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19. Undergraduate Students: Fourth Year (Honours) Study Projects

Development of a website for Australian Native Foods

BAppSc (Horticultural Technology)
School of Land and Food
The University of Queensland
Gatton College

An investigation of Rosemary (Rosmarinus officinalis L.) as a potential new crop in South-East Queensland.

BAppSc (Horticultural Technology)
School of Land and Food
The University of Queensland
Gatton College

This report investigates the potential of rosemary (Rosmarinus officinalis L.) as a new crop in south-east Queensland by examining marketing requirements, carrying out economic analyses and examining agronomic factors.

Depending on which of the four end products is derived from R. officinalis (fresh herb, dried herb, essential oil or potted plant), the species can be used in several different applications. A commercial evaluation of these products indicated that the dried herb form of the species was the only product with sufficient commercial value to warrant further investigation for broad-acre production.

A marketing analysis revealed that the current dried herb markets were limited. However, significant potential existed for their expansion. A gross margin calculation showed satisfactory returns (of $11,769 per hectare). This was based on manufacturing-grade herb prices for which the market is under-developed. Prices of trade herbs which showed greatest potential for current market penetration, would have fallen slightly below the break-even price.

The species is agronomically suited to the target area and crop management requirements are minimal. Limitations to any new herb growers include the lack of organisation and cohesion in the industry which is detrimental to the creation of cooperative ventures between growers. Such ventures are the only viable way a new grower could achieve success with R. officinalis on a broad-acre scale. Other options include starting small and diversifying with other herbs.

Analysis of cocoa (Theobroma cacao L.) as a potential new crop for Australia.

BAppSc (Horticultural Technology)
School of Land and Food
The University of Queensland
Gatton College

Since the late nineteenth century, Theobroma cacao L. (cacao) has been viewed as a potential commercial crop for northern Australia. Suitable sites for an industry are located in the coastal areas between Cairns and Ayr, in Queensland, and the Ord River District of Western Australia. However, no commercial cacao has yet been grown. Cost of labour has been the limiting factor. In 1991, Australia imported $60 million worth of cocoa products for chocolate production. At a current price of $2576/t of dried beans, cacoa production in Australia is not profitable.

Vegetable amaranth improvement for South Africa
(Exchange Masters student, University of the North, South Africa)

These notes have been extracted from a report prepared by Mr Mposi following his six months as a Masters exchange student at the University of Queensland Gatton College, from July to December, 1998.

The genus Amaranthus consists of nearly 60 species that can be broadly categorised into grain, green leaf vegetable, and weed types.

Amaranth is cultivated as a minor food crop in Central and South America, Mexico and parts of Asia and Africa and is extensively grown as a green leaf vegetable in many tropical countries. There is no distinct separation between the vegetable and grain type since the leaves of young grain type plants can be eaten as greens.

In Africa, Amaranthus hybridus and Amaranthus thunberghii are the species most commonly used for this purpose. They are grown occasionally by farmers in west Africa but not in southern Africa.

Amaranthus hybridus is grown for grain or vegetable production in the south-western United States, China, India, Africa, Nepal, the South Pacific islands, in the Caribbean region, Greece, Italy and Russia.

A. hybridus is fast growing, requires little cultivation, is resistant to moisture stress and produces a good yield of grain in Sorghum-like heads. However, it is a very difficult crop to seed because its grain is small and needs to be planted in a shallow seedbed to ensure germination. Since the seeds are so close to the surface, rain or irrigation can wash out recently planted fields.

There is less research on Amaranthus thunberghii. It has been classified as an aphid-trap plant and as a broadleaf weed by the commercial farmers of other crops. However, it grows very fast and is resistant to water stress. It is also tolerant to many insect pests such as aphids, fall army worm etc.

Amaranthus thunberghii has a more prostrate growth habit than its relatives and tends to be more common on roadsides and in gardens than in cropping areas.

These two species of Amaranth have not caught the imagination of the scientific research establishment in the southern African countries even though they are consumed by the rural-based indigenous people.

The genus Amaranthus consists of approximately 60 species. Only a few of these are cultivated types, while most are considered weedy species.

The origin of Amaranth is obscure. Some authors believe that amaranth originated in Central and South America because it was a staple crop of the ancient Aztec and Inca civilizations. Nigeria has also been claimed as the center of diversity, collaborated by the prevalent use of local names and the enormous genetic diversity available there.

Amaranth germplasm is available in at least eleven different countries and several thousand germplasm accessions are available in the United States.

The principal Amaranth weed, red ragwort is Amaranthus retroflexus which is considered one of the world’s most cosmopolitan weeds.

Amaranth is a C₄ plant, and this characteristic is believed to have contributed to the plant’s wide geographic adaptability to diverse environmental conditions. However in cultivation, every aspect of production requires special attention and consideration. Twentieth century Amaranth production is vastly different from that of earlier civilisations and from modern day primitive agriculture systems.

Amaranth prefers soils with pH above 6.0 and soil temperatures above 15 C for establishment. Seeding rates of 1.2 to 3.5 kg seed/ha planted to an average depth of 1.3 cm are recommended. The most accurate commercial seeding rates have been achieved by using vegetable seeders which use seed plates of appropriate size to meter the seed.

The most commonly advised fertility guide for Amaranth has been 112 to 135 kg/ha of total available N, with a soil test of 15 to 30 ppm P and 80 to 120 ppm K. Fertility needs vary significantly in higher rainfall areas.

Established plant population density has a significant effect if the amaranth is being grown for grain yield, with the highest yields achieved at the lowest populations.

Harvesting for vegetable use is usually carried out by cutting the plants above the second leaf from the ground, at a height of about 7.5 cm, after they have attained a marketable size. Cutting is done at various lengths (15 to 23 cm) in the first instance, and subsequently, branches are included. The height from the ground and time intervals between harvests are not standardised and these parameters could affect the yield.

Alternatively, harvesting is done by uprooting the whole plant at an earlier stage and bunching together for sale after washing the roots. The quality of the vegetable is affected by flowering. Plants that are flowering are not harvested but are left to seed.

Amaranth has shown that it benefits from intercropping with species such as Celosia and/or Corchorus.

Pests and diseases can be important problems with amaranth production.

At the National Horticultural Research Institute in Nigeria, many amaranth lines have failed due to wet rot of leaves and young stalks caused by Choenephora cucurbitarium. A principal insect pest is the lygus bug or Lygus lineolarius, which can extensively damage the flowering head. Under Australian conditions, the Lixus weevil (Lixus masterii) can cause severe damage to the stems of plants.

Amaranth can also suffer injury from the Fall Armyworm, Spodoptera frugiperda and the curly top virus disease, which is transmitted by the beet leafhopper, Circulifer temellus.

If the leaves are harvested, it is traditional in west Africa to soak the plant in water before transporting it to the market as this gives the leaves a fresh look. The leaves are arranged in bunches that are usually spread on a raffia tray in the market stalls or else hawked in the street. Since evaporation takes place rapidly, more water is sprinkled on the leaves at regular intervals.

Amaranth is one of the very few double-duty plants. The grain contains a high level of protein, perhaps averaging 15%, with an amino acid balance that means it can supplement the amino acids found in a diet that is high in cereals (which are deficient in lysine) and legumes (which are deficient in the sulphur amino acids). The leaves can be used as a tasty leafy vegetable, often preferred to spinach by some people.

Amaranth leaf protein contains more lysine than the best high-lysine corn and more methionine than soybean meal. Vegetable amaranth can also be used in feed lots for cattle or other intensively reared animals.

Amaranthus species demonstrate high levels of variability in leaf size, leaf shape, bolting pattern, growth and regrowth ability, number of economic branches, and colour.

Amaranth offers more genetic diversity in its present undeveloped state than do many widely grown crops. The wide geographical spread of the genus has resulted in the evolution of many land races in widely separated areas. The huge gene pool will be very important to the future development of the crop.

The success of the South African amaranth industry must be based on the areas where the crop is in high demand. Such areas would be rural areas where the crop is known well by the consumers and this can only be done properly if a marketing chain is developed at each level.

Becker, R, EL Wheeler, K Lorenz, AE Stafford, OK Grosjears, AA Betschart and RM Sanders (1981) A composition study of amaranth grain. Journal of Food Science 46: 1175-1180

Brenner, D and Haupti, H (1990) Seed shattering control with indehiscent utricles in grain amaranth seed oil. Legacy 3: 2-3 American Amaranth Institute, Bricelyn, Minnesota, USA

Bharat, PS and FW Wayne (1991) Population density and soil pH effects on vegetable amaranth production In J Janick and JE Simon (ed) 'New crops' John Wiley and Sons, Inc, pp562-4.

Feine, LB, RR Harwood, CS Kauffin and JP Senft (1979) Amaranth, gentle giant of the past and future 41-63 In GA Ritchie (ed) 'New agricultural crops' Westview Press, Boulder, Colorado, pp 41-63.

Grubben, GJH (1976) Cultivation of amaranth as a tropical leaf vegetable Amsterdam, Department of Agriculture, Royal Tropical Institutes, 67

Ikeorgu, JEG (1990) Glasshouse performance of three leafy vegetables grown in mixtures in Nigeria. Scientia Horticulturae 43: 181-8

Makus, DJ (1989) Aluminium accumulation in vegetable amaranth grain in a soil with adjusted pH value. Hortscience 24:460-3

National Academy of Sciences (1985) Amaranth: Modern prospects for an ancient crop. National Academy of Sciences, Washington DC

Opeke, LK (1963) Final report of the vegetable breeding programme of the Research Division of the Moore Plantation, Ibadan, Nigeria

Whiting, MM (1994) Genetic variability in grain amaranth, including response to attack by the Lixus weevil (Lixus mastersi). Final Year Study project, The University of Queensland Gatton College.

New crops survey (leading to the Second Edition of the Directory of New Crops Workers in Australia)

A survey was conducted earlier this year by the New Crops group from the University of Queensland. The survey was distributed to the readers of the Australian New Crops Newsletter and its purpose was to identify the interests of those receiving the Newsletter. An outcome of the information generated was to be the creation of a Directory of New Crops Workers for Australia, the principal task of this study project. A total of 242 surveys was returned and the details supplied by members of the Australian New Crops industry have been entered into the directory. The survey has found a wide variety of interests among the Australian New Crops workers.

Atherton oak (Athertonia diversifolia L.); the queen of nuts.

Field studies in high-amylose maize

Osmoregulation as a useful tool in plant breeding
(Exchange Masters student, University of the North, South Africa)

A review of the performance of Ingard cotton during 1996-7.

Establishment of F₁ hybrids and F₂ populations from crosses between lines of Setaria italica.

Typical plants of four accessions of Setaria italica L. (Foxtail millet) were grown to the flowering stage in the glasshouse at the University of Queensland Gatton College during early December, 1996. Anthesis occurred in the early morning (between 4.00 and 8.00 a.m.). Plants of accessions 108519 and 108046 were emasculated prior to anthesis and cross-pollinated using pollen from plants of accessions 108463 and 108541, respectively. Cross 1 (108519x108463) was relatively easy to carry out, since the female parent had relatively large florets (for millet) and the male parent released pollen over several mornings. Cross 2 (108046x108541), on the other hand, was more difficult to emasculate and pollinate because florets were much smaller.

F₁ plants were grown in the glasshouse (between February and March, 1997) alongside the respective parents and several morphological characteristics recorded for F₁ hybrid plants and parents. The authenticity of each F₁ plant was tested by comparison with the respective parents. As a result, postulated hybrids and selfed (female) plants were identified.

The distribution of characters between the parents was critical for distinguishing true F₁ hybrids from selfed (female) plants. Ideally, simply inherited dominant characters should be located in the male parent. Characters of low heritability, because of more complex genetic control, or because of strong environmental influences, were less useful for identifying genuine F₁ hybrid plants.

An F₂ population from an authenticated F₁ plant from Cross 1 was grown in the growth cabinet during May and June, 1997. This F₂ population segregated for a range of characters:

• anther colour, tiller number at maturity and stem colour were postulated as being under the control of a single gene; and
• bristle length, tiller number at one month, days to anthesis, flag leaf length, head width and peduncle width were postulated as being under the control of two genes.

Male dominant markers such as orange anthers and long bristles have provided a rapid test for the authenticity of F₁ hybrids in S. italica. Stem colouration appeared to be under the control of a single dominant gene of maternal parent origin in these crosses. This character, if present in a male parent, could be useful in recovering hybrids, since stem colouration was expressed in seedlings.

A comparison between folk-lore and pharmaceutical practice for six medicinal herb species.

A herb is a useful plant (French, 1994). It is not strictly a herbaceous plant (a plant that dies down before becoming woody), it is a label attached to a plant because of its usefulness. The range of uses can be very broad, including medicinal, culinary and cosmetic uses, as well as pest control.

Herbs were important to civilisations before they had a strong base of scientific knowledge, and were used for protecting against evil, communicating with the gods or acquiring wisdom (Fletcher, 1988).

The worldwide trade in herbs, spices and medicinal plants is increasing and was valued at over US$1 billion in 1988. This increase has occurred because western society has been returning to herbs for seasoning, flavouring and perfume and has been investigating their usefulness as sources of alternative medicines. Herbs are also being used as a source of active therapeutic substances for use in conventional medicine (Fletcher, 1988).

There is consumer pressure on modern agriculture and horticulture to move away from the use of agrochemicals, coupled with an increased community awareness of the importance of environmental protection and healthier living. This has impacted on the herb industry and has resulted in practices such as organic growing and integrated pest management (IPM) becoming mainstream in the industry.

The increased level of public acceptance of naturopaths, homeopathy, acupuncture, aromatheraphy and herbalists is a further result. This has resulted from social changes in the last few decades: changes such as the weakening of the Christian church’s influence over the general public, allowing people to explore other philosophies and to think for themselves. Disillusionment with the western system of medicine, and its practice of "removing the symptom, not the cause", has led people to look for help elsewhere.

The majority of people in Australia would be familiar with garlic, and the notion that garlic is helpful if a person is feeling sick. Another herb that has become commonplace is Echinacea, which has gained a reputation as being useful for boosting the immune system. Aloe vera has a reputation for helping to heal sunburn. It is seen as ‘healthy’, so its inclusion in cosmetics has been used as a marketing ploy. Products such as soaps, sunburn cream, moisturising lotions and make-up containing aloe vera are currently readily available.

This is the commercialisation of herbalism, making the herb recognisable, then using it to sell product. This is not making herbalism more recognised, but is showing up a flaw in modern consumer culture. If anything is labelled in an aesthetically pleasing way, is promoted as being ‘good’ for the consumer and is presented in this manner on television, then the modern consumer has no fear, believing the product must be acceptable or even very desirable. These consumers would scoff if told that they were embracing herbalism.

The following questions need to be asked:

• Is there a place for herbalism in present day society?.
• Does herbalism deserve a place alongside medicine?
• Is herbalism comprised entirely of hype and old wives’ tales?

Answering these questions is the objective of this study. The questions will be approached by using five examples of medicinal herbs and examining their links with:

• traditional folklore and magic,
• their importance to herbalism and
• any scientific findings which may be relevant to any pharmacological action.

The medicinal herbs investigated were Comfrey (Symphytum officinale), Feverfew (Tanacetum parthenium), Ginseng (Panax ginseng, P. quinquefolius), Gotu Kola (Centella asiatica) and Lemon Balm (Melissa officinalis).

Identification and description of Pitaya, Hylocereus undatus (Haw.) Br. et R., a potential new crop for commercialisation in Australia
(Exchange final year student from Wageningen Agricultural University, The Netherlands).

The novel uses of millet in human foods (Dr Fletcher's role was as an adviser, not a supervisor).

A review of the potential of Queensland native species as new floriculture crops.

The world cutflower market was valued at AUD4.3 billion in 1992 and is currently estimated to be expanding at a rate of 4-6% per annum (Batt, 1994).

The Australian native cutflower industry is one of the fastest growing rural industries to emerge in the last decade, with the major contribution to the industry coming from the export of Australian wildflowers. The total value of wildflower exports increased from approximately AUD2.7 million in 1980/81 to AUD28 million in 1995/96.

The cultivation of Australian native plants for commercial cutflower production first occurred in the early 1900's (Lamont, 1983a) but it was not until the late 1970's that the industry began to be developed to any extent.

Seasonal harvesting from the wild in Western Australia, and to some extent in Queensland and New South Wales, formed the initial base of the industry. Over time, however, managed natural stands and cultivation in the form of plantations and shade/green-house production have been developed. Since the mid 1980's, the gross value of production from cultivation has exceeded that from bush harvesting. The Rural Industries Research and Development Corporation (RIRDC, 1994) has estimated that 71% of the total wholesale value of Australian wildflowers exported in the 1992-1993 fiscal year was derived from cultivated stands.

The Australian wildflower industry is highly decentralised. As a result, accurate data regarding the value of the industry are difficult to obtain. Data from the Australian Bureau of Statistics (ABS) indicate that the wholesale value of all Australian flower exports was AUD30.181 million in 1995/96; from this total, the Australian wildflowers and foliage exports contributed approximately 93% (AUD28 million, FECA, 1996).

Estimates of the size of the Australian domestic floriculture market suggest that in 1994, the farm-gate value of Australian wildflowers supplied to the domestic market was between AUD10 and 13 million (RIRDC, 1994).

Growth in the domestic market has been relatively minor in comparison with exports; most growth on the domestic market has been in the supermarket sector. Sales of wildflowers in supermarkets have grown from nothing in 1989, to 5% of the total domestic wildflowers sales in 1994 (RIRDC, 1994).

Australian has a largely under-exploited array of unique flora, a diversity of climatic regions and ready availability of land and water. Hence, this country should be ideally positioned to acquire a greater share of the expanding world flower market.

Currently however, Australia's share of the world market is diminishing due to the more rapidly expanding floriculture industries in other countries. The greatest rate of expansion is currently being shown by Colombia, Israel, Kenya, Zimbabwe and the Netherlands (Batt, 1994). All of these countries, with the exception of the Netherlands, produce Australian natives and to some extent compete directly with Australian wildflower exports.

Australia's unique germplasm resource is regarded as one of the major strengths of the Australian wildflower industry with the domestication of wild species considered to be one of the key factors to further industry expansion. Development of Australian germplasm is occurring domestically, but is occurring at a faster pace overseas. Israel is currently regarded as the party most interested in our under-developed Australian species.

The loss of control of under-developed germplasm to overseas plant breeders is a concern to the Australian industry and the general industry view is that greater Government support should be given to the development of Australian germplasm in Australia (RIRDC, 1994).

Currently there are approximately 300 species of Australian flora utilised for commercial cutflower/foliage production; most of these species are bush harvested from Western Australia (Carson, 1995). A relatively small percentage of species make up the bulk of production, with other species being bush harvested in very low volumes.

The aim of this case study was to provide an overview of the Queensland wildflower industry and to evaluate whether the development of indigenous Queensland species for commercial cultivation is warranted.

The four types of production system used in this state have been reviewed and the potential for each production system to bring about industry growth on a sustainable basis has been assessed.

The development of a protocol for germination and establishment of Echinacea angustifolia CD.

This study has been conducted with the aim of developing a protocol for commercial propagation of Echinacea angustifolia DC.

The first experiment, in autumn 1996, at facilities located at the Horticultural Field Section Laboratory, University of Queensland Gatton College and at Plantalab Laboratories Pty Ltd, Hodgonsvale, Queensland sought to develop a suitable technique for increasing the rate and uniformity of germination of E. angustifolia achenes.

The second experiment compared three rates of fertiliser, for their effects on the seedlings transplanted from the first experiment.

The third experiment, in spring 1996, investigated five forms of propagation medium, for their effects on transplanted seedlings germinated according to the most suitable procedure derived from the first experiment.

It has been concluded that stratification of E. angustifolia achenes at 5° C for one week in the dark, using a priming solution of 1.0mM ethephon (2-chloroethylphosponic acid) increases the rate and uniformity of germination. It has also been concluded that seedlings be established in a propagation media with a high air-filled porosity, fertilised with 1kg of Mini-Osmocote® with an N:P:K ratio of 18:6:12 per cubic metre.

The potential of Foxtail Palm (Wodyetia bifurcata) as a new crop.

Conclusions

The foxtail palm has the capacity to be one of the most popular palms in the landscaping industry. Its hardiness and aesthetic appeal will make it the first choice in many backyard gardens. As the reputation of this palm's survivability grows so will its popularity. The domestic use of palm is widespread, but supply at this time is limited.

Supply is limited because of the requirement for a commercial wildlife harvest licence for nurseries and propagators to be able to sell the plant.

The enforcement of the requirement of a commercial wildlife harvest licence, by the Department of Environment and Heritage has been concerning nursery growers. This is because of harsh fines imposed, caused several nurseries to go out of business.

Evaluation of vetiver grass as a new crop.

Vetiver grass (Vetiveria zizanioides) is widely distributed, being grown in 86 countries throughout the world. The plant is capable of handling a wide range of climates, soils, droughts, fires, mechanical and grazing damage. It has a non-invasive habit and in a cropping system, the low competitive nature of vetiver grass means that there is little chance of it becoming a weed, since it remains where it has been planted. The plant doesn’t act as a host for crop diseases.

As a soil conservation tool, it has many desirable features for erosion control and it can also provide a windbreak for some other crop, such as seedling cotton on the Darling Downs.

The true advantage of vetiver grass is its function as a living barrier that controls water runoff and conserves water for crops. Vetiver is easy to establish as a hedge, requires little maintenance and is cheaper than convention erosion control methods. It is also more efficient in controlling sheet erosion than conventional methods. It is cheap and easy to propagate and will last for decades, once established.

Vetiver grass, however, requires more scientific research to ensure that it won’t become an environmental weed. The plant is poorly understood, especially its morphology, physiology and ecology. Although most experience with vetiver grass has only been empirical observation, with this occurring in so many countries, its effectiveness in controlling erosion needs to be evaluated in this country.

Investigation of the oil gland frequencies on the surface of tea tree leaves (Melaleuca alternifolia).

A survey of the factors determining the distribution of Neem (Azadirachta indica) in Australia.

A study of the growth characteristics of Marama bean (Tylosema esculenta).

Analysis of grain legume crops to be grown in rotation with irrigated cotton in northern New South Wales.

Studies of aneuploidy in triticale

(Finalist for the Bryen Medal)

Formulation of a sampling procedure for use in flower and fruiting studies in cashew (Anacardium occidentale L.).

Studies of earliness and tillering ability in wheat to find multi-tillering.

Genetic variability in the grain amaranth (Amaranthus spp) including response to attack by the Lixus weevil.

(Winner of the Bryen Medal for 1993).

Studies of coleoptile length and its relationship to plant establishment and gibberellic effects in wheat.
(Co-winner of Westpac award)

Studies in the use of Hordeum bulbosum for haploids.

The relationship between grain weight and coleoptile length in wheat.
(Finalist for the Bryen Medal).

Contact: Dr Rob Fletcher, School of Agriculture and Horticulture, The University of Queensland Gatton, 4343; Telephone: 07 5460 1311 or 07 5460 1301; Facsimile: 07 5460 1112; International facsimile: 61 7 5460 1112; Email: r.fletcher@mailbox.uq.edu.au

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Latest update 30 October 2000 by: RF