Agriculture Reference
In-Depth Information
19.5). The purchaser who bids first obtains the consignment.
Despite the traditional and general popularity of central
market systems, direct sourcing of cut flowers is practised
widely. Thus, large volumes of cut flower lines used in
bouquets are obtained directly from growers. Wholesalers
that prepare bouquets typically mix-and-match component
flower types to achieve a colour or seasonal theme at an
agreed price and with a vase life guarantee of one or two
weeks. High volume retail outlets include supermarkets,
petrol stations and cut flower stands. The use of refrigerated
display areas or cases helps to slow cut flower development
and senescence processes. Increasingly, florists specialise
in floral art that involves a wider variety of materials than
fresh cut flowers, including dried and dyed floral material,
balloons and ribbons, and services such as greeting cards
and delivery. Internet marketing is a relatively recent and
lucrative variation of the traditional florist trade.
Table 19.9
Effects of Shallow and Deep Vase
Water on Vase Life of Leptospermum and Acacia
(Mimosa) Flowers.
Vase life (days)
Flower
Shallow water
(5 cm)
Deep water
(20 cm)
Leptospermum
obovatum
3
8
L. polygalifolium
2
7
Acacia
baileyana
7
11
Source: J.D. Faragher and V.G. Williamson
(unpublished data), and Williamson
et al
. (2002).
Table 19.10
Effects of a Selection of Germicides,
in Citrate-Glucose Solution (0.2 and 10 g/l,
Respectively), on Longevity Indices of Time to
Decline in Fresh Weight (Life) and Maximum Gain
in Fresh Weight (Gain) for Cut Rose cv. Classy.
Treatment
a
Consumption
Fresh cut flowers are often sold with ingredients (e.g.
sachets of sugar and citric acid crystals) to make up a vase
solution. Consumer advice is usually printed on sachets,
flower sleeves or labels. This advice typically covers
trimming to remove dead and damaged flowers and leaves,
and removal of leaves that will be below the vase solution
surface. Re-cutting under water to remove 2 to 3 cm from
stem ends is recommended. Other common and sound
advice includes keeping flowers in cool places, out of
direct sunlight, away from ripening fruit (i.e. sources of
ethylene) and in draught-free areas (Joyce 1986).
Life (days)
Gain (%)
Water (negative control)
7.0
5.0
Citrate-glucose (positive
control)
7.0
8.3
CPC (0.05 g/l)
9.5
5.1
Dantogard (0.05 g/l)
8.0
10.3
DICA (0.2 g/l)
8.5
5.1
HQC (0.2 g/l)
9.4
9.1
Vase life
The vase life of most cut flowers can be extended by the
use of a suitable vase solution. These are similar to the
pulsing and re-hydration solutions mentioned above. They
can be made up by the user or purchased as commercial
products.
Isocil (0.05 g/l)
9.6
8.7
Physan (0.05 g/l)
9.4
10.0
CPC = cetyl pyridinium chloride;
DICA = dichloroisocyanurate, sodium salt;
HQC = hydroxyquinoline citrate.
Source: Compiled from Knee (2000).
a
Water
The water used for vase solutions should be free of
inorganic (e.g. clay) and organic (e.g. live or dead microbes)
particles that can block transpirational water flow via the
xylem. Aluminium sulphate can be used to flocculate clay.
The use of water that is warm (40-50°C) or cold (about
2°C), deep (Valle
et al
. 2001; Table 19.9), acidic (pH 3-4)
and/or contains a surfactant (Table 19.3) can facilitate
uptake (Halevy & Mayak 1981; van Doorn 1997; Reid
2002, 2004). Fluoride in tap water at about 1 ppm can be
highly toxic to some flowers, like gerberas, gladioli,
freesias and roses (Halevy & Mayak 1981; Tjia
et al
.
1987). Using rain, deionised water or clean bore or dam
water can avoid this problem.
Microbes
Bacteria and fungi, including yeasts, proliferate rapidly in
vase solutions (Halevy & Mayak 1981; van Doorn 1997; Reid
2002, 2004). Their growth is fuelled by substrates that leak
from submerged stems. Germicides such as chlorine and
quaternary ammonium compounds are used to slow their
growth (Table 19.10). Acidification with citric acid to about
