determine factors necessary
for uniform and controlled flowering in year-round production (Gertsson 1987,
Roh et al. 1988, Welander 1984).
Following propagation and an initial period of observation, investigations of
growth media/nutrition, growth regulator treatments, and light and temperature
effects are initiated. A major factor to consider while assessing production
capability is the forcing period. From the time the grower places the rooted
plant in the greenhouse bench, a maximum production time of 18 weeks will allow
a turnover of three to four crops a year. Should the plant be excluded if more
than 18 weeks are required? The total production time of Eustoma grandiflorum Griesb. from seed sowing to flowering requires about seven
months (Halevy and Kofranck 1984, Roh and Lawson 1984a, Tsukada et al. 1982).
On the basis of cropping time, Eustoma might be excluded from the
program, although post-production longevity is excellent. However, plug
production technology has enabled greenhouse growers to shorten cropping time
to 15 to 17 weeks (Roh and Lawson, 1984a).
After an initial production trial in the laboratory, cultural information is
released (Griesbach 1985, Lee et al. 1988, Roh and Lawson 1984a, b, 1987b).
Evaluation of the same production protocol is then tested at various locations
under diverse environmental conditions. Development of a systematic and well
coordinated national program on the new crop project is vital for the success
of the total introduction program. The nationwide system described by the
Florist and Nursery Crops Laboratory for new crop introduction requires support
from all sectors of industry and from research scientists. Based on the
criteria for selection and the nationwide evaluation program, recommendations
can then be made for production of specific cultivars in different areas of the
The time required for a regional and national production trial may vary
depending on the nature of the new crop. The time required also depends on the
extent of the information to be developed. We project a maximum of five years
if a plant, like Eustoma, is relatively new or has not been investigated
extensively A maximum of two to three years may be sufficient for crops like
Coprosma and Cupressus that have been commercialized on a limited scale
or previously introduced in other countries.
Post-production physiology can be an important factor in determining which
plants should or should not be maintained in the program. However, the
post-production characteristics cannot be used to screen the plant material at
the beginning of the program. Coprosma 'Coppershine' initially showed an
undesirable yellowing and shedding of leaves, but by maintaining a tissue
nitrogen content higher than three percent, plants can be transferred from a
greenhouse to a home environment without acclimatization. Tiny flower buds of
Eustoma will not open on stems after harvest nor will a full purple or
pink color develop when cut stems or potted plants are placed in a low-light
intensity. This problem requires further study to extend useful
post-production life of the crop.
Following the research phase, a potential new crop is distributed to selected
growers in the United States so that the plants can be tested and evaluated
under commercial conditions. Plant material is distributed to the cooperators
with complete instructions on how to handle the crop for proper evaluation.
Cultural and handling information is then published in grower periodicals.
Examples include articles on Gerbera (Roh and Lawson 1984b),
Eustoma (Roh and Lawson 1984a), Anigozanthos (Roh and Lawson
1987a) and Phalaenopsis orchid 'Toyland' (Griesbach 1985, Lee et al.
1988). Research results, displays of plant material and posters are also
presented at growers meetings and trade shows.
At the time of the introduction of plant material and cultural information,
consumers and the general public must be informed of a planned new crop
introduction. Growers, wholesalers, and retailers should all receive advance
information prior to introduction. If consumers are not properly informed by
the retailer at the end of the marketing channel or by other media sources, the
demand at the time of an introduction may be so low that the new plant may be a
disappointment to the grower, and the economic potential of the crop may not be
New crops research in the Florist and Nursery Crops Laboratory was initiated
with support from the USDA Small Farms Program and by a grant from the Fred C.
Gloeckner Foundation in 1982. In 1984, the program was expanded with a
contribution from industry members of the SAF and the SAF Growers Division
through the American Floral Endowment. The annual contribution from industry
is matched by the Administrator of the USDA, Agricultural Research Service.
Program sponsors from industry have formed an advisory committee that assists
in locating and securing new plants, suggests research directions, and aids in
market analysis for the new plant material to be released. The advisory
committee meets twice a year, once at Beltsville to observe new plant material
and advise in the selection of plant candidates for further experiments. The
advisory committee members are given up-to-date information on new plant
material collected and results of past research.
Eustoma grandiflorum Griesb. Seed propagation (Tsukada et al.
1981) is the best method to start a crop although tissue culture (Semeniuk and
Griesbach 1987) and rooting of cuttings (Roh et al. 1986a) are also possible.
Seeds germinate within 15 days at 25°C. During the first 60 to 90 days
after germination, temperatures above 25°C should be avoided to prevent heat
stress. The optimum temperature is considered near 10° to 15°C.
Seedlings should be transplanted before the stem elongates, and root
disturbance should be minimized to prevent wilting when the plants show visible
buds. More than 60 days of 16 hours of long days are required to accelerate
flowering by about 15 to 25 days (Tsukada et al. 1981).
Most commercial cultivars are tall, cut flower types that require the
application of growth retardants for pot plant production (Roh and Lawson
1984a, Tjia and Sheehan 1986). In the Florist and Nursery Crops Laboratory,
genetic dwarf selections were obtained from tissue culture and multiplied
through seed propagation without losing the dwarf characteristics (Griesbach et
Chamelaucium uncinatum Schauer. Stem tip cuttings are propagated
between October and May without difficulty. Rooting hormone, rootone or
1600-3000 ppm IBA treatments enhance rooting of the cuttings (Whitton et al.
1988). Rooted plants grow slowly and may require up to 4 to 5 months before an
inductive treatment for flowering can be given. Liquid feeding at 200 to 400
ppmN or one gram of slow release fertilizer such as 14N-6P-8K Osmocote per 10
cm pot will ensure optimum vegetative growth. When shoots are 5 cm long, 40
days at 18° to 20°C with 10 hours of short day or 3 to 4 weeks of 8 hours
of short day at 24deg./16deg.C initiated flower buds (Shillo et al. 1985).
Keeping quality as a pot plant is excellent.
Correa 'mannii' Andr. Stem tip cuttings root
easily with 1500 ppm IBA treatment. Nutrition requirements are similar to
Chamelaucium However, Correa is a long day plant requiring at
least 40 days of 16 hours of long days at 18°C. Keeping quality as pot
plant is good, lasting about 20 days after anthesis.
Achimenes and Achimenantha. Selected Achimenes
longiflora D.C. hybrids and one Achimenantha hybrid were evaluated
for forcing during winter. Due to a dormancy that lasts more than 3 months in
Achimenes, and 5 months in Achimenantha, tissue culture
propagation was employed to maintain stock plants. Scale pieces were
successfully used as an explant source, and flowering plants were obtained in
80 to 100 days, depending on the season, without mutation (Roh and Wocial
1988). To avoid dormancy (Deutch 1974), rooted cuttings should be forced with
16 hours of long days from high irradiant discharge lamps.
Gerbera jamesonii Hook. Tissue culture and seed propagated
gerbera selections were evaluated. Gerbera required 8 to 12 hours of
photoperiod at 15° to 18°C for 40 days to promote flowering (Roh and
Lawson 1984b). Some Happipot strains did not require short days. Seed gerbera
require higher temperatures (21°C) and possibly short days to increase the
number of flowers. Osmocote and liquid fertilizer treatments are required for
quality crop production.
Aeschynanthus speciosus Hook. Techniques for year-round
flowering of Aeschynanthus speciosus and hybrids are being investigated.
Rooted cuttings of Aeschynanthus speciosus, flowered when rooted
cuttings were obtained from stock plants grown with a high nutritional regime
(Roh et al. 1988). Some other hybrids flowered earlier under high temperature,
long day, and high light intensity conditions (Gertsson 1987, Welander 1984,
Zimmer 1972). Recent studies indicate that rooted cuttings from stock plants
grown at 18deg./17°C day/night, flowered earliest as compared to higher
Anigozanthos. Kangaroo Paw is propagated by tissue culture or
division (Ellyard 1978). Young plants should be grown at least 8 weeks out of
tissue culture before an inductive treatment for flowering is given. Some
selections do not require low temperature treatments, 13°C for 6 to 8 weeks,
although most of the hybrids tested require low temperature treatments for
flowering (Roh and Lawson 1987a). When the temperature is higher than 21°C,
flowering is completely inhibited when plants are grown under short day
conditions. Some flowering occurs under long day conditions, even at
temperatures above 18°C. Temperature is a controlling factor for flowering
(Motum and Goodwin 1987).
Lilium elegans Thunb. Research has focused on flower bud
initiation and development. Flower bud initiation is completed within 3 to 21
days after the completion of a cold treatment (Pergola and Roh 1987).
Immediately after cold storage, temperatures higher than 21°C should be
avoided to prevent bud abortion and blast (Roh et al. 1986b). The optimum bulb
cold treatment varies according to the cultivar. Other research involves
development of cultural technologies to produce commercially acceptable
flowering plants within 10 months starting from small bulblets or bulbils
weighing less than 500 mg.
The following taxa or new hybrids are under evaluation or collected for
propagation and test as pot plants, cut flowers and bedding plants.
Abutilon hybrids (Malvaceae, Flowering maple)
Astilbe hybrids (Saxifragaceae)
Clematis hybrids (Ranunculaceae, Clematis)
Erica spp. (Ericaceae, Heath)
Exacum macranthum hybrid (Gentianaceae, Perisian violet)
Leptospermum spp. (Myrtaceae)
Passiflora hybrids (Passifloraceae, Passion flower)
Sinningia cardinalis (Gesneriaceae)
Vallota speciosa (Amaryllidaceae, Scarborough lily)
Eucrosia bicolor Ker Gawler (Amaryllidaceae)
Cuphea hybrids (Lythraceae, Cuphea)
Gentiana hybrids (Gentianaceae)
Pentas lanceolata Benth. (Rubiaceae)
Zauschneria californica Presl. (Onagraceae, California fuschia)
New crops research is dynamic and the interest in new crops is rapidly
expanding among scientists, growers, and the general public. Each of the steps
described in this article from the identification of new plant material with
potential commercial value to its release with cultural information is
important for the successful introduction of a new plant.
The program at the United States Department of Agriculture is a joint venture
between the floral industry and the government. Systematic evaluation
procedures with university and industry sponsors are designed to produce
complete cultural information that can be utilized nationwide. This research
program is an example of how government and industry can work together and how
production technology can be developed with close communication and cooperation
among individuals representing various geographical areas and interests.
- Armitage, A.M. 1986. Evaluation of new floricultural crops: A system approach.
- Christensen, O.V. 1988. Growth and flowering of two clones of Reinwardtia
indica at different temperature and daylength. First International
Symposium on the Development of New Floricultural Crops. Faaborg, Fyn, Denmark.
- Christensen, O.V., and K. Fries. 1987. Research and development of unknown pot
plants. Acta Hort. 205:33-37.
- Deutch, B. 1974. Bulblet formation in Achimenes longiflora. Physiol.
- Ellyard, P.K. 1978. In vitro propagation of Anigozanthos manglesii,
Anigozanthos flavidus, and Macropidia fuliginosa. HortScience
- Gertsson, U.E. 1987. Influence of light on flowering in Aeschynanthus
speciosus. J. Hort. Sci. 62:71-74.
- Griesbach, R.J. 1985. An orchid in every pot. Florists' Rev. 176(4548):26-27,
- Griesbach, R.J., P. Semeniuk, M. Roh, and R.H. Lawson. 1988. Tissue culture in
the improvement of Eustoma. HortScience 23:658,791.
- Halevy, A.H., and A.M. Kofranek. 1984. Evaluation of lisianthus as a new
flower, crop. HortScience 19:845-847.
- Klougart, A. 1987. Exploration, adaptation, evaluation, amelioration. Acta
- Lee, J.S., M.S. Roh, R. Griesbach, and K.C. Gross. 1988. Effect of temperature
and light intensity on growth of Phalaenopsis, 'Toyland' orchid.
HortScience 23:500. (Abstr.)
- Motum, G.J. and P.B. Goodwin. 1987. The control of flowering in Kangaroo paw
(Anigozanthos spp.). Scientia Hort. 32:123-133.
- Noordegraaf, C. vonk. 1987. Development of new cutflower crops. Acta Hort.
- Pergola, J, and M.S. Roh. 1987. The relationship between flower bud initiation
and respiration in Asiatic hybrid lily bulbs. Acta Hort. 205:241-247.
- Roh, M.S., J.D. Cohen, and K.C. Gross. 1986a. Vegetative propagation of
Eustoma grandiflorum under mist. HortScience 21:799. (Abstr.)
- Roh, M.S., K.C. Gross, and A.E. Watada. 1986b. Bud abscission of the Asiatic
hybrid lily 'Red Carpet'. HortScience 21:1659. (Abstr.)
- Roh, M.S., and R.H. Lawson. 1984a. The lure of lisianthus. Greenhouse Manager 2
(11):103-104, 108, 110, 112-114, 116-121.
- Roh, M.S, and R.H. Lawson. 1984b. The graces of gerberas. Greenhouse Manager 3
(6):79, 82, 86-88, 90, 92, 94-95, 98, 100.
- Roh, M.S., and R.H. Lawson. 1987a. Kangaroo-paws, a classy new floral
experience. Greenhouse Manager 5(9):86-87, 90, 92, 96-97, 97-100, 103, 105,
- Roh, S.M., and R.H. Lawson. 1987b. Research and development on new crops in the
United States Department of Agriculture. Acta Hort. 205:39-48.
- Roh, M., B. Whitton, and W. Healy 1988. Interaction of propagation method and
nutrition on flowering of Aeschynanthus speciosus Hook. HortScience
- Roh, M.S., and M. Wocial. 1988. In vitro production of
Achimenantha 'Inferno' as influenced by season and the source of the
explants. First International Symposium on the Development of New Floricultural
Crops. Faaborg, Fyn, Denmark. (Abstr.)
- Semeniuk, P., and R.J. Griesbach. 1987. In vitro propagation of prairie
gentian. Plant Cell, Tissue, Organ Culture 8:249-253.
- Schussler, H.K. 1984. Eustoma russelianumForsoksresultat fran Alnarp.
FAKRA/tradgard. No. 154. p. 4.
- Shillo, R., A. Weiner, and A.H. Halevy. 1985. Environmental and chemical
control of growth and flowering of Chamelaucium uncinatum Schauer.
Scientia Hort. 25:287-297.
- Tjia, B., and T.J. Sheehan. 1986. Chemical height control of Lisianthus
russellianus. HortScience 21:147-148.
- Tsukada, T., T. Kobayashi, and Y. Nagase. 1981. Studies on the physiological
characters and cultivation of prairie gentian. I. Physiological characters of
germination and raising of seedling. Bul. Nagano Veg. Ornam. Crops Expt. Sta.
- Tsukada, T., T. Kobayashi, and Y. Nagase. 1982. Studies on the physiological
characters and cultivation of Russel prairie gentian. II. Effect of temperature
and photoperiod on growth and flowering. Bul. Nagano Veg. Ornam. Crops Expt.
- Welander, N.T. 1984. Influence of temperature and daylength on flowering in
Aeschynanthus speciosus. Scientia Hort. 22:157-161.
- Whitton, B., M. Roh, and W. Healy 1988. The influence of plant growth
regulators and cutting length on rooting of Chamelaucium uncinatum
'Purple Pride'. HortScience 23:231. (Abstr.)
- Wilfret, G.J. 1987. The role of plant breeder in the evaluation and breeding of
new floricultural crops. Acta Hort. 205:13-19.
- Zimmer, K. 1972. Zum Bluhen von Aeschynanthus speciosus. Gartenwelt.
*We acknowledge the Society of American Florists, the American Floral
Endowment, the Fred C. Gloeckner Foundation and New Crops Advisory Committee,
for their financial support, Dr. R.G. Anderson, University of Kentucky, Dr. J.
Frett, University of Delaware, Dr. T. Ferriss, University of Wisconsin-River
Falls, Dr. G. Hanniford, Ohio State University, Dr. Brent Harbaugh, Gulf Coast
Research and Education Center, Dr. R. Larson, North Carolina State University,
Dr. W. Healy, University of Maryland, Dr. R. Regan and Dr. V. Walter,
California Polytechnic State University, Dr. R.E. Widmer, University of
Minnesota, and Dr. G.J. Wulster, Rutgers University for cooperative
|Fig. 1. Overall scheme of the new crops evaluation system.
September 4, 1997