Publication of work funded by the Australian Flora Foundation:

Lacey, S. 1989. ‘Selection of Helichrysum diosmifolium for cut flower production’. Proceedings of the WA Department of Agriculture Conference ‘The Production and Marketing of Australian Flowers’. Perth 13-14 July 1989. pp 1-3.   Grant details

SELECTION OF HELICHRYSUM DIOSMIFOLIUM FOR CUT FLOWER PRODUCTION
Sandra Lacey
Dept of Primary Industries, Queensland

Introduction
Helichrysum diosmifolium is a perennial shrub which occurs naturally throughout the eastern mainland states of Australia. It is commonly known as rice (or sago) flower due to the grainlike appearance of the flower heads which are picked in an immature state. When the flowers are fully open they have the typical Helichrysum appearance but unfortunately at this stage they shatter very easily and cannot survive harvesting and marketing. Colour forms range from white to dark pink and red has been reported. However, the pink colour usually only occurs on the outermost bracts and thus appears to fade as it becomes less conspicuous as the flower bud expands.

H. diosmifolium is currently used fresh as a filler in mixed bunches or sold dried after being dyed the full range of colours including blue, green or purple. It is presently available over a relatively short period of six to eight weeks in late winter and spring in Queensland and spring to early summer in New South Wales. Until recently this flower was cut exclusively from natural stands.

Initial attempts to cultivate rice flower as a crop have had limited success as unsuitable forms of the species were used and no forethought was given to its post-harvest requirements. This experience indicates how premature promotion by entrepreneurs can damage the reputation of a potential crop to both growers and the export market.

After a heavy promotion, a number of growers set up plantations of rice flower and some shipments were sent to the United States where considerable interest had been shown in the crop. Unfortunately, these consignments were condemned due to blackening of the foliage rendering them unsaleable. This problem appears to be physiological in nature but has not yet been satisfactorily resolved.

The other problem encountered by these growers was that they were sold a form which was cream in colour and probably more suited as a garden shrub rather than a cut flower.

Objectives
The aim of this project is to collect H. diosmifolium for the selection of types most suitable for cultivation. Selection is being made mainly on the basis of flower form and colour, and time of flowering.

Two separate types of stem form are seen as being desirable. Stems with flowers arranged in a flat topped head are suitable for mixed bunches, while a finer 'bushier' spray seems more suited to the dried market.

Flower colour is an obvious basis for selection. A pure white colour is in general more highly desirable than the off-whites or creams, both as fresh colour and as a background for dyeing. Many of the cream shades take on a muddy tinge as the flower matures.

Selection for variation in time of flowering is of particular importance to extend the time of flower availability. The relatively short flowering season of this plant puts it at a definite marketing disadvantage, particularly when continuity of supply is crucial.

Strategy
The locations of all known sites of collection of H. diosmifolium in Queensland were obtained from the Queensland Herbarium. Based on this information, collecting trips were made to the districts of Dalby, Chinchilla, Roma, St George, Kingaroy, Crows Nest, Stanthorpe and the Brisbane Valley. Material was collected from over eighty sites. In some locations the species was present in quite dense stands stretching up to 1 km along the roadside while at others single plants occurred in isolation with many kilometres between plants. At each site, cutting material was taken from plants which had superior flower colour or stem form, or had a different flowering time to the rest of the plants in the stand. In addition to this, seed was collected randomly from plants throughout the population.

This material was propagated and planted at Redlands Research Station for evaluation. The first field plantings were made in May 1988.

As a result of the unusually mild and wet conditions that winter, both cultivated plants and those in natural stands flowered early. There was a good range of flower colour from pure white to pink, but no evaluations on flower form could be made due to the small plant size and early flowering. However it is obvious that a high degree of variability exists within the species with regard to horticultural desirability.

General Notes on Collection
When accessing Herbarium information it is very important to retrieve the year of collection as well as the locations, as land usage can change markedly over the years and the natural vegetation may no longer exist even on roadsides. In areas where broadacre cropping is practiced and roads are unfenced, the likelihood of finding anything may be remote unless the sighting was a recent one. Palatability to livestock also bears considering. Excessive browsing by stock can be a problem as it can dramatically alter plant form and vigour and consequently flower characteristics.

There may be limited value in selecting on the basis of plant form in the wild. The cultivated plants show much more vigorous growth and dense foliage than the specimens from the bush form which the cuttings and seeds were taken.

The effect of season cannot be underestimated. Return collecting trips were made in the flowering season of the following year (1988) to the Dalby and Stanthorpe districts where some of the most interesting selections were found. In some cases there were marked differences in the plant populations between the two years.

Acknowledgement
Funding for this collection work was obtained from the Australian Flora Foundation. This assistance is gratefully acknowledged.