Issue No 10, July 1998.

NOTICE: Hard copies of the Australian New Crops Newsletter are available from the publisher, Dr Rob Fletcher. Details of availability are included in the Advice on Publications Available.

26. Research in new crops

FL Stoddard, DR Marshall, MMH Ali, S Fiffer, SUAK Gunasekera, IHMHB Herath, S Sherieff

Plant Breeding Institute and
Department of Crop Sciences
The University of Sydney

The population genetics of rust (Uromyces viciae-fabae), Ascochyta blight (Ascochyta fabae) and chocolate spot disease (Botrytis fabae) are under investigation. Isozyme analyses have shown no variation within, and little between, populations of the rust fungus. There is considerable variation between populations of the Ascochyta fungus.

Certain isozyme markers have also provided clear discrimination between Ascochyta species.

Detached leaf tests have been developed for studying the resistance of faba beans to rust. In a diallel of five varieties of varying levels of rust resistance, we found that resistance was dominant to susceptibility. The reciprocal crosses showed that there are important cytoplasmic contributions to resistance as well, with the most resistant cytoplasm being in the genetically most susceptible population. A rapid in-vitro assay has also been developed for screening faba beans for resistance to chocolate spot disease.

We have attempted to develop male sterility systems in faba bean that would be more robust than the available cytoplasmic systems. A nuclear-genetic form of male sterility was isolated following mutagenesis and characterised with a number of molecular markers.

We are investigating carbohydrate quality in faba beans. Variation in amylose content of starch and in oligosaccharide content ae under examination and, if necessary, will be expanded through mutagenesis.

The genetic basis of extremes in carbohydrate quality will be investigated.

Abstract of a PhD awarded by the University of Tasmania to Dr Shaun Lisson
Currently Crop and Soil Modeller
CSIRO, Davies Laboratory
University Drive, Douglas
Townsville Qld 4814
Telephone: 07 4753 8567
Shaun.Lisson@tag.csiro.au

The primary objective of the study was to show whether fibre of value as a reinforcing agent in newsprint production could be produced economically from hemp and flax grown in Tasmania. This involved an integrated analysis of the whole potential industry, with studies in crop production, pulp and paper manufacture and economic viability.

Another objective of the study was to develop a computer model for simulating the growth, development and yield of hemp in response to climatic, soil and management inputs. This would enable the results of this project to be extrapolated to other suitable production areas.

Of the nine hemp cultivars that were assessed, Kompolti and Futura 77 were the best performing, producing crops in excess of 2 m high and yielding up to 1500 g/m2 of oven dry stem. The results from sowing date trials suggest that September is the optimum month for sowing hemp in Tasmania. Later sowings resulted in a reduction in stem yield associated with a shortening of the thermal time duration from sowing to flowering. Sowings prior to September appear to be limited by premature flowering in response to short daylengths.

In an irrigation trial conducted in north west Tasmania, significant stem yield differences were not apparent for irrigation regimes based on refill to field capacity at deficits down to 120 mm. Maximum bark yield was obtained from regimes based on a 60 mm deficit or less (water consumption of 535 mm). The stem yields under rainfed conditions were substantially below those of the irrigated treatments. Stem yield responded in a parabolic manner to plant densities ranging from 50 to 300 plants/m2, with maximum yields at about 110 plants/m2.

The results from a flax cultivar trial showed that stem yields of selected European cultivars were superior to a number of older Australian cultivars, developed for the Australian flax industry during the mid 1900's. The cultivar Ariane was selected for further field trials and produced crops with oven dry stem yields of up to 1000 g/m2.

Field studies with a range of sowing date and irrigation treatments demonstrated that flax could be sown from autumn through to spring, under either rainfed or irrigated conditions. Maximum stem and seed yields were from an autumn sowing with supplementary irrigation from flowering to late grain fill.

The optimum seeding rate for autumn sown flax was found to involve a compromise between maximising yield and minimising the potential losses from lodging apparent at densities in excess of about 1000 plants/m2. Lodging was not a major problem at the optimum seeding rates for spring sowings of flax.

Controlled environment studies were conducted into the response of pre-emergent development to temperature and the flowering response of selected hemp cultivars to photo-period. Parameters, constants and functions derived from these studies, the field trials and from selected references, were then used to develop a hemp simulation model. The model adequately predicted phenology, leaf area and biomass production for cv. Kompolti grown in north west Tasmania.

The Australian newsprint industry currently uses a mixture of locally sourced eucalypt, radiata pine and recycled paper pulps, blended with an imported kraft (chemical) pulp. The purpose of the kraft pulp is to reinforce the newsprint.

The primary aim of the pulping trials conducted in this study was to investigate the potential of using flax and hemp bark and whole stem pulps as alternative reinforcing agents in newsprint production. The existing cold caustic soda (CCS) and thermo-mechanical (TMP) processes were trialled with a view to harnessing the existing infrastructure and expertise.

Cold caustic soda pulp made from the bark fraction formed paper of very high tear index, but with lower tensile index and tensile energy absorption than would be desirable from softwood kraft. This limitation might be overcome by using a higher proportion of non-wood pulp in the overall newsprint blend or through breeding improvements. The use of pulping (and pre-pulping) equipment more suited to non-woods may overcome handling difficulties associated with excessive fibre length.

Pulps were also made from the core fraction to assess its suitability as a supplement to the short-fibred component of the existing newsprint blend. Whilst potentially suited for use as a short-fibred supplement in newsprint manufacture, the properties of the core pulps are not currently in demand within the industry.

Interest from the newsprint industry in taking the financial risk of adopting hemp and flax based pulps as an alternative to kraft, would require that the total cost be somewhat less than the imported option. Similarly, interest from primary producers requires that the gross returns from these crops are at least comparable with a range of crop alternatives. The minimum bark price (mill gate) that is likely to attract farmers, would vary between flax and hemp and with growing conditions.

Dual purpose flax grown under dryland conditions would require a separated bark price in the vicinity of $400/t to $450/t. Irrigated hemp and flax crops grown in the more productive north west area of the state would require a price in excess of about $650/t. These minimum bark prices are not attractive to the newsprint industry at present.

Future financial viability will depend on a number of factors, including: fibre yield and quality (eg bark proportion in the stem and fibre tensile strength properties) improvements, elevated kraft pulp prices and the establishment of strong markets for the stem core fraction and the seed of flax.

Jason Young
Final year study project report.
BAppSc (Horticultural Technology)
School of Land and Food
Faculty of Natural Resources, Agriculture and Veterinary Science
The University of Queensland
Gatton College Qld 4345
May, 1998

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.

Jacinta Norton
Final year study project report.
BAppSc (Horticultural Technology)
School of Land and Food
Faculty of Natural Resources, Agriculture and Veterinary Science
The University of Queensland
Gatton College Qld 4345
May, 1998

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.

Contact: Dr Rob Fletcher, School of Land and Food, The University of Queensland Gatton College, 4345; 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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originally created by: GK; latest update 6 June 1999 by: RF