Table of Contents
Armitage, A.M. 1990. New herbaceous ornamental crops research. p. 453-456.
In: J. Janick and J.E. Simon (eds.), Advances in new crops. Timber Press,
New Herbaceous Ornamental Crops Research
Allan M. Armitage
- UNIVERSITY OF GEORGIA SYSTEMS APPROACH TO NEW CROP EVALUATION
- SPECIFIC RESEARCH TOPICS
- Flowering Physiology
- Gas Exchange
- Growth Regulators
- Shading (Field Flowers)
- Table 1
- Fig. 1
A great deal of interest in new floricultural crop research has occurred in
recent years. The conferences in Davis, California, 1986 (Criley 1987) and
Aarslev, Denmark. 1988 provided new and exciting avenues of study In general,
three basic areas of research are presently being conducted in herbaceous
ornamental crops around the world (Armitage 1987a). The first area consists of
cultivar research in well-established ornamental species (type I species). For
example, research evaluating new inflorescence shapes of Dendranthema
grandiflora Tzvelev., new flower colors of Petunia xhybrida
Vilm. or leaf varigation patterns of impatiens fall into this category. The
second area deals with new uses for well known minor crop species (type II
species). Examples include investigations into species of Aquilegia L.,
Armeria maritima Willd., Calendula officinalis L., and
Capsicum annuum L., well known garden species, as potted plants. The
third area of research involves development and evaluation of species about
which little or no information concerning flowering physiology or performance
under production conditions exists (type III species). The use of
Melampodium paludosum L., Trachelium caeruleum L. or
Cedrela sinensis Juss. as pot plants falls under this type of
research as do investigations into Achillea x `Coronation Gold',
Caryopteris incana Miq. or Oxypetalum caeruleum Decne. as field
grown cut flower crops. The greatest amount of prior selection occurs with
type I species, followed by type II while little, if any, selection has taken
place in type III species. The grouping of species is dynamic and in a
constant state of change. As type III species become accepted in the
floriculture trade, they are relegated to type II or type I species. Examples
of new crop species are listed in Table 1.
The potential for basic research is rich for type II and III species. Little
is known concerning the control of flowering in these species and fruitful
areas of investigation might include gas exchange, photoperiod manipulation,
carbon partitioning, and factors affecting the onset of flowering. Information
pertinent to commercial use, however, such as height control, irradiance
levels, optimum temperatures and propagation techniques must also be understood
before industry accepts a new species. In the case of cut flowers, the
influence of spacing, shading, fertility and planting time on yield and shelf
life may be exciting directions for research.
Little funding is available in the United States for new crop research in
floriculture and scientists must balance fundamental studies on flowering
physiology with applied applications to industry.
The University of Georgia New Crops Program involves research on type II and
type III species in two facets of floriculture: new pot plant crops for the
greenhouse and new cut flower crops for the field. An enormous number of
species exist with potential as new crops in one or both of these areas. The
dilemma of the scientist is to not overlook potential successful species while
at the same time ignoring or discarding those with little chance for
acceptance. Therefore, a new crop program must have a system to choose species
for research and to evaluate and develop information on those selected
(Armitage, 1986). The most fundamental aspect of any system is that it be
capable of quickly discarding species from the program. The systems approach
used at Georgia has a number of places where the decision to terminate research
on a species may be made (Fig. 1). The primary objective of our program is to
develop information on crops with the following characteristics:
Potted plants must have at least 1 week shelf life without addition of
extending sprays; cut flowers, 5 days without silver thiosulfate (STS). Floral
preservatives are used in the case of cut flowers. If the shelf life is less
than this standard, the decision may be made to terminate the species or to
determine methods to extend shelf life.
The time from propagule (cutting or seed) to flower for pot plants must be less
than 20 weeks. Many species occur for which rapidly flowering cultivars may
one day be developed, however, there is little chance of commercial acceptance
if greenhouse production time results in excessive cost of production. The
program in Georgia is not in the position to spend the time necessary to breed
and select new cultivars. The additional time required for slow flowering
species detracts from other species to be investigated. If flowering time is
felt to be too long, work on the species is terminated.
Exceptions may be made with species of outstanding potential such as Eustoma grandiflorum (Raf.) Shinn. In these cases, production partitioning within
the industry will evolve. That is, propagation and growing occurs at one site
while forcing into flower occurs at another. In this instance, it behooves the
scientist to similarly partition his research on the species.
Species must be relatively tolerant of "normal" pests and diseases.
Introducing species particularly attractive to whiteflies or highly susceptible
to Botrytis should be avoided. If species being tested show weakness to
diseases and pests, work may be terminated.
The new species should not have a deleterious effect on established commercial
species. For example, our work with unproved cultivars of Primula
obconica looked promising; however, the species contains primin and results
in dermatitis in a small percentage of people. The adverse effects of primin
could adversely affect sales of all primula species, particularly P.
acaulis. Thus, the work was terminated.
Although the system provides objectivity, decisions to terminate are at the
discretion of the scientist. Thus, the scientist in charge needs to work
closely with industry.
Salvia leucantha. Plants are SD with a critical photoperiod of 12 hours
for macrobud development and 10 hours for subsequent flower development.
Approximately 14 cycles are necessary for initiation but 42 cycles are needed
for normal anthesis and raceme elongation (Armitage and Laushman 1989).
Trachelium caeruleum. Plants are LD with a minimum of 14 hours for
flower initiation but day neutral for subsequent flower development (Armitage
Pentas lanceolata. Plants are quantitative LD, flowering 7-10 days
earlier than SD (Armitage 1988a).
Oxypetalum caeruleum is day neutral for flowering but significant
internode elongation occurs with LD (Armitage et al. 1990).
Trachelium caeruleum. Light compensation and light saturation are
approximately 15 and 600 µmoles s-1 m-2 respectively at 25°C. At
saturation, net photosynthesis is 10-12 mg CO2 dm-2 h-1 (Armitage, 1988b).
Oxypetalum caeruleum. Light compensation occurs at 25 µmoles s-1 m-2
and saturation at 700 (Armitage et al. 1990).
Height controlHeight regulation studies with Melampodium paludosum,
Pentas lanceolata (Armitage 1988a), Calendula officinalis (Armitage
et al. 1987), and Trachelium caeruleum (Armitage 1988b) have indicated
that these crops may be useful for commercial pot plant production.
Fruit ripeningUse of 150-300 ppm of 2-(chlorethyl) phosphonic
acid resulted in accelerated ripening of fruit of Capsicum annuum under
greenhouse conditions (Armitage 1989a). Concentrations of 75 ppm was less
effective and 600 ppm resulted in phytotoxicity.
Studies on spacing were conducted with Achillea x 'Coronation Gold',
Physostegia virginiana Benth. and Salvia leucantha as field grown
cut flowers. Yield per plant increased as spacing increased but yield per area
decreased (Armitage 1987b).
Anemone coronaria L. Stem length increased significantly under 55%
light reduction compared with ambient (Armitage and Laushman, 1990).
Echinops ritro L., Eryngium planum L. Reduction of ambient light
resulted in increased stem lengths for both species. Yield of Eryngium
decreased with 55% light reduction, however, yield of Echinops,
increased significantly. Additional shade reduced yield of both species.
Species with increased shelf life from dips with sodium silver thiosulfate
(STS) include Anemone coronaria, Physostegia virginiana and
Optimum time of bulb planting was determined for Acidanthera bicolor
Hochst., Anemone coronaria, Brodiaea laxa Engler, Allium
sphaerocephalum L., Polianthes tuberosa L. and Liatris
spicata Willd. Perenniality and yield response was determined over a
3-year-period (Armitage and Laushman, 1990).
New crops are the lifeblood of the floriculture industry. New cultivars of
established crops have historically kept the industry strong but entirely new
crops must be introduced continually to maintain consumer interest. Research
on new crops is necessary to provide information to control flowering time,
manipulate plant size, and provide repeatable schedules. However, far more
potential species exist than can be evaluated and developed. A systems
approach to new crop research is essential in order that limited resources are
- Armitage A.M. 1986. Evaluation of new floricultural crops: a systems approach.
- Armitage A.M., B. Bergmann, and E.L. Bell. 1987. Effect of daminozide and light
intensity on growth and flowering of calendula as a potted plant. HortScience
- Armitage A.M. 1987a. What is a new crop. Acta Hort. 205:1-2.
- Armitage A.M. 1987b. The influence of spacing on field-grown perennial crops.
- Armitage A.M. 1988a. Influence of photoperiod, supplemental light, and growth
regulators on growth and flowering of Pentas lanceolata. HortScience
- Armitage A.M. 1988b. Effects of photoperiod, light source, and growth
regulators on growth and flowering of Trachelium caeruleum. J. Hort Sci.
- Armitage A.M. 1989a. Promotion of fruit ripening of ornamental peppers by 2
(chloroethyl) phosphonic acid.
- Armitage A.M. 1989. Promotion of fruit ripening of ornamental peppers by
ethephon. HortScience 24:962-964.
- Armitage A.M. and J.M. Laushman. 1989. Photoperiodic control of flowering of
Salvia leucantha L. J. Amer. Soc. Hort. Sci. 114:755-758.
- Armitage, A.M. and J.M. Laushman. 1990. Planting date and in-ground time affect
yield and quality of field grown bulb crops. 1. Acidanthera, Anemone,
Allium, Brodiaea and Crocosmia. HortScience (in press).
- Armitage, A.M., Seager, N.G. Warrington and I.L. Greer, D. H. and J. Reyngold
1990. Response of Oxypetalum caeruleum to irradiance, temperature and
photoperiod. J. Amer. Soc. Hort. Sci. (in press).
- Criley, R.A. (ed.) 1987. Symposium on the development of new floricultural
crops. Acta Hort. 205.
Table 1. Potential species for pot and cut flower culture for new crop
Type I. (Species well established as ornamental plants)
Type II Species (New uses for well known minor crops)
- Greenhouse pot plants
- Bedding plants (in general)
- Begonia x hiemalis
- Denthanthema grandiflora Tzvelev.
- Dianthus caryophyllus L
- Euphorbia pulcherrima Willd.
- Exacum affine Balf.
- Kalanchoe blossfeldiana Poellnitz
- Lilium longiflorum Thunb.
- Pelargonium x hortorum Bailey
- Sinningia speciosa Benth & Hook.
- Greenhouse Cut Flowers
- Antirrhinum majus L.
- Dendranthema grandiflora Tzvelev.
- Dianthus caryophyllus L.
- Gerbera jamesonii Bolus.
- Rosa x hybrida
- Field Cut Flowers
- Achilles filipendulina Lam.
- Delphinium sp.
- Gypsophila paniculata L.
- Iris sp.
- Iris xiphium L.
- Limonium sinuatum Mill.
Type III Species (little information available)
- Greenhouse Pot Plants
- Alstroemeria aurantiaca D. Don.
- Aquilegia x hybrids
- Armeria maritima Willd.
- Astilbe x arendsii
- Bouvardia longiflora HBK.
- Calendula officinalis L.
- Campanula carpatica Jazq.
- Capsicum annuum L.
- Eustoma grandiflora (Raf.) Shinn.
- Fressia x hybrids
- Lilium x hybridum
- Zantedeschia aethiopica Spreng.
- Pot Plants
- Allium neapolitanum Cyr.
- Alonsoa warscewiczii Regel.
- Cedrela sinensis Juss.
- Coprosma x kirkii Cheesem.
- Hebe speciosa Cockayne & Allan
- Ixora coccinea L.
- Melampodium paludosum L.
- Nerine sarniensis (L.) Herb.
- Pentas lanceolata Schum.
- Reinwardtia indica Dumort
- Rhodohypoxis baurei (Bak.) Nel
- Tibouchina semidecandra Aubl.
- Trachelium caeruleum L.
- Veronica longiflora L.
- Cut Flowers Field or Greenhouse
- Achillea x 'Galaxy Series'
- Achillea x 'Coronation Gold'
- Acidanthera bicolor Hochst.
- Allium giganteum L.
- Anemone coronaria L.
- Anigozanthos mangleslii D. Don
- Brodiaea (Triteleia) laxa Benth.
- Caryopteris incana Miq.
- Centaurea americana Nutt.
- Centaurea macrocephala Puschk.
- Centaurea moschata L.
- Chamelaucium uncinatum Schauer.
- Consolida ambigua (L) P. W BallaHeyw.
- Craspedia globosa G. Forst.
- Crocosmia crocosmiiflora N.E. Br.
- Echinops ritro L.
- Emilia javonica Cass.
- Eryngiun alpinum L.
- Eryngium planum L.
- Euphorbia fulgens Karw.
- Euphorbia marginata Pursh.
- Gomphrena globosa L.
- Herbs (e.g. Foeniculum)
- Hypericum androsaemum L. (fruit)
- Limonium spp. (many)
- Nerine sarniensis (L.) Herb.
- Nigella damescena L. (fruit)
- Ornithogalum spp.
- Physalis alkekengi L. (fruit)
- Physostegia virginiana Benth.
- Polianthes tuberosa L.
- Salvia leucantha Cav.
Fig. 1. Systems approach to crops research at University of Georgia New
Crops Program (from Armitage 1986).
Last update September 4, 1997