Implementation of an electronic nose for continuous odour monitoring in a poultry shed

Continuous odour monitoring technologies are necessary to understand the complex odour-generating mechanisms within poultry housing as well as to identify strategies to reduce the impact of odour emissions on local communities. To evaluate electronic nose (EN) technologies for continuously assessing odour concentration in poultry housing, a mobile laboratory containing an electronic nose and an associated sample delivery system was deployed to a commercial poultry farm and tested over a broiler production cycle. The results demonstrated that it was possible to develop a model to allow an electronic nose to provide a semi-continuous measurement of odour concentrations. The electronic nose was also able to demonstrate the influence of shed conditions on odour emissions.

Native cut foliage production using Proteaceae species - A research summary

The Queensland Department of Primary Industries and Fisheries in collaboration with the Rural Industries Research and Development Corporation and Yuruga Nursery Pty Ltd have been conducting research into the development of five native foliage products. The three species and two cultivars being developed for commercial production are: Grevillea baileyana, Lomatia fraxinifolia, Athertonia diversifolia, Stenocarpus 'Forest Lace' and Stenocarpus 'Forest Gem'. Previous research involved an evaluation of 21 species from which these five were selected based on market comments, post harvest life and ability to grow under a range of climatic conditions. Lomatia fraxinifolia, Grevillea baileyana and Athertonia diversifolia are all native to north Queensland rainforests. Stenocarpus 'Forest Gem' and Stenocarpus 'Forest Lace' are hybrids and have been selected by Yuruga Nursery Pty Ltd. Both Stenocarpus cultivars are protected by Plant Breeders Rights. Current research into the commercial development of these species involves: market research, post harvest trials, field trials and grower training. Two field trials have been established on the Atherton Tablelands, one in the high rainfall zone at Yungaburra and the other in the low rainfall zone west of Mareeba. Field trials will evaluate the effects of fertiliser rates and pruning techniques on yield. Pests and diseases will be identified and appropriate control measures tested on trial plants. Vase life evaluations have also been carried out and the results indicate that the five foliages have exceptional vase life. All five products are being sold on the Australian domestic market in small volumes at this stage; it is anticipated that sales will significantly increase in the coming years. A number of leading exporters have indicated that the foliages may also meet the requirements of export markets. Stenocarpus 'Forest Gem' is similar in appearance to Persoonia longifolia (Barker Bush), which is a bush-picked foliage currently exported from Australia to a number of overseas markets.

Building better information products by assessing the information needs of growers of subtropical strawberries in Queensland

Timely access to effective technical information is a key ingredient of profitable strawberry production. Through the Better Berries Program, a joint RD&E initiative of government and industry, a number of information products and services have been provided in recent years to Australia's subtropical strawberry industry, centred in southern Queensland. However, there is a lack of knowledge of how well these are meeting the information needs of growers, both in content and delivery. To better understand grower information use and needs, a stratified sample of 25 growers was interviewed on-farm during the 2004 season. Growers were asked about how they currently accessed information, what they thought of a range of information products and ideas on show, and what advice they would provide for information development in the future. Results indicated that information sought by growers and the style in which it is best presented, varied considerably with grower experience, but little with farm size. New growers had a wide range of needs while the needs of experienced growers were focused mainly on problem identification and new production development. Interestingly, the overwhelming majority across all sectors still preferred paper-based information products despite their extensive use of computers for business purposes. The findings were used to develop a strategy for an improved range of technical information products and services that are more accessible, easier to use, more timely, and more relevant to the needs of growers.

Managing the risk of glyphosate resistance in Australian glyphosate-resistant cotton production systems

BACKGROUND: Glyphosate-resistant cotton varieties are an important tool for weed control in Australian cotton production systems. To increase the sustainability of this technology and to minimise the likelihood of resistance evolving through its use, weed scientists, together with herbicide regulators, industry representatives and the technology owners, have developed a framework that guides the use of the technology. Central to this framework is a crop management plan (CMP) and grower accreditation course. A simulation model that takes into account the characteristics of the weed species, initial gene frequencies and any associated fitness penalties was developed to ensure that the CMP was sufficiently robust to minimise resistance risks. RESULTS: The simulations showed that, when a combination of weed control options was employed in addition to glyphosate, resistance did not evolve over the 30 year period of the simulation. CONCLUSION: These simulations underline the importance of maintaining an integrated system for weed management to prevent the evolution of glyphosate resistance, prolonging the use of glyphosate-resistant cotton.

Analysis of high yielding maize production - A study based on a commercial crop

This paper reports on the use of APSIM - Maize for retrospective analysis of performance of a high input, high yielding maize crop and analysis of predicted performance of maize grown with high inputs over the long-term (>100 years) for specified scenarios of environmental conditions (temperature and radiation) and agronomic inputs (sowing date, plant population, nitrogen fertiliser and irrigation) at Boort, Victoria, Australia. It uses a high yielding (17 400 kg/ha dry grain, 20 500 kg/ha at 15% water) commercial crop grown in 2004-05 as the basis of the study. Yield for the agronomic and environmental conditions of 2004-05 was predicted accurately, giving confidence that the model could be used for the detailed analyses undertaken. The analysis showed that the yield achieved was close to that possible with the conditions and agronomic inputs of 2004-05. Sowing dates during 21 September to 26 October had little effect on predicted yield, except when combined with reduced temperature. Single year and long-term analyses concluded that a higher plant population (11 plants/m2) is needed to optimise yield, but that slightly lower N and irrigation inputs are appropriate for the plant population used commercially (8.4 plants/m2). Also, compared with changes in agronomic inputs increases in temperature and/or radiation had relatively minor effects, except that reduced temperature reduces predicted yield substantially. This study provides an approach for the use of models for both retrospective analysis of crop performance and assessment of long-term variability of crop yield under a wide range of agronomic and environmental conditions.

Host-plant resistance and biopesticides: Ingredients for successful integrated pest management (IPM) in Australian sorghum production

There are two major pests of sorghum in Australia, the sorghum midge, Stenodiplosis sorghicola (Coquillett), and the corn earworm, Helicoverpa armigera (Hübner). During the past 10 years the management of these pests has undergone a revolution, due principally to the development of sorghum hybrids with resistance to sorghum midge. Also contributing has been the adoption of a nucleopolyhedrovirus for the management of corn earworm. The practical application of these developments has led to a massive reduction in the use of synthetic insecticides for the management of major pests of sorghum in Australia. These changes have produced immediate economic, environmental and social benefits. Other flow-on benefits include providing flexibility in planting times, the maintenance of beneficial arthropods and utilisation of sorghum as a beneficial arthropod nursery, a reduction in midge populations and a reduction in insecticide resistance development in corn earworm. Future developments in sorghum pest management are discussed.

Alkaloid production by isolates of the sorghum ergot pathogen (Claviceps africana) from Australia and other countries

Isolates of Claviceps africana from Australia, Africa, Asia, and America were tested for the production of dihydroergosine (DHES), and its biogenic precursors dihydroelymoclavine (DHEL) and festuclavine (FEST), in culture. Several growth media were evaluated to optimise alkaloid production with little success. The best of these involved 2-stage culturing on high-sucrose substrate. Australian C. africana isolates varied widely and inconsistently in alkaloid production, with DHES concentrations in mycelium ranging from: <0.1 to 9 mg DHES/kg; <0.1 to 1.6 mg DHEL/kg; and <0.1 to 0.4 mg FEST/kg. In a separate experiment using similar culturing techniques, DHES was produced by 2 of 3 Australian isolates, 1 of 3 USA isolates, 1 of 4 Indian isolates, the sole Puerto Rican isolate, the sole Japanese isolate, but not the sole South African isolate. In this experiment, DHES concentrations detected in mycelium of Australian isolates (0.1-1.0 mg DHES/kg) were of similar magnitude to isolates from other countries (0.2-1.8 mg DHES/kg). Three C. africana isolates, including one that produced only traces of alkaloid in culture after 8 weeks, were inoculated onto panicles of sterile male sorghum plants. After 8 weeks, all 3 isolates produced 10-19 mg DHES/kg in the panicles, demonstrating that the growing plant favoured more consistent alkaloid production than culture medium.

Impact of subsoil constraints on wheat yield and gross margin on fine-textured soils of the southern Victorian Mallee

The APSIM-Wheat module was used to investigate our present capacity to simulate wheat yields in a semi-arid region of eastern Australia (the Victorian Mallee), where hostile subsoils associated with salinity, sodicity, and boron toxicity are known to limit grain yield. In this study we tested whether the effects of subsoil constraints on wheat growth and production could be modelled with APSIM-Wheat by assuming that either: (a) root exploration within a particular soil layer was reduced by the presence of toxic concentrations of salts, or (b) soil water uptake from a particular soil layer was reduced by high concentration of salts through osmotic effects. After evaluating the improved predictive capacity of the model we applied it to study the interactions between subsoil constraints and seasonal conditions, and to estimate the economic effect that subsoil constraints have on wheat farming in the Victorian Mallee under different climatic scenarios. Although the soils had high levels of salinity, sodicity, and boron, the observed variability in root abundance at different soil layers was mainly related to soil salinity. We concluded that: (i) whether the effect of subsoil limitations on growth and yield of wheat in the Victorian Mallee is driven by toxic, osmotic, or both effects acting simultaneously still requires further research, (ii) at present, the performance of APSIM-Wheat in the region can be improved either by assuming increased values of lower limit for soil water extraction, or by modifying the pattern of root exploration in the soil pro. le, both as a function of soil salinity. The effect of subsoil constraints on wheat yield and gross margin can be expected to be higher during drier than wetter seasons. In this region the interaction between climate and soil properties makes rainfall information alone, of little use for risk management and farm planning when not integrated with cropping systems models.

Sustaining productivity of a Vertosol at Warra, Queensland, with fertilisers, no-tillage or legumes. 9. Production and nitrogen benefits from mixed grass and legume pastures in rotation with wheat

Reduced supplies of nitrogen (N) in many soils of southern Queensland that were cropped exhaustively with cereals over many decades have been the focus of much research to avoid declines in profitability and sustainability of farming systems. A 45-month period of mixed grass (purple pigeon grass, Setaria incrassata Stapf; Rhodes grass, Chloris gayana Kunth.) and legume (lucerne, Medicago sativa L.; annual medics, M. scutellata L. Mill. and M. truncatula Gaertn.) pasture was one of several options that were compared at a fertility-depleted Vertosol at Warra, southern Queensland, to improve grain yields or increase grain protein concentration of subsequent wheat crops. Objectives of the study were to measure the productivity of a mixed grass and legume pasture grown over 45 months (cut and removed over 36 months) and its effects on yield and protein concentrations of the following wheat crops. Pasture production (DM t/ha) and aboveground plant N yield (kg/ha) for grass, legume (including a small amount of weeds) and total components of pasture responded linearly to total rainfall over the duration of each of 3 pastures sown in 1986, 1987 and 1988. Averaged over the 3 pastures, each 100 mm of rainfall resulted in 0.52 t/ha of grass, 0.44 t/ha of legume and 0.97 t/ha of total pasture DM, there being little variation between the 3 pastures. Aboveground plant N yield of the 3 pastures ranged from 17.2 to 20.5 kg/ha per 100 mm rainfall. Aboveground legume N in response to total rainfall was similar (10.6 - 13.2 kg/ha. 100 mm rainfall) across the 3 pastures in spite of very different populations of legumes and grasses at establishment. Aboveground grass N yield was 5.2 - 7.0 kg/ha per 100mm rainfall. In most wheat crops following pasture, wheat yields were similar to that of unfertilised wheat except in 1990 and 1994, when grain yields were significantly higher but similar to that for continuous wheat fertilised with 75 kg N/ha. In contrast, grain protein concentrations of most wheat crops following pasture responded positively, being substantially higher than unfertilised wheat but similar to that of wheat fertilised with 75 kg N/ha. Grain protein averaged over all years of assay was increased by 25 - 40% compared with that of unfertilised wheat. Stored water supplies after pasture were < 134mm (< 55% of plant available water capacity); for most assay crops water storages were 67 - 110 mm, an equivalent wet soil depth of only 0.3 - 0.45 m. Thus, the crop assays of pasture benefits were limited by low water supply to wheat crops. Moreover, the severity of common root rot in wheat crop was not reduced by pasture - wheat rotation.

Effect of micro-propagation on the health status of strawberry planting material for commercial production of strawberry runners for Queensland

Plant tissue culture has been used for a number of years to produce micropropagated strawberry plants for planting into runner growing beds in the Stanthorpe (Queensland) and Bothwell (Tasmania) regions. This process has allowed the rapid release of new cultivars from the LAWS (Late Autumn, Winter, Spring) breeding program into the current runner production system. Micro-propagation in vitro allows plants to be produced during the autumn and winter months, when mother plants would normally be in a fruit production phase in the field in Queensland. The plants produced are of a high health status when they are planted. The subsequent arrival and build up of various diseases in the runner fields are closely monitored. Using tissue culture for the first generation reduces the time the plants spend in the field by twelve months, reducing disease incidence. To date, any disease outbreak has been successfully managed using early detection and rapid response methods.

Harmonising GAP programs for fresh produce in ASEAN region

Many forces are driving the global demand for assurance that fruit and vegetables are safe to eat and of the right quality, and are produced and handled in a manner that does not cause harm to the environment and the health, safety and welfare of workers. The impact of these driving forces is that retailer requirements for suppliers to comply with Good Agricultural Practice (GAP) is increasing and governments are strengthening legal requirements for food safety, environmental protection, and worker health, safety and welfare. The implementation of GAP programs currently within the ASEAN (Association of South East Asian Nations) region varies, with some countries having government certified systems and others beginning the journey with awareness programs for farmers. Under a project funded by the ASEAN Australia Development Cooperation Program, a standard for ASEAN GAP has been developed to harmonise GAP Programs in the region. The goal is to facilitate trade between ASEAN countries and to global markets, improve viability for farmers, and help sustain a safe food supply and the environment. ASEAN GAP is an umbrella standard that individual member countries will benchmark their national programs against to gain equivalence. The scope of ASEAN GAP covers the production, harvesting and postharvest handling of fresh fruit and vegetables on farm and postharvest handling in locations where produce is packed for sale. ASEAN GAP consists of four modules covering food safety, environmental management, worker health, safety and welfare, and produce quality. Each module can be used alone or in combination with other modules. This enables progressive implementation of ASEAN GAP, module by module based on individual country priorities.

Using a supply chain approach to guide R&D

Consumers today are presented with an increasing array of products. The growing competition for consumer expenditure requires a whole of supply chain approach to maintain market share for existing cultivars and to successfully commercialise new cultivars. The supply chain needs to deliver value and satisfaction to the end customer and profitability to their members. Critical to getting the product right is developing inherent robustness into the cultivar, and developing processes and systems through the whole supply chain that maintain product quality and add value. This paper describes the approach we have used in working with supply chains in Australia and Indonesia to identify priority areas for improvement. Our experience demonstrates the need for a champion in the supply chain with significant influence and a desire to improve. The paper also describes our approach towards improving a specific supply chain to achieve successful commercialisation of a new cultivar. The cultivar was primarily selected for good production characteristics and attractive visual appeal. The performance of the fruit is being monitored from farm to retail shelf to identify points where quality is lost and practices can be improved. A targeted R&D program is investigating ways of improving production efficiency (nutrition, flowering and canopy management), maturity standards to optimise flavour, harvesting and packing practices to reduce skin damage, and ripening and handling practices to optimise shelf life. This integrated approach is based on similar approaches used to improve the performance of existing mango and avocado cultivars.

Successful management of colletotrichum crown and stolon rot in runner production in sub-tropical Australia

Crown, stolon, and petiole rots caused by Colletotrichum gloeosporioides (C.g.) were first identified in runner beds of the Queensland Approved Runner Scheme (QARS) in February 1989. The outbreaks occurred annually from 1990 to 1994. Minor losses in subsequent fruit crops occurred from 1990 to 1993, with 50% post-establishment losses occurring on fruit farms in southeast Queensland in 1994. The objective of this work was to provide a control strategy for the disease that would give stability to the QARS. Runner-bed trials in 1993-1994 showed that Octave® (462 g/kg prochloraz as the MnCl2 complex) was highly effective in reducing the incidence field symptoms and laboratory recovery of C.g. from symptomless petioles. A simple detached petiole laboratory test for measuring fungicide efficacy in runner bed trials and for laboratory screening of fungicides, is described. Scheme protocols were changed to require that only foundation plants from tissue culture were allowed onto QARS sites. These were to be symptomless and to have tested negative for the presence of C.g. The application of Octave® at fortnightly intervals in all QARS nurseries has reduced the level of visible symptoms and the laboratory recovery of C.g. from symptomless petioles to almost zero.

Using APSIM-soiltemp to simulate soil temperature in the podding zone of peanut

Measurement or accurate simulation of soil temperature is important for improved understanding and management of peanuts (Arachis hypogaea L.), due to their geocarpic habit. A module of the Agricultural Production Systems Simulator Model (APSIM), APSIM-soiltemp, which uses input of ambient temperature, rainfall and solar radiation in conjunction with other APSIM modules, was evaluated for its ability to simulate surface 5 cm soil temperature in 35 peanut on-farm trials conducted between 2001 and 2005 in the Burnett region (25°36'S to 26°41'S, 151°39'E to 151°53'E). Soil temperature simulated by the APSIM-soiltemp module, from 30 days after sowing until maturity, closely matched the measured values (R2 ≥ 0.80)in the first three seasons (2001-04). However, a slightly poorer relationship (R2 = 0.55) between the observed and the simulated temperatures was observed in 2004-05, when the crop was severely water stressed. Nevertheless, over all the four seasons, which were characterised by a range of ambient temperature, leaf area index, radiation and soil water, each of which was found to have significant effects on soil temperature, a close 1:1 relationship (R2 = 0.85) between measured and simulated soil temperatures was observed. Therefore, the pod zone soil temperature simulated by the module can be generally relied on in place of measured input of soil temperature in APSIM applications, such as quantifying climatic risk of aflatoxin accumulation.

Screening selected myrtaceous tree species for production of essential oils in northern Queensland

Trials to identify alternative cropping options to Melaleuca alternifolia for northern Queensland essential oil growers were established at Dimbulah and Innot Hot Springs in 2001. Seed sources of Asteromyrtus symphyocarpa (1,8-cineole form), Eucalyptus staigeriana (citral), Melaleuca cajuputi subsp. cajuputi (trans-nerolidol), M. ericifolia (d-linalool), M. quinquenervia (trans-nerolidol and viridiflorol forms) and M. viridiflora (methyl cinnamate) with potential to produce commercial foliar oils were evaluated. Information was gathered on their adaptability, growth and oil yields over 49 months and 52 months (two harvests) from planting at Dimbulah and Innot Hot Springs, respectively. Of the species and chemotypes evaluated, M. quinquenervia showed potential for commercial production of trans-nerolidol, a compound used in perfumery. It had a very high survival rate (96%) and yields could be expected to improve dramatically from the average 100 kg/ha per harvest achieved in these trials with further research into selection of seed source, control of insect damage and breeding for genetic improvement. M. cajuputi subsp. cajuputi gave a similar performance to M. quinquenervia. The rarity of the trans-nerolidol form of this species and remoteness of its natural occurrence are impediments to further planting and research. E. staigeriana, with second harvest yields of ~600 kg/ha, performed exceptionally well on both sites but potential for development is limited by the ready availability of competitively priced E. staigeriana oil produced in South America. Survival of M. ericifolia ranged from 62% to 82% at 32 months (second harvest) at Innot Hot Springs and was deemed a failure at Dimbulah with poor growth and low survival, raising a major question about the suitability of this species for cultivation in the seasonally dry tropics. Planting of this species on a wider scale in northern Queensland cannot be recommended until more is known about factors affecting its survival. A. symphyocarpa and M. viridiflora were too slow-growing to warrant further consideration as potential oil-producing species at this time.