Research Publications and Outputs

Analysing the Benefits of Growing Crops after Rice in the Rice Growing Areas in Australia

Thu, 03 Nov 2005 00:00:00 GMT

Analysing the Benefits of Growing Crops after Rice in the Rice Growing Areas in Australia Faour, Khaled; Singh, Rajinder; Humphreys, E; Smith, David; Mullen, John The Murrumbidgee Irrigation Area (MIA), the Coleambally Irrigation Area (CIA), and the Murray Valley (MV) constitute the major Australian rice growing areas and are located in southern east Australia. According to the Ricegrowers' Association of Australia Inc. (2002), the annual value of production of rice was $357 million in 2001 and the industry generates more than $500 million from value-added exports annually, allowing these rice growing areas to play a significant role in the Australian economy. The rice growing areas are also among the areas where the sustainability of irrigated agriculture is under threat from rising watertables, soil salinity and other environmental consequences. The depth to watertables in more than 70 per cent of the MIA (MIA L&WMP, 1998), around 35 per cent of the CIA (CICL, 2001), and around 60 per cent of the MV (Murray Irrigation, 2001) is now around two metres from the soil surface. With the current land use practices, around 20 to 30 per cent of regions such as the MIA could become moderately salinised in the next 30 years due to rising watertables (Humphreys et al., 2001). Water leaching and run-off from rice-based farms form further problems. Paddocks are flood-irrigated during rice growing period between November to March. Although irrigation water is released prior to rice harvest, much of the water is retained by the soil even after rice harvest. The soil then slowly drains this water along with the added winter rainwater into the watertable beyond the root zone. This wet soil profile has the potential to become an extra economic resource for rice-based farms whenever it can be used to grow another crop during winter straight after rice. Growing winter crops immediately after rice harvest may reduce the amount of water drainage into watertables on rice-based farms. Successful adoption of this potentially attractive option seems to depend on good weather and rootzone water conditions, good drainage and timeliness in the rice harvesting, stubble burning, and winter crop sowing operations. Among the constraints for adding crops after rice are too much rain or waterlogging for the winter crop to survive, problems with stubble burn, pests, weeds, and unsuitable machinery leading to a high risk of crop failure (Humphreys and Bhuiyan, 2001). As one of the strategies to overcome the problems of rising watertables in rice growing areas, the Rice CRC is conducting Project 1205 “Quantifying and Maximising the Benefits of Crops after Rice”, henceforward referred to as Project 1205. Project 1205 aims at determining the constraints and the success factors for rice growers to produce winter crops and pastures after rice, and at measuring the impacts of this practice on environmental and economic sustainability. In particular, the project aims to measure the effects of growing wheat after rice on the productivity and water use efficiency of the rice-wheat cropping system. 2 The objectives of this economic analysis of project 1205 are: · To identify the common crop rotations in the main Australian rice-based farming systems, both with and without crops after rice; · To estimate the potential financial benefits of growing crops after rice; · To identify the economic benefits to the community from reduced accessions to groundwater; and · To compare returns with the costs to the CRC and its partners of developing and extending this technology. To measure the likely financial and economic benefits of growing crops after rice, the study relied heavily on the results from Humphreys et al. (2001).

Valuing a Test for Nitrogen Status in Rice

Thu, 03 Nov 2005 00:00:00 GMT

Valuing a Test for Nitrogen Status in Rice Singh, Rajinder; Williams, Robert; Mullen, John; Faour, Khaled Nitrogen is a crucial input for the efficient production of rice and is generally applied in two split treatments. The first treatment is given before flooding the rice paddocks at sowing time ie at the pre-flooding (PF) stage. The second treatment is applied within a week after the beginning of the panicle initiation (PI) stage. There is no pre-sowing test to estimate nitrogen requirements and farmers use cropping history to make this decision. Later in the season further nitrogen can be applied on the basis of existing Near Infra-red Reflectance (NIR) based nitrogen tissue test but yield potential has often been established by this time. A further source of yield risk is temperature prior to flowering and at high rates of nitrogen there is a potential for yield losses at low temperatures. The aim of one of the projects, funded by the Cooperative Research Centre (CRC) for Sustainable Rice Production, is to develop a nitrogen test for soils of rice paddocks. This would help determine the amount of nitrogen available in the soil and how much more nitrogen needs to be applied at the PF stage. The aim of this study is to first value the information that is provided to the rice growers at PF by the soil test on nitrogen availability and then measure returns to investment on research and extension to develop and promote this test. The problem is first presented in a decision tree framework. The Bayesian framework is then applied, where information provided by the test is used to revise perceived probabilities of yield outcomes under different nitrogen regimes. MaNage rice, a bio-economic model, is used to work out payoffs from different rates of nitrogen at PF on different nitrogen status soils. Finally, returns to investment on R&D are measured within a benefit-cost framework. The results reveal that the information provided by the soil test is valuable as the test helps farmers to use nitrogen more profitably. The outcome of the benefit-cost analysis shows that with the current accuracy levels the benefits from the new test are not sufficient to meet the costs involved on research. If the scientists were able to improve the accuracy of the test (ie at par with existing NIR tissue test), the returns to investment on the project would be quite significant.

Economic Analysis of Improving Cold Tolerance in Rice in Australia

Thu, 03 Nov 2005 00:00:00 GMT

Economic Analysis of Improving Cold Tolerance in Rice in Australia Singh, Rajinder; Brennan, John P; Farrell, Tim; Williams, Robert; Lewin, Laurie; Mullen, John The occurrence of low night temperatures during reproductive development is one of the factors most limiting rice yields in southern Australia. Yield losses due to cold temperature are the result of incomplete pollen formation and subsequent floret sterility. Researchers have found that in 75% of years, rice farmers suffer losses between 0.5 and 2.5 t/ha. Research is being undertaken to identify overseas rice varieties, that are cold tolerant under the local weather conditions and by using those genotypes as parent material, develop cold tolerance varieties of rice. A yield simulation model was used to measure reduction in losses due to cold at different minimum threshold temperatures, while the SAMBOY Rice model was used to measure the costs and returns of a breeding program for cold tolerance. The results of the economic analysis reveal that new cold tolerant varieties would lead to significant increase in financial benefits through reduction in losses due to cold, and an increase in yield from the better use on nitrogen by the cold tolerant varieties. The returns to investment on the research project are estimated to be high.

Study Of Water Use And Environmental Aspects Of Rice Growing

Thu, 03 Nov 2005 00:00:00 GMT

Study Of Water Use And Environmental Aspects Of Rice Growing Caldwell, Bruce The Council of Australian Governments (COAG) has agreed to a nationwide approach to water reform. The outcomes of the reform process are already having an impact on irrigation and ricegrowing and further impacts can be expected. Such changes should affect the direction of some of the future research to be undertaken by the Co-operative Research Centre for Sustainable Rice Production. The long-term sustainability of irrigation systems in arid zones has been shown, world wide, to have technical difficulties. As ricegrowing in arid zones is absolutely dependent on irrigation it is obvious the eventual sustainability of rice is inextricably linked to the sustainability of the irrigation systems as a whole. If irrigation systems start to fail for whatever reason (e.g. environmental degradation, water allocated to other purposes) then ricegrowing will decline. It is recognised that ricegrowing, as an irrigation activity, contributes to the environmental problems associated with irrigation. It is thus of fundamental importance to have a full understanding of this aspect of ricegrowing. It is also important that current rice farming practices and research efforts are adequately addressing such issues. This study examines the extent of ricegrowing as the predominant irrigation activity in the Murrumbidgee and Murray Valleys of New South Wales. Past and current policies of governments are reviewed in relation to access to water for irrigation and its use for ricegrowing. Data has been compiled on rice production, water availability, water use, ground watertables and salinity as these relate to the rice industry.

Rice Water Use Efficiency Workshop Proceedings

Thu, 03 Nov 2005 00:00:00 GMT

Rice Water Use Efficiency Workshop Proceedings Humphreys, E (ed) For rice grown under ponded conditions in the southern Murray Darling Basin, total evapotranspiration from the paddock during the ponded period can be estimated from Epdk = 0.9 x Epan = 1 x ETo, where ETo is calculated using a locally calibrated Penman equation (Meyer 2000). The long term average ETo at Griffith is 1160 mm (11.6 ML/ha) over the rice season (Oct…Feb), while rainfall averages 160 mm. Therefore rice requires 1000 mm, on average, to meet net evaporative demand. There is less certainty in weekly or monthly estimates of evapotranspiration from ETo or pan evaporation. The available data suggest that the crop factor increases during the season, reaching a maximum around anthesis, but the data are too variable and too few to assign monthly (or weekly) crop factors with confidence. Further refinement of monthly crop factors would assist in water budgeting during the irrigation season, especially in years of lower water availability. There is also little information on evapotranspiration from draining until harvest and after harvest, and its relationship with ETo or pan evaporation. Total ETo over the rice season (Oct…Feb) at Griffith, Finley and Tullakool is similar, but it is about 10% higher for Hay. The same is true for net evaporation (ETo-rain). Seasonal variations in ETo, rain and net evaporation are large. Therefore a rice paddock water use target based on seasonal conditions was adopted by the Rice Environmental Policy Advisory Group, commencing in the 1996/97 season. This target is calculated to be equal to ETo-rain+400, where all units are in millimetres. Rice paddock water use is routinely monitored by the irrigation companies, and the purpose of the target is to detect paddocks with excessive deep drainage (“leaky” paddocks) by identifying paddocks with high water use. The biggest gains to be made in improving rice water use efficiency are by identification of leaky paddocks and their amelioration or elimination from rice growing. Accurate identification of leaky paddocks requires knowledge of the period of ponding and the pre-rice soil water content – simple information which would be easy for farmers to provide. More accurate measurement of applied irrigation water is also needed, and substantial improvement could be made by increased on-farm recording of water deliveries – however, this would require additional effort from farmers which some (many?) may be reluctant to apply for a range of reasons including pressures on time and lack of desire for this type of information. Once the technology and systems are in place for more accurate identification of leaky paddocks, then the next gains in the drive towards higher rice water use efficiency would be firstly through implementation of the policy of restricting rice to areas that meet the water use targets, and secondly to progressively lower the rice water use target to ETo4 rain+ΔSWC+100, where ΔSWC is the increase in soil water content over the rice season in the rootzone (0-1 m). Socioeconomic factors are at present a major barrier to the adoption of all of these technically simple methods for improving rice water use efficiency. Furthermore, they consider the rice enterprise in isolation from other activities on the farm. Therefore alternative approaches examining whole farm water balances are being developed such as the SWAGMAN Farm model.

Remote Sensing Of Rice-Based Irrigated Agriculture: A Review

Thu, 03 Nov 2005 00:00:00 GMT

Remote Sensing Of Rice-Based Irrigated Agriculture: A Review Van Niel, Tom G; McVicar, Tim R The ‘Green Revolution’ in rice farming of the late 1960’s denotes the beginning of the extensive breeding programs that have led to the many improved rice varieties that are now planted on more than 60% of the world’s riceland (Khush, 1987). This revolution led to increases in yield potential of 2 to 3 times that of traditional varieties (Khush, 1987). Similar trends have also been seen in the Irrigation Areas and Districts of southern New South Wales (NSW) as the local breeding program has produced many improved varieties of rice adapted to local growing conditions since the 1960’s (Brennan et al., 1994). Increases in area of rice planted, rice quality, and paddy yield resulted (Brennan et al., 1994). Increased rice area, however, has led to the development of high water tables and risk of large tracts of land becoming salt-affected in southern NSW (Humphreys et al., 1994b). These concerns have led to various environmental regulations on rice in the region, culminating in 1994 when restrictions on rice area, soil suitability, and water consumption were fully enacted (Humphreys et al., 1994b). Strict environmental restrictions in combination with large areas of land make the management of this region a difficult task. Land managers require, among other things, a way of regulating water use, assessing or predicting crop area and productivity, and making management decisions in support of environmentally and economically sustainable agriculture. In the search for more time and cost effective methods for attaining these goals, while monitoring complex management situations, many have turned to remote sensing and Geographic Information System (GIS) technologies for assistance. The spectral information and spatial density of remote sensing data lends itself well to the measurement of large areas. Since the launch of LANDSAT-1 in 1972, this technology has been used extensively in agricultural systems for crop identification and area estimation, crop yield estimation and prediction, and crop damage assessment. The incorporation of remote sensing and GIS can also help integrate management practices and develop effective management plans. However, in order to take advantage of these tools, users must have an understanding of both what remote sensing is and what sensors are now available, and how the technology is being used in applied agricultural research. Accordingly, a description of both follows: first a description of the technology, and then how it is currently being applied. The applications of remote sensing relevant to this discussion can be separated into crop type identification; crop area measurement; crop yield; crop damage; water use/ moisture availability (ma) mapping; and water use efficiency monitoring/mapping. This report focuses on satellite remote sensing for broad-scale rice-based irrigation agricultural applications. It also discusses related regional GIS analyses that may or may not include remote sensing data, and briefly addresses other sources of finer-scale remote sensing and geospatial data as they relate to agriculture. Since a complete review of the remote sensing research was not provided in the rice literature alone, some generic agricultural issues have been learned from applications not specifically dealing with rice. Remote sensing specialists may wish to skip to section 2.

Optimising Agronomic Options At The Farm Scale

Thu, 03 Nov 2005 00:00:00 GMT

Optimising Agronomic Options At The Farm Scale Khan, Shahbaz; O'Connell, N; Xevi, E; Robinson, D Strategic planning and policy development for environmentally sustainable and economically viable management options for the rice based farming systems require the assessment of management options using mathematical models which integrate our understanding of water and salt movement with economic considerations at both the farm and regional scales. This project also had strong links with LWRRDC/MIL/CSIRO project on optimising irrigation intensities in the Murray Valley. During this project a standalone farm scale hydrological economic model SWAGMAN Farm (Salt Water and Groundwater MANagement) was developed and customised for situations in the Coleambally and Murray Irrigation Areas. The model processes were developed and refined by using feed back from irrigation managers, regulators and community groups. The following major achievements have been made: · Collection of crop, soil, irrigation, climatic and economic data sets for fourteen farms in the Murray Irrigation Districts · Rigorous validation of model processes by applying the model to fourteen farms with a range of enterprise, soil and groundwater conditions. · Development of simulation and optimisation modes in SWAGMAN Farm to assess environmental and economic impacts of existing and optimal cropping patterns · Various improvements of water and salt balance processes to suit conditions in the Murray Districts and the Coleambally Irrigation Area · Incorporation of soil water content accounting which provides flexibility in the representation of various starting soil profile water content conditions, water availability to crops and rational computation of recharge and watertable rise during the cropping and fallow periods · Development of a Windows based GAMS independent version of SWAGMAN Farm. GAMS (General Algebraic Modelling System) was an expensive software platform for the previous version with inflexible licence requirements. The new version written in C++ language uses Microsoft Access databases and will be linked with a GIS interface in near future. These sensitivity runs and model developments gained the confidence of members of the steering committee who provided vital inputs throughout this project. While considerable progress was made, they see the need for the work to continue to the stage where it can be applied to assist strategic planning and policy development, taking into account local regional conditions. Parallel to the modelling project an intensive paddock water monitoring project titled “Rigorously determined water balance benchmarks for irrigated crops and pasture’ was also initiated by the steering committee with the assistance of CSIRO, MIL, NSW Agriculture and LWRRDC. The purpose of the monitoring project was to further customise SWAGMAN Farm to local conditions and to validate the model results with the field data. Since monitoring projects take significant time in setting up and calibrating equipment, data analysis has only recently started, however initial comparisons of model results with the field results suggest that the improved SWAGMAN Farm can reasonably simulate field situations. However this work needs to continue to maximise the benefits of the paddock water balance monitoring. However, due to the wide range of groundwater, enterprise and soil conditions in the irrigation areas, SWAGMAN Farm needs to be applied to every farm to develop soundly based policy options. The need for application to individual farms is further driven by the complex regional groundwater interactions causing reversal (downward to upward and local discharge zones) of leakage rates in parts of the irrigation areas e.g. Murray Valley. This project has demonstrated that it is possible to develop methodology which helps assess optimal irrigation intensity within a multitude of biophysical and socio-economic constraints. The methods developed have scientific validity in capturing and representing key processes, and have community acceptance as a way of examining options that are important to them.

Better Prediction of Groundwater Recharge From Rice Growing

Thu, 03 Nov 2005 00:00:00 GMT

Better Prediction of Groundwater Recharge From Rice Growing Beecher, H. G A range of restrictions are associated with rice growing – land suitability, target rice water use, buffer areas and hydraulic loading limits. The Land and Water Management Planning process undertaken in southern New South Wales Irrigation Areas and Districts clearly identified the need to improve the rice land suitability criteria. Improvements to rice soil suitability criteria (including soil sodicity) are required due to the continuing restrictions to irrigation water availability, along with the need to limit recharge to regional groundwater systems. These criteria will assist irrigators maximize rice water use efficiency by allowing selection of the most suitable soils for rice growing. The Problem- Although the EM31 instrument, GPS and computer mapping technology have enabled significant improvements in the assessment of rice land to reduce groundwater accessions, modifications to the soil assessment process are needed. Cumulative infiltration during rice growing is known to vary significantly over four broad soil categories: self mulching clay soils, non self mulching clay soils, near levee soils and transitional red brown earths, there are also large differences in the level of infiltration within these soil categories (Van der Lelij and Talsma, 1978). Localised sites, which have high infiltration rates and thus allow high levels of groundwater recharge, may exist within rice fields and their delineation and exclusion or modification is an important aspect of rice land management in the southern Australian rice industry. Many of the soils in southern NSW are sodic. In sodic soils both swelling and dispersion of the soil occur. Swelling and dispersion reduce soil infiltration, permeability and ultimately deep drainage/ groundwater recharge. The Objective- The overall project aim was to improve rice land soil suitability identification and assessment approaches. The primary objective of this work was to investigate ways of refining the electromagnetic (EM) technology approach to include soil chemical characteristics specifically soil sodicity or exchangeable sodium percentage, in the rice land assessment process. Additional objectives were to: identify if the EM31 horizontal mode or EM38 provide better definition of the suitable rice land than the currently used EM31 vertical mode; and identify if land with ECa < 50 mS/m (EM31v) can be classified as unsuitable for rice without further determination of soil properties. The final objective was to promote adoption of the findings to date, particularly among irrigation company staff, DLWC regulatory staff and EM service providers to industry.

A Farm Scale Hydrologic Economic Optimisation Model To Manage Waterlogging And Salinity In Irrigation Areas

Thu, 03 Nov 2005 00:00:00 GMT

A Farm Scale Hydrologic Economic Optimisation Model To Manage Waterlogging And Salinity In Irrigation Areas Khan, Shahbaz; Xevi, E; O'Connell, N; Madden, J. C; Zhou, F Large parts of the irrigation areas of the Murray Darling Basin have shallow watertables that threaten crop productivity and financial sustainability of irrigated agriculture due to soil salinisation and waterlogging. Planning for environmentally sustainable and economically viable management of these problems requires the development, testing and application of mathematical models which can integrate our understanding of water and salt movement with economic assessment of different cropping decisions at a farm scale. These mathematical models can help in proper selection of agronomic and engineering options to reduce recharge to aquifers and rise of watertables and thereby minimise waterlogging and salinity problems. This paper gives mathematical details and sample applications of SWAGMAN (Salt Water and Groundwater Management) Farm, a farm scale hydrologic economic model that integrates agronomic, climatic, irrigation, hydrogeological and economic aspects of irrigated agriculture. Optimum land uses for a given farm are determined by optimising an economic objective function using mixed integer non-linear optimisation techniques. SWAGMAN-Farm has been applied to several farms in irrigated areas of southeast Australia. Model results show that for given hydro-climatic and irrigation conditions some land use types result in overall discharge from soil and groundwater while others induce groundwater recharge: a proper selection of crops can help reduce waterlogging and salinity problems and ensure economic viability of farms.

Measurement Of Losses From On-Farm Channels And Drains

Thu, 03 Nov 2005 00:00:00 GMT

Measurement Of Losses From On-Farm Channels And Drains Akbar, Saud Water use and groundwater rises are two important problems facing irrigators in the southern irrigated region of NSW. Water loss through percolation has been extensively studied for irrigated farms and major supply channels but there have been no studies of loss through on-farm channels and drains. This study aimed to determine the magnitude of percolation losses attributable to on-farm channels and drains. It also aimed to consider approaches and for need to identify problem were and to consider likely remediation techniques. Investigations were carried out within selected farms in Coleambally and Murrumbidgee Irrigation Areas in southern NSW during the irrigation seasons of 1997/98, 1998/99 and 1999/00. The Idaho Seepage Meter was used to make point infiltration measurements. Seepage losses were not estimated for all channels on every farm but for only those channels being used by the landholder in the periods seepage measurements were taken. Only 3 of the 9 farms investigated were using all of the channels and drains on the farm during monitoring activities. Only permanent channel and drain structures on the farm were measured. This potentially causes the annual seepage losses calculated per farm to be underestimated. The Idaho Seepage Meter was used for this investigation. Measuring seepage using the Idaho Seepage Meter is rapid, direct, and cheap. The success of this method depends upon the high degree of homogeneity in natural soils. Tests using seepage meters can be conducted in channels without interfering with their normal water delivery operation. Three or four measurements were taken across channels and drains at intervals of 50 - 100 metres. Due to the age and lack of maintenance of these channels their cross-sections had deteriorated. In these situations it was difficult to place the Idaho Seepage Meter on the sides of the channels. Extreme care was taken to cause minimal disturbance to the local soil so that the seepage pattern would not be appreciably affected. A series of test wells was drilled adjacent to the irrigation channels and drains using information obtained from EM 31 electromagnetic surveys. The Idaho Seepage Meter can be used to rapidly locate channel sections with high seepage losses. This enables total seepage losses from a section of channel to be estimated economically. The seepage results from 15-30 year old channels indicate that a combination of weeds and sediment deposition may be the major factor for reduction of seepage. Silt sediments were deposited on the channel bed, or on only part of the bed where the channel was curved, not the entire wetted perimeter of the channel. However, some old channels, which were cleaned prior to the irrigation season, had significant seepage volumes. In new channels and drains low seepage rates were also found at many sites. These sites could have been influenced by factors such as compaction beneath the bed of channel, soil sodicity, biological activity, and slope/bend of channel, and silt deposition in the channel bed. EM-31 surveys were used to characterize soil differences along channel and drainage lines and the apparent electrical conductivity (ECa) values were compared with direct seepage measurements using an Idaho Seepage Meter. This method proved successful in identifying actual seepage sites. ECa values obtained from the EM-31 surveys provided an insight into the most likely locations to have high seepage rates. The EM-31 method was shown to be an important initial predictive tool. Highest seepage rates were found where ECa values were low. In some areas seepage rates were found to be low despite low ECa values at these locations. These anomalies were attributed to various factors which included compaction of substrate, clay layers below channel bed, sodicity, biological activity and sediment deposition. Combining the seepage-monitoring program with the EM31 electromagnetic survey method proved to be highly effective in detailing the nature and extent of the problem. Despite its limitations, the EM31 method is considered to be an important predictive tool in the first stage of loss assessment. Investigation was carried out with in selected farms to quantifying seepage losses from sections of channels and drains in the Murrumbidgee Irrigation Area and Coleambally Irrigation Area. This study enabled those sections with high seepage rates to be identified. As the price of water becoming a realistic figure in terms of meeting actual cost, water distribution efficiencies are being very closely examined. Water loss through seepage in on-farm channels and drains is one of the many elements of the system under investigation. Detection and accurate measurement of seepage is important for the efficient and effective management of on-farm water. However, it is necessary to firstly determine whether a problem exists, and secondly to quantify the extent and seriousness of that problem, before putting resources into seepage control. At high seepage rates it is uneconomical to apply the various treatments available. It is suggested that only methods compatible with and complementary to the natural sealing process will be successful. Lining a leaky channel site will not always completely eliminate seepage losses. In fact, all that can be reasonably expected is a reduction in the seepage rate. The amount of reduction will depend upon the lining used and the magnitude of the loss prior to lining. Investigation sites were established within irrigation channels and drains on each of nine farms, each with an average of approximately 3-4km of unlined on-farm channels carrying water within the farm boundaries and about 1-3km of drains that are used for recycling runoff water.

Remote sensing of irrigated crop types and its application to regional water balance estimation

Thu, 03 Nov 2005 00:00:00 GMT

Remote sensing of irrigated crop types and its application to regional water balance estimation McVicar, Tim The strengths of moderate to coarse resolution satellite remote sensing in both identifying crop types and estimating crop area has resulted in the widespread use of this technology for agricultural monitoring. Although the spectral information and cost of these remote sensing data are attractive, their spatial resolutions are often perceived as being inadequate for agricultural management at both the individual holding and the paddock level in the rice areas of New South Wales (NSW). Conversely, fine resolution remote sensing (e.g., aerial photography) very often contain spatial detail that will allow management decisions to be made at the paddock level, but these data can be expensive to acquire and subsequent manual digitisation of crop areas is labour intensive when performed each year. This raises at least two associated research questions for the rice industry in southern NSW: (1) ‘how is the rice area best mapped when considering cost, accuracy, timing, and complexity while reconciling the above issues? ‘; and (2) ‘how can spatial accuracy (concerning both areas and positions) be measured and related to relevant management practices in order to influence decisions?’. Additionally, many operational users of remote sensing data perceive it as being an overwhelming data source as it often requires time consuming training and expensive computer software. This results in a further series of issues: (3) ‘can remote sensing be used operationally within the NSW rice industry so that simple methods can be applied using inexpensive software with minimal training in order to achieve similar or increased accuracies?’. Furthermore, use of spatially accurate GIS paddock boundaries has been shown to increase crop classification accuracy. However, this raises further questions: (4) ‘what is the influence of spatial error on management decisions?’; (5) ‘how can the accuracy of GIS data be measured?’; and (6) ‘how are these issues altered when considering the other major summer crops in the region?’. As satellite hyperspectral data (e.g., >100 spectral bands per image) are now available this again raises some questions, such as: (7) ‘does this extra spectral information content translate into additional or more accurate agricultural metrics’; and (8) ‘what is the current capacity in the rice industry of NSW to process this sort of information quickly as to impact management decisions?’. These and other related issues have made up the vast majority of the research from project 1105. Recommendations have been made wherever possible regarding the improvement of spatial analysis or mapping efficiencies. Importantly, the research from project 1105 has been adopted by the local industry – this is proof of ‘impact’ as opposed to only producing ‘outcomes’. The work reported here has concentrated on practical issues with an emphasis on transferring the knowledge gained to industry partners. Prior to addressing these issues, a comprehensive literature review concerning the utility of remote sensing in rice base irrigation systems was performed to ensure that past, present and current opportunities (and constraints) concerning the use of time series remote sensing in the local, national and international context were known and understood. Due to wanting to optimise research results by acquiring as many images as possible with our operating budget for image acquisition all new research (as opposed to the literature review) was conducted on the smallest irrigation areas in southern NSW: Coleambally Irrigation Area (CIA). Before methods can be transferred to the other irrigation areas (i.e., Murrumbidgee and Murray Valley Irrigation areas) some assessment of the similarities of the irrigation systems in terms of non-rice crops and their phenology needs to be performed.

Research Solutions To Watertable And Salinity Problems In The Rice Growing Areas Of Southern Australia

Thu, 03 Nov 2005 00:00:00 GMT

Research Solutions To Watertable And Salinity Problems In The Rice Growing Areas Of Southern Australia Humphreys, E; Beecher, G; Christen, E; Xevi, E; Thompson, J; Blackwell, J; Lewin, L The major threat to the sustainability of irrigated agriculture in the rice growing regions of the southern Australia is secondary salinisation as a result of rising watertables. Rice growing contributes about half of the accessions to the groundwater in these regions. A range of strategies for reducing the accessions from rice are applied, including restricting rice growing to soil assessed as suitable for rice. In the past this was based on soil texture, but increasingly EM- 31 survey is being used, and the inclusion of soil sodicity constraints will further improve the ability to predict suitable soils. The net evaporative demand for rice growing over the whole season is well-approximated by reference evapotranspiration (ETo), which is used to calculate the seasonal rice paddock water use limit. Potential methods for increasing rice water use efficiency and reducing recharge include shorter duration varieties and a range of water and soil management strategies. Intermittent and sprinkler irrigation can significantly reduce water use, however yields are also reduced due to cold temperature damage during early pollen microspore. Small areas of leaky soils can greatly increase total accessions to the watertable, and EM-31 surveys show that many “suitable” rice paddocks have leaky areas. Recharge from leaky areas can be reduced by puddling or by impact compaction. After rice harvest, soil water content is high, and recharge may continue, especially under the influence of winter rainfall and low evaporation. Research is underway to quantify the effect on accessions to the watertable of growing a winter crop immediately after rice harvest. Future work will investigate the conjunctive use of groundwater and surface water to promote watertable control while maximising agricultural productivity by making more water available for irrigation. The SWAGMAN (Salt Water And Groundwater MANagement) series of computer models has been developed to determine the impacts of management and climate on watertables, salinisation and yield, and the tradeoffs between environmental objectives and profitability. These models include SWAGMAN Destiny, a point scale crop model that can be run for up to 30 years of climatic data. SWAGMAN Farm is a farm scale optimisation model which predicts the most economic cropping mixes that meet specified net recharge and root zone salinity objectives, taking into account farmer preferences. Regional groundwater models have been developed to evaluate the impacts of climate and management on watertables. The development of shallow saline watertables results in the generation of saline drainage waters. Numerous evaporation basins ranging in size from a couple of hectares to a few hundred hectares have been created in recent years to receive saline drainage. Investigations into the salt and water balance of evaporation basins, the development of the model BASINMAN, and economic analyses have led to guidelines for the siting, design and management of evaporation basins. A pilot trial is also underway to investigate the feasibility of serial biological concentration, with the production of high value crops in the first 2 stages, followed by salt tolerant crops (stage 3), fish farming (4), evaporation basins (5) and a solar pond to generate energy.

Swiss Federal Institute of Technology (ETH). Visit Report Dr Shahbaz Khan

Thu, 03 Nov 2005 00:00:00 GMT

Swiss Federal Institute of Technology (ETH). Visit Report Dr Shahbaz Khan Khan, Shahbaz This report relates to a visit by Dr Shahbaz Khan to Professor Wolfgang Kinzelbach’s research group at the Swiss Federal Institute of Technology (ETH) from August 11-18, 2002. This visit was sponsored by the Rice CRC.

Trip report – ‘Water-Wise Rice Production’

Thu, 03 Nov 2005 00:00:00 GMT

Trip report – ‘Water-Wise Rice Production’ Thompson, John The workshop was jointly organised by IRRI (B Bouman and TP Tuong) and Plant Research International of Wageningen University and Research Centre (P Bindraban and H Hengsdijk). The workshop dealt with the problems caused by water shortage in rice production in Asia, and was represented by delegates from Water Workgroup of the Irrigated Rice Research Consortium, Water-Less Rice Project, Growing More Rice With Less Water, Groundcover Rice Production Systems and the Rice-Wheat Consortium. My attendance was encouraged and funded by the CRC as the workshop theme was particularly relevant to my project within Program 1 – 1204: ‘Strategies for improving the water use (efficiency) of rice. I was invited to present a paper titled ‘Water management of rice in southern New South Wales, Australia’.

Quantifying Impact Of Rainfall On Shallow Groundwater Table In The Wakool Irrigation District, NSW

Thu, 03 Nov 2005 00:00:00 GMT

Quantifying Impact Of Rainfall On Shallow Groundwater Table In The Wakool Irrigation District, NSW Wang, Butian; Khan, Shahbaz; O'Connell, Natalie Water table rise and salinity are major threats to the sustainability of agriculture in the Wakool area. In order to improve groundwater and salinity management in the Wakool area, it is necessary to quantify impact of both climate and management on shallow groundwater table. Rainfall as a major climate indicator and hydrology component plays an important role in regional hydrology and environment, as well as in water table change. This study attempts to quantify the impact of rainfall as a major climate indicator on shallow groundwater in the Wakool area based on the piezometric data in this area and the rainfall data in a wider area. GIS techniques have been extensively used in this study for data processing and analysis, especially for generating the spatial distributions of rainfall and groundwater table over the study period, for analyzing the spatial extent of groundwater table changes, and for calculating relevant volumes for various time intervals. This study has developed a method for isolating the impact of climate on shallow watertables. The method has been proven particularly effective in assessing the impact of rainfall for summer seasons which are the major irrigation periods in the study area. Statistical relationships were established to understand and quantify the impact of climate represented by rainfall on groundwater tables for different seasons in the year. The statistical relationships between rainfall and groundwater storage change derived from this study revealed some interesting bench mark rainfall figures: • For summer seasons, the bench mark rainfall is around 200mm, above which, it will likely to have an addition effect on groundwater storage; below which, it will likely to have a reduction effect on groundwater storage; • For the winter season, that bench mark rainfall is around 170mm The results of this study indicate that climate represented by rainfall, which is also a major source of flood, has a significant impact on the shallow groundwater tables in the Wakool area, as the correlations (R2) between rainfall and water table change are in the range of 0.7~0.9 for all the time intervals considered.

Travel Report, Study Tour Of Rice Production In South Korea And China (August 29 – September 21, 2002)

Tue, 01 Nov 2005 00:00:00 GMT

Travel Report, Study Tour Of Rice Production In South Korea And China (August 29 – September 21, 2002) Farrell, Tim Rice production has a long history in Korea and China and has substantially increased in recent times. These rises in yield reflect advances in hybrid rice technology, an improved plant type, better nutrient and farm management. During my visit many rice related issues of interest to Australia’s rice industry. In this report I have focused on reporting four key areas (climate change, cold tolerance, hybrid rice technology and aerobic rice) which I believe will have a major impact on rice production in Australia. It is vital that scientists around the world continue to collaborate on such areas to ensure global food security. Following my visit I am excited and looking forward to collaborating with scientists from Korea, China and others international organisations.

Report On A Study Tour To Examine Symptoms Of Rice Diseases In Southern USA And California

Tue, 01 Nov 2005 00:00:00 GMT

Report On A Study Tour To Examine Symptoms Of Rice Diseases In Southern USA And California Cother, Eric This was the first visit by a pathologist to look at rice diseases overseas since the industry started over 80 years ago. The purpose of my visit to the USA was to become familiar with current research into, and symptoms of, those diseases of rice that are potentially important in Australia. Whilst my major interest was in rice blast, I took the opportunity to look at all diseases that were present at the time.

CRC Program 2.3 Review Report

Tue, 01 Nov 2005 00:00:00 GMT

CRC Program 2.3 Review Report Batten, Graeme This report contains papers presented at a forum which was arranged to review progress made to date and set priorities for the 5th to 7th years of the Rice CRC Program 2.3. Professor Ross Welch, Chief Scientist with the USDA-ARS was a guest speaker and external reviewer for this assessment. The presentations included reports on completed projects, on work in progress in projects 2.3.1, 2.3.2 and 2.3.3, and on relevant work now in progress by CRC scientists in other programs and by Industry scientists. The papers in this report have been reproduced largely as presented on the day and readers who need more information should contact the authors directly (email addresses are included in the list of delegates). The review has highlighted the non-sustainability of rice production. Under current management practices, rice is mining soil N, P, K, and trace element reserves and is partly responsible for the accumulation of sodium in the profile. Burning of rice crop stubble is exacerbating the impact of rice production on soil nutrient reserves. The nutrient pools in the soil now clearly reflect the impact of rice production, especially on farms which have grown 20 to 30 rice crops since rice was first cultivated in the MIA 75 years ago. Field experiments have demonstrated that yields of some crops are being constrained by P and Zn deficiencies, irrespective of high rates of nitrogen application. Plant nutrient management has implications for grain quality. Nutrient concentrations are now available for Australian brown and white rice. These provide a valuable basis on which to compare data from overseas, local field and controlled environment studies. Program 2.3 has supported several studies on the micronutrient content of rice in the field and controlled environments. There has been an increased interest in trace elements in grain from consumers and human nutritionists. It was emphasized by Professor Welch that CRC Program 2.3 studies which address the links between nutrition and quality are very relevant. The macro and micro nutrient data also provided a basis for the discussion on the likely cause of the rice plant disorder known as straighthead. In addition to the yield loss caused by this problem, there are further implications for grain quality. Following the formal presentations, the topics of the review were summarized by Dr Lindsay Campbell who also highlighted some of the gaps in current knowledge of the rice system. This was followed by an evaluation of the program by Professor Ross Welch who also presented a general seminar titled “Harnessing the Power of Agriculture to Improve Human Health in Sustainable Ways”. The day concluded with a general discussion of key issues that led to the conclusions and recommendations for future research within the Rice CRC.

Participation in the XV International Symposium On Chironomidae, St Paul, Minnesota, And Study Tour To Washington State University

Tue, 01 Nov 2005 00:00:00 GMT

Participation in the XV International Symposium On Chironomidae, St Paul, Minnesota, And Study Tour To Washington State University Stevens, Mark This report summarises activities, findings and recommendations arising from overseas travel between Sunday 10 August and Monday 25 August 2003, during which time I spent approximately 5 days participating in the XV International Symposium on Chironomidae in St Paul, Minnesota, 2 days at the Washington State University Department of Entomology faculty meeting at Mt Vernon, and 7 days at the Washington State University Research Centre, Prosser. This trip has placed me in a better position to develop and deliver research programs designed to maintain the NSW agricultural industries at the forefront of both productivity and environmental sustainability. Specific recommendations arising from the travel include: Ø The development of research proposals aimed at determining the selectivity of rice bloodworm control treatments to Chironomus tepperi, the principal pest species attacking rice in NSW. Many of the bloodworm control treatments currently in use are likely to be killing a broad range of aquatic insects that are actually beneficial to the crop. Farmers have chosen these treatments in preference to more advanced approaches for many years, primarily due to their low cost, however in so doing they have potentially had a detrimental effect on invertebrate food chains within the rice agroecosystem. Because of the importance of aquatic food sources to terrestrial food chains, growers may obtain a greater benefit from more selective materials which, although potentially more expensive, may allow better conservation of non-target species. This will lead to higher incrop biodiversity and ultimately greater populations of both aquatic and terrestrial predators that will provide better natural control of pests such as mosquitoes and armyworms. Ø Invertebrate research programs in rice, conducted either for pest management or environmental assessment purposes, need to have a greater emphasis on community ecology and structure, rather than on just the populations of pest or indicator taxa responding to chemical applications. The multivariate analysis tools necessary or looking at community structure (multidimensional scaling, detrended correspondence analysis, etc) are now readily available in desktop statistics packages, and their use should be incorporated into all rice pest management proposals. Utilising these techniques will require additional sampling effort in field situations, and new research proposals should be prepared and resourced with these requirements in mind. Ø The development of a herbivore-induced plant volatile (HIPV) research program to evaluate the usefulness of these compounds for manipulating populations of beneficial insects in NSW crops. HIPVs are released by many crop plants in response to damage by pest species, and serve to attract predators (and potentially parasitoids) into crops that are experiencing damage. Many of the most common HIPVs have been identified by plant chemists, and studies at Washington State University have shown that lures placed in orchards, vineyards and hop-yards attract additional beneficial insects into these crops, enhancing natural biocontrol and potentially reducing the need for chemical control of pest species. Whilst HIPVs could be useful in rice crops, these materials show the greatest potential in low-input horticulture and viticulture. Grapes, citrus, and stonefruit are the most likely areas for HIPV use in NSW, however they may also be of benefit in organic agriculture and vegetable production. An initial trial program has been developed for the Yanco area, and the work will be conducted in collaboration with Associate Professor David James of Washington State University. Contacts made or renewed with other researchers at the XV International Symposium on Chironomidae (particularly Professors Arshad Ali and Xinhua Wang) are likely to lead to the development of future collaborative projects on chironomid ecology and management.

Travel Report Presented To NSW Agriculture And The Rice CRC

Tue, 01 Nov 2005 00:00:00 GMT

Travel Report Presented To NSW Agriculture And The Rice CRC Farrell, Tim Mr Tim Farrell attended the international conference on, The Impact of Agricultural Research for Development in Southeast Asia, in Phnom Penh, Cambodia, October 24-26, 2000. Mr Farrell then participated in an ACIAR workshop on, Productivity of Lowland Rice in Southeast Asia -Overcoming Environmental Constraints, in Vientiane, Laos, from October 30th to November 1st. During this visit, Mr Farrell made contact with a number of rice scientists working in similar areas of research.

Report On Study Tour To Japan, Italy, Canada And USA

Tue, 01 Nov 2005 00:00:00 GMT

Report On Study Tour To Japan, Italy, Canada And USA Batten, Graeme PURPOSE OF THE TRIP • To visit Aichi Prefectural Agricultural Institute, Japan to compare rice production techniques. • To present papers at the 9th International Conference on Near-Infrared Spectroscopy. • To visit McMaster University, Ontario Canada and the National Small Grains Germplasm Facility, in Aberdeen Idaho to learn methods being used to identify nutrient efficient genotypes of rice, corn and barley. • To gather germplasm for the Australian Rice Industry

Scoping Out A Socio-Economic Research Agenda For The Co-Operative Research Centre For Sustainable Rice Production

Mon, 31 Oct 2005 00:00:00 GMT

Scoping Out A Socio-Economic Research Agenda For The Co-Operative Research Centre For Sustainable Rice Production Chambers, Barbara; Spriggs, John; Dunn, Tony In May, 2000 the Co-operative Research Centre for Sustainable Rice Production (henceforth called the Rice CRC) commissioned Professor John Spriggs and Mr Tony Dunn from Charles Sturt University to write a paper called Scoping out a Socio-economic Research Agenda. In June 2000, Associate Professor Barbara Chambers, Director of the Institute for Regional Community Development at the University of Canberra was selected as a Research Associate for the project. The project was based on at least two assumptions. The first was that existing programs do not embrace a systems view of the rice industry, a significant omission given that the CRC is concerned with economic and social sustainability of rice farming in the irrigation areas. The second was that existing programs do not adequately involve producers in the change process required to respond to socio-economic challenges, especially technical research projects (Committee on Socio-economic Issues in the Rice Industry, CSU, December 14, 1999). In a philosophical sense, the dominance of scientific research has meant that the human dimension has often been ignored. A myth is perpetuated that facts and logical thinking will lead to changes in behaviour. But it is people that make decisions about how they will act, how they will respond to change and it is often attitudes and values that affect practice, not information per se. Socio-economic research attempts to address these dimensions, where there is a recognition that the affective (feelings and emotions) is at least as important as the cognitive (thinking) domain when people make important life decisions, such as in producer responses to market forces, salination, water reform and land use. In this context, 'socio-economic' research refers to the study of social and economic effects of policy decisions on people and communities. Changes in policy affect people's way of life, their cultural traditions, their community and their standard and quality of life. With this in mind, the aim of the current project is to focus on policy as it relates to irrigated agriculture in rice-growing areas of eastern Australia and hence to define a socio-economic research agenda for the Rice CRC. Our methodology is to develop a research framework and then use this framework as a basis for constructing the research agenda. We approached the task of building a research framework in four stages. First of all, we built an initial tentative framework from an initial meeting of the Socio-economic Committee of the Rice CRC. Second, we conducted an extensive literature search, including existing research reports and web-based data. Third, we undertook a number of semi-structured interviews with key informants. Finally, we revisited the initial tentative framework and modified it as dictated by the results of the literature search and interviews. The modified framework was then to be used to determine a proposed research agenda for the Rice CRC.

Sustainable Fumigation Practises

Mon, 31 Oct 2005 00:00:00 GMT

Sustainable Fumigation Practises Sigmund, Bronwyn The Australian rice industry must continue to meet customers' quality expectations, both domestically and internationally. These are controlled largely by Integrated Pest Management and Food Safety. Due to the phase-out of methyl bromide for all but pre-shipment and quarantine use it has been necessary to develop alternative fumigants for the disinfestation of durable food commodities. The phase out of Methyl Bromide has impacted the world heavily. The rice industry has been impacted heavily by drought, resulting in a reduced crop which makes each grain of extreme value to the business. Fumigation is highly necessary to ensure SunRice is delivering high quality products to our customers, and as a result relies heavily on successful fumigation. It is crucial that a replacement disinfestation method is found that offers equal or improved effectiveness in controlling pest infestation. The trials undertaken are both extensions on past trials that have given us confidence in their initial studies and new methods that give us hope that we may be able to reduce or replace the use of Methyl Bromide with another method of fumigation.; The Australian rice industry must continue to meet customers' quality expectations, both domestically and internationally. These are controlled largely by Integrated Pest Management and Food Safety. Due to the phase-out of methyl bromide for all but pre-shipment and quarantine use it has been necessary to develop alternative fumigants for the disinfestation of durable food commodities. The phase out of Methyl Bromide has impacted the world heavily. The rice industry has been impacted heavily by drought, resulting in a reduced crop which makes each grain of extreme value to the business. Fumigation is highly necessary to ensure SunRice is delivering high quality products to our customers, and as a result relies heavily on successful fumigation. It is crucial that a replacement disinfestation method is found that offers equal or improved effectiveness in controlling pest infestation. The trials undertaken are both extensions on past trials that have given us confidence in their initial studies and new methods that give us hope that we may be able to reduce or replace the use of Methyl Bromide with another method of fumigation.

Construction Of User-Friendly Plant Expression Vectors Using Rice Promoters

Mon, 31 Oct 2005 00:00:00 GMT

Construction Of User-Friendly Plant Expression Vectors Using Rice Promoters Upadhyaya, Narayana M; Blanchard, Christopher This project (3 months duration) was embedded within our ongoing projects on “Rice Functional Genomics”. A PhD student, Andrew Eamens was employed in this project to continue work on the development of user friendly plant expression vectors based on rice promoters. This work was started towards the end of Andrew’s PhD studentship. Using reporter genes containing a minimal promoter (enhancer trap) or intron splice acceptors (gene trap) in T-DNA or transposon tagging systems, several promoter sequences were identified by Andrew during his doctoral research and were used to produce plant expression vectors with tissue specific expression. The previously developed double right boarder (DRB) vector technology was used to construct a small group of user-friendly plant expression vectors with tissue-specific expression promoters. A new base binary vector construct (PDRB12dn) was constructed during this project period. The binary vector contained a promoterless reporter gene (sgfpS65T) mounted between the second right border (RB2) and the T-DNA left border (LB). The reporter gene is flanked upstream by a multiple cloning site (MCS) containing several unique restriction enzyme (RE) cleavage sites for easy cloning of putative promoter fragments. A total of 12 promoter fragments were also amplified by the polymerase chain reaction (PCR), ready for addition to the base vector. Cloning of individual promoter fragments is now in progress. The plant expression constructs being produced will enable the production of selectable marker free transgenic plants expressing GOIs in specific cells, tissues or organs.

Texture Analysis Of Rice Cakes

Mon, 31 Oct 2005 00:00:00 GMT

Texture Analysis Of Rice Cakes Martin, Rodney; Williams, Phillip Snack foods represent a dynamic segment of the food industry, as new products are continually being developed to satisfy changes in consumer trends. This highly competitive market features many products that have short life cycles, and a requirement for rapid development that puts pressure on aspects of the product development process such as shelf life studies, flavour profile development etc. Knowing a products limitations with respect to shelf life and storage is of critical importance before launching. In dry cereal foods, like rice cakes, breakfast cereals and extruded products, knowing the effects of storage on texture is of importance to ensure a high quality product reaches the consumer ...

New Applications For Rice Flour

Mon, 31 Oct 2005 00:00:00 GMT

New Applications For Rice Flour Williams, Phillip; Pan, Yu; Poulson, Vicki In recent years, the rice industry has faced many upheavals as a result of the continuing drought conditions we are experiencing. The effect on the rice growing industry has been staggering in regards to quantity and quality. As we have seen the effects of the drought worsen and the water level decade we have also seen rice crop sizes decreasing at a dramatic rate. This decrease has not been consistent throughout the varieties of rice currently grown in Australia due to the growing conditions required for some varieties and the availability of water in these areas. The aim of this project is to closely look at various attributes of rice in flour form in an aim to identify areas where different varieties can be used for rice flour production for new or the same purposes. This can potentially maximise rice usage and help ensure supply of rice flour requirements to consumers.

Improved Protocols For Isolated Microspore Culture Of Rice. Application Of Molecular Approaches To Rice Improvement.

Mon, 31 Oct 2005 00:00:00 GMT

Improved Protocols For Isolated Microspore Culture Of Rice. Application Of Molecular Approaches To Rice Improvement. Darvey, Norman A summary of this work is provided. The remainder of the original report has been withheld from publication as the information contained therein should be regarded as “commercial in confidence”. The main objectives of this project were (a) to develop a microspore culture based rapid breeding system (b) to understand the genetic basis of cold tolerance and (c) achieve genetic improvements in the cold tolerance of Australian rice germplasm. Thanks to the establishment of a special linkage with researchers in the Peoples Republic of China, some excellent cold tolerant germplasm was introduced into Australia. The cold tolerance of this germplasm has been confirmed by cold treatments under glasshouse conditions. This germplasm was then provided to several breeding, genetic, and physiological research groups within the CRC. Crossing has also been carried out between this germplasm and elite Australian cultivars in order to deliver doubled haploid plants for cold tolerance breeding and genetic research. Doubled haploid (DH) plant production is a way of rapidly fixing genetic segregation in the early generations of a crossing program, thereby reducing the number of years required for the establishment of pure breeding lines. Typically, DH plants of rice are normally produced by anther culture. As a result of this procedure, we have released over one hundred DH plants from a cross between the cold tolerant American cultivar M103 and the cold sensitive Australian cultivar Doongara. However, anther culture is a low efficiency system in that it is difficult to produce large numbers of DH plants. Microspore culture, on the other hand, is a highly efficient system which isolates young pollen from anthers, and gives rise to large numbers of DH plants in crops such as canola and barley. Microspore culture has also been reported in rice; however its efficiency of production has left much to be desired, especially with respect to cultivar response ...

Grain Quality In The Pre-Milling Phase

Mon, 31 Oct 2005 00:00:00 GMT

Grain Quality In The Pre-Milling Phase Sigmund, Bronwyn The rice processing sector has become more globally competitive in recent years. It has been an important part of SunRice’s business goals to raise our quality practices to a world leading standard. Quality assurance measurement and maintenance is a vital part of all operations, at every stage of rice production, from farm to consumer. Grain quality in the pre-milling phase has looked at many facets pertaining to improvements and optimisation of operations in the post-harvest phase of rice receival. Over the past few years these studies have allowed an understanding and adoption of best practice within SunRice operations. Of the many areas trialed, SunRice has adapted practices to accommodate those that have shown the ability to optimise cost benefits, enhance quality of grain and improve point of receival testing practices. Additionally, many projects have led to expansion in trials as have the learnings been adopted in other projects. The aims of the projects that have spanned the past seven years have provided growers with a better indication of crop quality during harvest and have allowed more effective segregation of paddy rice within SunRice storages. At point of receival, studies in crop quality such as trash, storage aeration, green grains, image analysis, and moisture variance have been explored resulting in improved testing methods and the ability to capture a greater understanding for segregation purposes. This allows SunRice to optimize the use of higher quality grain by reducing chances of contamination with lower quality grain. Additionally these studies have benefited the grower by providing a greater indication of their crop quality thought the harvesting process. Combined, a greater bearing on best practice has resulted, for the growing, storage and production of rice. More recent studies have concentrated on similar improvements in point of receival testing and storage quality optimization by grasping fresh advances in grain handling and technology. This has ensured stored rice is kept at the best possible standard. Overall, the greater understanding captured throughout these trials has largely benefited the sustainability of rice production.

Bloodworm Resistant Rice

Mon, 31 Oct 2005 00:00:00 GMT

Bloodworm Resistant Rice Hughes, Dr Peter The aim this project was to determine if it was feasible to control bloodworm infestations in rice using transgenic plants expressing an insecticidal toxin. Without control bloodworm can cause massive damage to the plant stand, up to 85% plant loss in years of high infestation. Currently bloodworm are controlled through the use of chemicals applied at the time the paddy is planted. The advantage of a transgenic plant approach is that it will eliminate, or at least severely reduce, the need for pesticide application and the consequent impact on beneficial insects and animals. Avoidance of pesticide application will improve water quality. We have shown that the insecticidal toxins from Bacillus thuringiensis israelensis (Bti) are toxic to bloodworm. Whole Bti was highly toxic to bloodworm with an LC50 of 45ng of toxin per ml of medium, which is a far greater toxicity than that of other Bt strains for their target insects. I have cloned the individual toxin genes from Bti and expressed five in Bt (cry4A, cry4B,cry10A, cry11A and cyt1A) and the relative toxicities of the individual toxins and their mixtures were determined. The most toxic protein was Cry11A, closely followed by Cry4B, with LC50s of 550 and 980 ng toxin per ml, respectively. After the identification of cry11A as a candidate gene, a construct was made to transform rice and test the expression of the native coding sequence. One callus line (of twenty) was found to contain detectable quantities of Cry11A protein. However, once regenerated into a transgenic plant this line does not express the toxin well. This was expected because native Bt cry genes are not well expressed in plant tissue because of the differing codon usages by Bt and rice and potential negative acting elements of the gene itself when expressed in another organism. A synthetic rice optimised gene was designed to increase the amount of protein produced within rice plants and so obtain plants with enough toxin production to be insecticidal. The synthetic gene was coupled to a strong constitutive promoter and transformed into rice to ascertain if sufficient expression could be obtained to kill bloodworm. Rice transformation was performed on callus, which is an undifferentiated lump of rice cells not capable of survival outside tissue culture. Ten transgenic callus lines were bioassayed at Yanco. All of the calli had at least some activity against bloodworm and two look to have very good levels of activity against bloodworm. This is significant for several reasons: The expression levels achieved are able to kill bloodworm, meaning that it is possible to express enough of the toxin to be lethal to insects. The resynthesised gene retains the toxicity of the parental gene. The large number of lines that are demonstrating toxicity indicates that even moderate expression in planta enables control of bloodworm at least in the laboratory. This gives a greater range of options for deciding on the level of expression acceptable in the field. The speed at which the insects die implies that they stop feeding quickly. In some insecticidal plants it takes days to stop feeding and die, in this time they are able to do considerable damage to the plant. With a rapid acting toxin, it is more likely that the damage caused between feeding and death will be minimal. 2 The demonstration of bloodworm activity is a major step forward and we are now in a strong position to continue the project, Plants expressing Cry11A have been generated and demonstrated to have high level bloodworm activity. All insects exposed to the Cry11Asyn transgenics were killed. A root specific promoter has been cloned and used to drive the expression of Cry11Asyn. Root specific expression is seen as a desireable characteristic because it limits the expression of the transgene in seed and therefore peoples exposure to Cry11A protein. Genes with potentially interesting expression profiles were identified through EST expression data in public databases, the expression pattern and level were experimentally determined using real time PCR and subsequently cloned. Expression analysis will be performed once plants are generated.

Targeting NIR Tissue Test Sampling Using Aerial Imagery And Identifying The Factors Causing Variable Rice Growth And Crop Yields.

Mon, 31 Oct 2005 00:00:00 GMT

Targeting NIR Tissue Test Sampling Using Aerial Imagery And Identifying The Factors Causing Variable Rice Growth And Crop Yields. Lacy, John; Evans, Peter; Steel, Felicity The new precision agriculture tool, aerial infrared images has created an opportunity for rice farmers to assess crop variability. At ground level variability is difficult to assess. Aerial infrared images readily show crop variability. The images supplied by Terrabyte Services show 5 colour image zones of crop vigour from low vigour to high vigour. The identified zones can show farmers where to sample crops for the NIR Tissue Test at panicle initiation. Previously farmers randomly sampled not really knowing whether the sampled areas were really representative of the crop. The ability of the aerial images to show crop vigour differences has led to the issue of how farmer crops compare to each other and what factors cause variability within crops. This project reports on the use of spatial infrared aerial imagery in the rice industry. It reports on two sub-projects. The first is the introduction and farmer use and adoption of aerial infrared imaging for identifying variability. The second sub-project reports on the identification of factors causing crop growth and grain yield variability. The outcomes from the first sub-project have been very successful. After the first season there was great feedback. Farmer quotes include: “There was more crop variation than I thought” “I was surprised by cut and fill areas showing up after 20 years” “The aerial images are an excellent tool at PI meetings” “The variation is often not due to nitrogen” 2 Over the first 2 years the number of farmer participants increased from 270 to 549, crop numbers from 484 to 834 and crop area from 14000ha to 29500ha. Although the 2005 rice crop area was lower at 44,000 ha compared to 65000 ha in the 2004 season, 29000 ha was imaged representing 66% of the total area. This compares to 47% in 2003/04. Perhaps the key outcome from the project is that aerial imagery has been successfully adopted by rice farmers and is now seen as an essential tool for improving the management of rice crops. The second sub-project has shown there is large yield variability and large factor variability within crops and between crops. The yield coefficient of variation (CV) of the monitored crops ranged from 4% to 76% in the 2003/04 season. The variation of measured parameters within the one crop eg plant number, water depth, N uptake has been surprisingly high with the CV often as high as 60-80%. There is a need to gain an understanding of the reasons for this variability which will be the subject of further analysis of the data. The future challenge for the rice industry and rice farming systems is to identify all the factors contributing to rice growth and yield variability and finding ways of overcoming the variability leading to more uniform and higher yielding crops.

Study Tour Report Institut National De La Recherche Agronomique (INRA) Joint Research Unit – Innovation, Montpellier, France (24-28 June 2002)

Mon, 31 Oct 2005 00:00:00 GMT

Study Tour Report Institut National De La Recherche Agronomique (INRA) Joint Research Unit – Innovation, Montpellier, France (24-28 June 2002) Brown, Andy This brief discussion paper documents key points arising from the Overseas Visit (24-28 June 2002) to the Institut National de la Recherche Agronomique (INRA) Joint Research Unit – Innovation in Montpellier, France1. The purpose of the visit was to: 1. Investigate the relevance of INRA agricultural extension practice to CRC Rice Project 5204; 2. Explore the potential for INRA – CRC Rice collaboration in agricultural extension. Key points arising from the visit are as follows: 1. Elements common to the French and Australian contexts of agricultural extension and rice production were identified during the course of the visit; 2. Social theory central to the research framework of CRC Rice Project 5204 was recognised as critically informing INRA agricultural extension practice; 3. INRA require an authoritative statement of CRC Rice intent in agricultural extension if the opportunity for collaboration is to be further developed.

Development Of Rice Milling In-Line Process Control

Mon, 31 Oct 2005 00:00:00 GMT

Development Of Rice Milling In-Line Process Control Hennicke, Owen SunRice’s Milling facilities were for the most part designed and built before the widespread use of computer based (Programmable Logic Controller or PLC) control systems. Over the years, PLC systems were introduced into the mills to improve the level of automation and reliability of process control. However, these systems did not incorporate all of the process control possibilities available. SunRice also required a more consistent and modern methodology to the human side of process improvement in general.

Organic Rice Production – Improving System Sustainability

Wed, 26 Oct 2005 00:00:00 GMT

Organic Rice Production – Improving System Sustainability Neeson, Robyn Trials conducted as part of the Cooperative Research Centre for Sustainable Rice Production during 2003-2004 investigated alternative weed management, cultivar assessments and fertiliser strategies in order to improve the sustainability of organic rice production systems in the NSW Riverina. Results indicated there was no immediate rice yield benefit to organic producers by applying any of the various organic fertilisers tested. Ongoing experimentation may have shown benefits to cereal or pastures which followed in the rotation, but this was not evaluated. The authors recommend that organic rice farmers carefully monitor crop yield responses to fertiliser applications and carefully consider the cost:benefit of fertiliser applications to their cropping and livestock rotation. Whilst the yields achieved for organic rice during the experiments were low compared to district averages for ‘conventionally’ grown rice during the 2003-04 season (yields ranged from 71-86% of conventional yield), they were well above the 50-75% yield reduction cited as typical for organically produced rice compared to conventional rice. The authors recommend that organic rice producers investigate a number of strategies to improve nutrient cycling within the rice rotation. This includes strategies to maximise symbiotic N fixation during the pasture phase such as shortening the pasture phase to two years, ensuring a high (at least 90%) legume component in pastures and improving pasture nutrition (particularly P), water use efficiency and grazing management. The value of incorporating green manuring within the farming system to increase N cycling, provide weed breaks and alternative cropping and grazing opportunities should also be investigated. Rice establishment techniques (sowing method, fertiliser placement and flushing) may have a significant impact on N losses and rice yields. Sod-seeding rice into a legume pasture, the method commonly used by organic producers, is the preferred sowing method for preserving organic nitrogen as there is zero cultivation and hence slow plant decomposition. Organic farmers can further reduce N losses during establishment by minimising flushing and by applying organic fertilisers or composts prior to permanent water (as opposed to sowing application). There was no statistical evidence that the application of liquid lime and molasses after sowing prevented the germination of some weeds, and that a homeopathic remedy made out of Barnyard grass seeds would decrease populations of barnyard grass over time. A field demonstration showed that harrowing could produce an effective post-emergent control for barnyard grass, providing the timing of harrowing and soil condition is optimal.

Risk Assessment Of Exotic Plant Diseases To The Australian Rice Industry, With Emphasis on Rice Blast

Wed, 26 Oct 2005 00:00:00 GMT

Risk Assessment Of Exotic Plant Diseases To The Australian Rice Industry, With Emphasis on Rice Blast Lanoiselet, V; Cother, Eric; Ash, G. J A pest risk assessment was carried out using all available information found in the literature and also two softwares developed by the CSIRO, CLIMEX and DYMEX. CLIMEX was used to assess the suitability of the climate in Australian rice growing area for each pest/disease and then when necessary and possible, a pest/disease model was created with DYMEX and run with Australian climatic data. The Australian climatic conditions and/or the rice growing practices were found to be unfavourable for the majority of the exotic diseases. However, two diseases of rice (rice blast and kernel smut) and one plant parasitic nematode genus (root nematodes) were identified as having the potential to threaten the Australian rice industry if ever introduced in south eastern Australia.

The Efficacy Of Rice As A Leaching

Wed, 26 Oct 2005 00:00:00 GMT

The Efficacy Of Rice As A Leaching Thompson, John; Griffin, Don The concluding phase(s) of a rice rotation experiment presented the opportunity to assess the effect of consecutive crops of rice on the chemistry of the soil profile. An experiment which aimed to determine the potential to use high salinity groundwater for the irrigation of the non-rice phases of a wheat - sub.clover - rice rotation, and then use rice, irrigated with low salinity channel water (<0.1 dS/m), as a leaching crop was undertaken. The rotation included a single rice crop between each cycle of the application of saline groundwater. Although soil salinity of most horizons under saline treatments could be reduced by leaching in the rice phase (single crop), this was not true for sodicity. Average rootzone sodicity remained elevated above control values at the end of each cycle and increased following successive cycles. This project was implemented to further assess the effectiveness of rice as a leaching crop. As the blocks completed two cycles within the rice rotation the opportunity to grow successive crops of rice was undertaken. At the time of soil sampling (May, 2000) separate blocks had grown one, two, three or four consecutive rice crops. Soil samples were taken from each plot and processed for electrical conductivity and sodium (Na) content. Additional consecutive crops of rice resulted in more leaching of salt from the profile. After three crops sufficient salts had been leached to reduce ECe to below 0.6 dS/m to at least the depth sampled in this project (90 cm). Similar values were measured after a fourth crop. The levels of SARe measured after a second consecutive crop of rice were still higher than pre-treatment levels. Even after three and four crops of rice the SARe at profile depths below 60 cm, whilst reduced from the pre-treatment level, were still between 6 and 8.

Molecular Basis Of Cold-Induced Pollen Sterility In Rice.

Wed, 26 Oct 2005 00:00:00 GMT

Molecular Basis Of Cold-Induced Pollen Sterility In Rice. Dolferus, Rudy Cold-induced pollen sterility is the most yield-affecting problem for the Australian rice industry,leading to yield losses of 20-40%,or A$15-29 million, on average every 3-4 years. The molecular basis of the problem remains largely unknown, and breeding efforts have been largely unsuccessful due to the lack of reliable selection techniques in the field/glass house, and the lack of molecular markers for selection of coldtolerant lines. Identification of the molecular basis of the problem may lead to the identification of markers that will greatly facilitate breeding of cold-tolerant Australian rice varieties. Our starting point was to study the accumulation of sucrose that occurs in anthers after cold treatment. We investigated whether cold affects expression of a gene involved in sucrose metabolism, thereby introducing a metabolic block in sucrose metabolism.

Screening Reproductive-Stage Cold Tolerance For The NSW Rice Improvement Program

Wed, 26 Oct 2005 00:00:00 GMT

Screening Reproductive-Stage Cold Tolerance For The NSW Rice Improvement Program Reinke, Russell A summary of this work is provided. The rest of the report will subsequently be the basis for information contained in a thesis to be produced by John Smith, Masters student. This project aimed at developing a clearly-defined and repeatable low-temperature screening protocol to enable selection for cold tolerance in the NSW DPI Rice Improvement Program. The series of trials identified a number of important issues that must be addressed when measuring tolerance to low temperatures during the reproductive stage of rice. The capacity of the controlled-environment glasshouse to maintain the temperatures necessary to induce floret sterility is extremely important, as small deviations from both maximum and minimum temperatures can influence floret sterility. The controlled-temperature facility used at Deniliquin had limited capacity to maintain low temperatures during periods of high ambient minimum temperatures. The glasshouse in which plants are raised before and after cold treatment must also have good temperature control so that cold damage is not induced during these periods. Factors other than temperature also influence floret sterility, and this project demonstrated an effect of the position of the pot within the glasshouse, as well as an effect associated with plants were completely surrounded by others or at the edge of the plant canopy ...

Minerals For Sustainable Grain Yield And Grain Quality.

Wed, 26 Oct 2005 00:00:00 GMT

Minerals For Sustainable Grain Yield And Grain Quality. Batten, Graeme; Campbell, Lindsay Rice cropping is an intensive enterprise. To be sustainable and to use water efficiently, rice requires adequate plant-essential nutrients. Nutrient supply has an impact on both grain yield and grain quality. In this project we have developed a nutrient balance model which summarises the impact of rice cropping on soil nutrients. The main concerns highlighted from this model are that, on average, all soil nutrients, except sulphur and calcium are being depleted. This work should alert rice growers to the potential for yield losses due to nutrient depletion. A plant nutrient diagnostic protocol is still required for Australian rice varieties. A protocol has been developed to induce the yield-reducing disorder known as straighthead. This will facilitate the design of studies aimed at understanding the cause of this problem. The current theory being tested is that micronutrient deficiencies, e.g., copper or zinc, cause the problem. Further testing is required to confirm the findings made up to now. This project has also demonstrated for the first time, that grain Fe and Zn can be increased in rice grains by as much as 44 and 26% respectively following applications of these elements in foliar fertilizers. During this study we also demonstrated the value of non-contaminating grain processing equipment for use in the study of micro-nutrients in rice. Variation in germplasm is seen as an asset to the breeding program. A literature review of world data from non-cultivated species of the genus Oryza has been assembled and will be a valuable source of information for plant breeders and other scientists seeking specific traits. During this study we also developed a new taxonomic key to aid the correct identification of the 4 Oryza species which are found in Australia. Rice accumulates phosphorus (P) to about 0.35% by weight in brown grains. As 85% of Australia’s rice is exported we sought germplasm to reduce this loss. Samples we obtained from a long-term study in Japan clearly demonstrated the impact of P-deficiency on grain yield and grain quality (low P, K and Mg concentrations). Preliminary studies were made at Yanco of the mutant rice known as lpa-1. The key feature of lpa-1 is that it deposits more phosphorus into inorganic P but less into organic or phytate P in the grain. We suggest that the line lpa-1 should be incorporated into high yielding Australian rices to produce a rice which could provide a better nutrient intake for humans and monogastric animals. Linkages have been established with the Yezin Agricultural University in Myanmar and the rice program of the Central Agricultural Research Institute. These linkages have the potential to boost our understanding of the nutrient requirements of rice under long-term cultivation and also provide access to cold-tolerant germplasm from regions with higher altitudes. This report represents the end of research supported by the Rice CRC . Project 2302 has enabled us to better understand the importance of nutrients to sustainable rice production but, at the same time, has left many promising lines of research worth further study.

Molecular Basis Of Cold-Induced Pollen Sterility In Rice

Wed, 26 Oct 2005 00:00:00 GMT

Molecular Basis Of Cold-Induced Pollen Sterility In Rice Dolferus, Rudy We have used two approaches to study the molecular basis of cold-induced pollen sterility in rice. Firstly, we studied the effect of cold on sugar metabolism in rice anthers, with the intention to identify genes that are affected by cold. Secondly, we used microarray gene expression profiling to identify rice genes that are affected by cold treatment, and to compare the cold response between a cold-tolerant and a coldsensitive variety. The work on sugar metabolism has shown that cold treatment of rice anthers leads to an absence of starch accumulation and non-viability of pollen. Starch is an essential source of energy for pollen development and pollen fertility. At the same time, we found that sucrose – the building block of starch – is accumulating in cold-stressed anthers at the cold-sensitive young microspore stage. This indicates that sucrose somehow fails to be converted to starch in the pollen grains, and that the supply mechanism of sugar to the tapetum and developing pollen grains is disturbed by cold. The tapetum, the cell layer in the anther that feeds the pollen grains, and the pollen cells are physically isolated from the rest of the anther at the young microspore stage. Supply of sugars from the rest of the anther to the tapetum and pollen grains occurs via a specialised mechanism involving two enzymes: cell wall invertase and monosaccharide transporters. Biochemical analysis indicated that the activity of anther cell wall invertase was significantly repressed by cold, suggesting that the first step in the sugar transport chain is functioning at reduced capacity. We cloned the gene that encodes this enzyme, OSINV4, and found that the expression of this gene is repressed by cold. We subsequently identified two monosaccharide transporter genes: OSMST8 was repressed by cold, while OSMST7 was induced by cold. OSINV4 and OSMST8 function in the same pathway that supplies sucrose to the tapetum and pollen, while OSMST7 functions in a different pathway that may lead to starch accumulation in the anther wall. Studying the cold-tolerant Chinese cultivar R31 revealed that this cultivar did not accumulate sucrose, contained starch-filled fertile pollen grains, and did not repress OSINV4 and OSMST8 expression following cold treatment. Thus, there is a strong correlation between these phenotypes and the cold tolerance phenotype, suggesting that we have now some expression markers for coldtolerance. We have also found that these genes are regulated by the plant hormone ABA; ABA perfectly mimics the effect of cold and it serves as a signal to switch of gene expression, including OSINV4 and OSMST8. ABA-accumulation does not occur to the same extent in R31 than in Doongara, and we have identified an anther ABA biosynthetic gene that is induced by cold (OSNCED3). These findings have improved our understanding of the molecular basis of cold-induced pollen sterility significantly, and we are now in the stage of identifying a marker gene that can be used to follow the cold-tolerance trait in a breeding population. We have also made good progress using the microarray approach. By comparing the cold response of Doongara and two tolerant cultivars (R31 and R32) we identified a non-redundant set of 329 genes that are expressed differently between the different cultivars. The genes were sequenced and their chromosome location was determined. This gave us more information about other cellular processes that are affected by cold and how these processes are affected differently in tolerant and sensitive cultivars. We are now in the stage of spotting these genes on a smaller diagnostic microarray, and this array will be used to screen doubled haploid lines of a Doongara/R31 cross (prepared by Dr. X. Zhao, Sydney Univ.). This will enable us to identify suitable marker genes for cold tolerance in rice.

Cold Physiology At The Plant Level

Sat, 01 Jan 2005 00:00:00 GMT

Cold Physiology At The Plant Level Subasinghe, Ranjith; Bechaz, Kathryn (nee Fox) Low night temperatures during late January and early February coinciding with early pollen microspore (EPM) development of rice (Oryza sativa) is a major factor limiting productivity in the Riverina region of New South Wales (NSW). This project primarily examined genotypic differences in cold damage that are associated with low temperature during reproductive development. The objectives were to: (1) investigate the effects of low temperature on physio-morphological traits of rice plants, with particular emphasis on reproductive traits; (2) examine the consistency of expression of cold tolerance in different screening environments; and (3) quantify the effects of temperature and daylength on the phonological development among cultivars. Results from three screening environments including temperature-controlled rooms, a cold water facility and field experiments are reported. Over 50 cultivars from diverse origins, including cold tolerant cultivars from Eastern Europe, Japan and California were screened. Cultivars were exposed to day/night air temperatures of 27°/13°C in temperature-controlled rooms and a constant temperature of 19°C in the cold water facility. Exposure time for plants was from panicle initiation (PI) to 50% heading. To increase the likelihood of inducing cold damage in field experiments, several techniques such as multiple sowing dates, shallow water depths (5cm) and high nitrogen rates (300kgN ha-1) were used. The three screening methods induced sufficient levels of spikelet sterility to identify genotypic differences and consistently categorise cold tolerant cultivars. Among the common cultivars there was a highly significant relationship for spikelet sterility between temperature-controlled rooms and field experiments (r2=0.52, p<0.01, n=31), temperature-controlled rooms and the cold water facility (r2=0.63, p<0.01, n=21) and the cold water facility and field experiments (r2=0.53, p<0.01, n=21). Screening for cold tolerance in temperature-controlled rooms or the cold water facility was preferred to field screening because of the reliability of exposure to low temperature in both environments. However, it is still important to combine a controlled environment screen with field observations since some cultivars varied in their response under different screening methods. Several flowering traits such as the number of engorged pollen grains per anther, anther length and anther area produced significant genotypic variation and were negatively related to spikelet sterility at maturity. When low temperature coincided with reproductive development Australian and Californian cultivars were inefficient at producing filled grains, despite them having a similar number of engorged pollen grains and similar sized anthers to cultivars from other origins. This inefficiency may be partly related to a small stigma area. Several cold tolerant cultivars (M103, HSC55, Plovdiv 22, M104 and Jyoudeki) and cold susceptible cultivars (Sasanishiki, Doongara, Nippon Bare, Sprint and Reiziq) were identified. However, many of the cold tolerant cultivars had a shorter growth duration leading to lower yield potential compared to commercial cultivars. Therefore, two shorter duration cold tolerant cultivars, HSC55 and Plovdiv 22, were hybridised with two NSW commercial cultivars, Illabong and Millin, to determine if cold tolerance could be improved. The progeny were evaluated for cold tolerance in temperature-controlled rooms and there was found to be no relationship between 2 growth duration and spikelet sterility. Although, it should still be possible to produce cold tolerant cultivars with appropriate growth duration for Australian conditions. Phenological development was examined in sequentially sown field experiments by exposing plants to low temperatures and providing several different temperature and daylength conditions. Amaroo and Millin were identified as mildly photoperiod sensitive, whilst M103 and HSC55 were found to be photoperiod insensitive. A crop phenology model was developed for Amaroo and used to predict an optimum sowing date based on historical weather data from 1955 to 2002. The model minimizes the possibility of exposure to low temperatures during the young microspore and flowering stages. The analysis indicated that the 15th October was the optimal sowing date for Amaroo. Nevertheless, sowing up to November 1st when seasonal temperatures are average also minimizes the risk of encountering low temperatures. Increasing the photoperiod sensitivity of cultivars above that of Amaroo may further reduce the risk of encountering low temperatures and at the same time increase sowing flexibility. Results from this project have improved our understanding of the mechanisms of genotypic response to low temperature during reproductive development and provided methods to develop cold tolerant cultivars.

Allelopathy And Weed Competition

Tue, 25 Oct 2005 00:00:00 GMT

Allelopathy And Weed Competition Seal, Alexa N Currently, only two herbicides, Londax® (bensulfuron) and Taipan® (benzofenap) are available for the effective control of all four major broadleaf weeds infesting NSW rice paddocks. Prolonged and widespread use of these two herbicides in the rice growing regions increases the threat of herbicide resistance. The low likelihood of new herbicides in the foreseeable future increases the impact of herbicide resistance on the Australian rice industry. Allelopathy, chemical interactions between plants, is an alternative control option. Weeds could be controlled by using crops which have been developed to exert their own weed control by releasing chemicals into the soil. These naturally occurring compounds could play a valuable role in an integrated weed management system, potentially reducing the amount of synthetic herbicides required for weed control. In rice, the potential use of allelopathy in weed control has been explored by several researchers worldwide. Funding for work on allelopathic potential was provided by the Rice CRC as they recognised that the Australian weed community is very different and many of the weeds infesting rice paddocks are typically Australian problems not likely to be tackled by international research groups. Twenty-seven rice cultivars were examined in the laboratory for their allelopathic potential against several currently important and potentially important rice weeds in Australia, namely barnyard grass (Echinochloa crus-galli), dirty dora (Cyperus difformis), lance-leaved water plantain (Alisma lanceolatum), starfruit (Damasonium minus), arrowhead (Sagittaria montevidensis) and S. graminea. Weed root growth inhibition ranged from 0.3 % to 93.6 % of the control depending on the cultivar and the weed species being tested. One weed was actually stimulated by Langi. Several rice varieties significantly inhibited root growth of more than one weed. A field trial using starfruit as the test species was conducted to see if those cultivars which inhibited starfruit in the laboratory experiment also inhibited starfruit in the field and to determine whether allelopathy was an important factor in the resulting field performance. Twenty-four cultivars were used in a field trial based at the Yanco Agricultural Institute. Starfruit dry matter was measured as an indicator of weed inhibition. It was found that there was a correlation between laboratory and field results, and that allelopathy was an important contributor to field performance of a rice variety.

Investigating Links Between Minerals In Rice Grain And Straighthead

Mon, 24 Oct 2005 00:00:00 GMT

Investigating Links Between Minerals In Rice Grain And Straighthead Williams, Phillip Straighthead or “Parrot Beaking” is a “physiological” disorder causing distortion and a high proportion of missing grains on the rice panicle. Crop losses range from 10 to 30% in medium grains and as high as 90% in short and long grains. Straighthead has been recorded in NSW rice crops since 1960s. It occurs in both the Murrumbidgee and Murray Valleys and the Coleambally Irrigation Area. Straighthead also occurs in Arkansas, Lousiana and Texas in the USA and in other countries who use other words to describe it. There is no known cause of Straighthead although it can be induced in the glass house by addition of arsenic based compounds and straw or sugar to the soil. In Arkansas Straighthead is associated with the use of arsenic based herbicides used in cotton during rotation. Straighthead is thought to be a relatively minor problem in the NSW rice area as a whole but can be devastating to individual growers who have the problem. However, its true extent is unknown because it is often confused with cold weather sterility and may occur at low levels unnoticed in many crops. Straighthead is thought to be related to soil conditions and is not seed borne or transmitted around the farm. The symptoms of Straighthead are upright panicles, with misshapen hulls of affected grains – often called “Parrot Beaking”. This effect is most pronounced in long grain. Medium grains tend to have some misshapen grain but not all “parrot beak”.

A Strategic Soil Nitrogen Test For Flooded Rice

Sat, 01 Jan 2005 00:00:00 GMT

A Strategic Soil Nitrogen Test For Flooded Rice Angus, J. F From 1998 until 2002 a project to develop a soil nitrogen (N) test for flooded rice was conducted in the Rice CRC. The reason for wanting such a test for the Australian rice industry is that N fertiliser is used more efficiently when applied before sowing so it is economically and environmentally preferable for as much as possible of the optimum amount of N fertiliser to be applied at that time. However excessive N applied before sowing leads to a high risk of yield loss due to cold damage. The aim was to develop a system to forecast the optimum N supply for pre-flood application and minimize the amount being topdressed which has been a safe, but inefficient system. The method of developing the test was first to compare the near infrared reflectance (NIR) spectra with crop productivity and N mineralisation measured by wet chemistry. These measurements were made with soil from 22 previous experiments measuring yield response to N applied at sowing. There were close relationships of the NIR spectra with crop productivity and N mineralisation but because of the small data set the relationships had little predictive value. However the close relationships found between NIRS, N mineralisation measured in the laboratory and crop performance encouraged us to proceed with further studies. A more detailed study related soil mineralisation across farms to crop performance. Seventeen methods of mineralisation were tested and the most reliable was found to be anaerobic incubation at 40°C for 21 days. This method predicted the optimum N requirement with a standard error of about 75 kgN/ha, which is clearly unsatisfactory for an industry where the average amount of N fertiliser applied is 145 kgN/ha. A possible reason for the low correlation between mineralisation and crop performance was that other factors were limiting N response. There was some evidence that sowing date and deficiencies of other nutrients were partly responsible for the variability of the N response. However it is unlikely that including information about these factors would lift the soil-N test to acceptable accuracy for commercial use. The most likely reason for the low correlation was that the soil depth used for mineralisation measurements was poorly defined because of the widespread levelling of rice fields which led to different depths of topsoil. Two options are proposed for more reliable application of N fertiliser at the time of sowing. Both require further research. One is to use the existing soil test only to identify soils with large amounts of potentially mineralisable N. Such a test could be the basis of a recommendation to apply little or no N fertiliser before sowing. Rice growers would still have the option of topdressing N fertiliser at the panicle initiation stage. The advantage of using a test in this way is that it is most unlikely to result in ‘false positives’, i.e. - recommendations for excessive N fertiliser leading to yield reductions. The other option is to set up a system of zone management for N fertiliser based on the likely N mineralisation in different parts of a rice field. The results in this project suggest that yield responses are more accurately predicted by sodicity than by the soil N test. It is likely that sodicity is a good indication of the depth of topsoil cut in the process of levelling. If this result is shown to be general, maps of ‘cut and fill’ areas may help in deciding the optimum amount of N fertiliser. Evidence from the Ricecheck database shows that about 10% of rice paddocks receive too much N fertiliser at sowing and suffer a large yield reduction. This leads to an annual loss of about $18 m. While this project has not led to a solution to this problem, the two suggestions arising from the project offer methods to reduce the problem.

Quantifying and Maximising the Benefits of Crops After Rice

Sat, 01 Jan 2005 00:00:00 GMT

Quantifying and Maximising the Benefits of Crops After Rice Humphreys, E; Smith, D. J; Fattore, A; Bhuiyan, A. M; Fawcett, B. J At the time this project was conceived, rising watertables and subsequent salinisation were considered to be the major threats to the sustainability of irrigated agriculture in the rice growing areas of southern NSW. The biggest threat to sustainability at present is the reduced availability and higher cost of water as a result of the water reforms, and more recently prolonged drought. The hypothesis of this project was that growing crops immediately after rice would increase water use efficiency and profitability of rice-based cropping systems while reducing net recharge. Field experiments were conducted from 1998 to 2000 on two soil types to evaluate the effect of non-irrigated wheat after rice on watertables and net recharge. Rainfall during the wheat season was reasonably similar in all 3 years (270-318 mm) and higher than average (220 mm). Yield and biomass production of early sown (24 April) wheat were higher than yield of late wheat (29 June) (grain yield 4.7 vs 3.8 t/ha at 12% moisture). In the absence of irrigation, the soil profile remained wet in fallow areas, whereas there was considerable drying in areas planted to wheat. The drying created capacity in the soil profile to capture and use winter rainfall. There was a general increase in depth to the watertable during the first half of the season where non-irrigated wheat was grown after rice, but not in the fallow areas. However, in all situations, the watertable rose around the time of rice sowing each year due to a rise in the regional groundwater level. The lumped water balance studies suggested net discharge of about 1 ML/ha between the time of sowing and harvesting wheat after rice in each of the three years, mostly due to higher upflow due to crop water use. In the fallow, net discharge/recharge was close to zero. The CERES Wheat and SWAGMAN® Destiny models performed very well in simulating a wide range of crop and soil water parameters, although the validation data sets were limited in that the yield range was smaller than desirable. Consistent with the field studies, yield of nonirrigated early sown wheat (median 3.8 t/ha) was usually much higher than yield of late sown wheat (median 1.8 t/ha). With one or two irrigations yields of both early and late sown wheat almost always increased, by around 1 t/ha with one irrigation at heading, and an additional 0.5 t/ha with a second irrigation during grain filling. It was only with frequent irrigation (whenever cumulative ETo-rain since the previous irrigation reached 60 mm) that yields of late sown wheat matched (or surpassed) yields of early sown wheat. However, the irrigation requirement for late wheat irrigated at ETo-rain 60 mm was almost always much higher than for early wheat with the same irrigation management (by >100 mm in most years). While irrigation increased yield, it also increased net recharge, with final watertables generally higher by 0.5 to 0.8 m for wheat after rice (wet initial soil) with irrigation at ETo-rain 60 mm compared with no irrigation. The model simulations showed that with wheat after rice, there was net discharge in almost all years, regardless of initial watertable depth (0.5-1.5 m). In comparison, net recharge occurred in 18 to 48% of years with fallow after rice, the amount of recharge increase as initial depth to the watertable increased. For non-irrigated wheat after rice, salinity of the watertable was 2 important where the watertable was shallow (0.5 m), with yield reductions in excess of 1 t/ha in most years. However for deeper watertables, there was no effect of watertable salinity for non-irrigated wheat. With irrigation, watertable salinity had no impact on yields. Growing wheat immediately after rice was financially beneficial, with an increase in Net Present Value (NPV) ranging from 31 to 126 $/ha/yr depending on the rotation. Assuming that the rate of adoption is doubled over 20 years as a result of the project, the NPV of benefits was estimated to be $5.6 million compared with costs of $1.1 million, resulting in a benefit cost ratio of 5.3.

Understanding Amylose Structure, What It Controls And What Controls It.

Thu, 20 Oct 2005 00:00:00 GMT

Understanding Amylose Structure, What It Controls And What Controls It. Fitzgerald, Melissa; Blanchard, Christopher Starch accounts for at least 92% (dry weight) of a milled rice grain. Starch is comprised of two fractions, amylose and amylopectin. Amylose content can range from 0% (in waxy rice) to about 30%. Amylose is essentially a linear molecule ranging from about 800 degrees of polymerization (DP) to about 10 000 DP. It carries a few widely spaced chains. Amylose plays a significant role in almost all of the cooking qualities of rice. The process of cooking of rice begins with the softening of the starch granules, which is primarily a function of amylopectin. The next process, swelling, is greatly affected by amylose. As the starch granules swell, amylose leaches from the granules into the solution phase. Behaviour observed in the field of synthetic polymer science suggests that the linear amylose molecules surround the swelling granules and inhibit the swelling. After amylose leaches from granules, it joins the continuous phase and van der Waal forces inside the helices of chains cause double helices to form. The double helices aggregate into a gel; the more double helices, the firmer the gel. The early stages of gel formation would occur in the interval between removing from heat and eating the rice. Long chains of amylose have a higher viscosity than short chains, and this limits the mobility of the long chains. Thus, with long chains, the formation of double helices and aggregations is slower, leading to a softer gel. Therefore, amylose structure could explain why two varieties with the same amylose content differ in cooked texture. In the later stages of gel formation, typically occurring well after cooking the rice, and when the temperature falls below 25 ºC, short chains of amylose will form double helices and crystallites much more readily than long chains of amylose. Therefore, rice that contains short chains of amylose are likely to be hard when cooled after cooking. The knowledge and information that could be provided by developing a method to measure amylose structure will provide a tool allowing greater insights into the effect of amylose structure on different cooking properties, with the ultimate aim of developing the knowledge into a selection tool for rice breeders. After developing a tool to measure amylose structure, it was applied to understanding a particular nutritional property of rice, namely resistant starch. Literature and early research indicated some link between resistant starch content and amylose content, however, detailed investigations of the structure of resistant starch, hypothesised to reveal more of the secrets of amylose, in actuality, revealed some of the secrets of amylopectin.

Improving the Water Use Efficiency of Rice - Final Report

Thu, 20 Oct 2005 00:00:00 GMT

Improving the Water Use Efficiency of Rice - Final Report Thompson, John; Griffin, Don; North, Sam The cost of irrigation water accounts for 20-30% of the total variable costs of rice production in the Murrumbidgee and Murray Valleys. Rice production consumes a substantial proportion of the available supply of irrigation water. Any agronomic/water management practice that has the potential to reduce water use should be investigated. Research in the Burdekin River Irrigation Area indicated that crop water use of rice grown on raised beds was 32% less than when grown using conventional permanent flood. Whilst recognising that there are likely to be agronomic constraints to rice production on raised beds in the Riverina, investigations into potential water savings, were investigated in this project. The project evaluated the water use efficiency of rice grown on a raised bed layout on two of the principal soil types used for rice production (four experiments). This layout was compared with the now traditional aerial sown fully ponded flat layout. The opportunity to explore water management options on the raised bed layout was also undertaken in three of the experiments. Water use was quantified and agronomic performance of the rice crop monitored. Maintaining water in the furrows all season reduced grain yield by an average of 10% (range 7-20). In three of the four experiments harvest index was lower where water was maintained only in the furrows. Moisture stress during panicle development and grain filling may have contributed to this result. Although sterility was not measured, no affected panicles were observed. Water use, where water was maintained in the furrows, was reduced by 14% (range 7-18). Water use efficiency increased on two occasions but decreased on one. Efficiencies for the two irrigation layouts by water management treatments of most interest (water maintained in the furrows; fully ponded flat) ranged only from 7.1 to 8.1 kg/ha/mm of water used by the crop. Despite an apparently similar soil type across the experimental areas, considerable variation in water use between plots with the same water management was measured. When attempting to measure water use in ‘small plots’ it is recommended that there be a minimum of four replications and/ or differences in water management between treatments be substantial. This project demonstrated that rice can be successfully grown on the raised bed layout (yields > 10 t/ha). Reductions in water use will not be as substantial as those reported from Queensland. Where water ‘subs’ readily to the centre of the raised bed grain yield, water use and water use efficiency are all likely to be similar to the traditional fully ponded flat layout.

Strategies for Improving the Water Use Efficiency of Rice

Thu, 20 Oct 2005 00:00:00 GMT

Strategies for Improving the Water Use Efficiency of Rice Thompson, John; Griffin, Don The cost of irrigation water accounts for 30-38% of the total variable costs of rice production in the Murray and Murrumbidgee Valleys. Rice production consumes a substantial proportion of the available supply of irrigation water. Any water management practice that has the potential to reduce water use and/or increase water use efficiency should be investigated. This project evaluated two approaches that may increase water use efficiency of rice – delayed flooding and a water management strategy termed mid-season ‘drain’. Water use was quantified and agronomic performance of the rice crop monitored. Delayed flooding involves intermittent irrigation of the crop until about ten days prior to panicle initiation. The scheduling (and number) of intermittent irrigations will be determined by the growing season temperatures. In the experiments reported here the combine sown treatments received eight irrigations as well as the first flush which initiated germination. The aerial sown treatments received three or four irrigations once the crop had established. The time taken for establishment (3-4 leaves) ranged from 34-43 days. Mid-season ‘drain’ involved removing surface water from the crop for about seven days towards the end of tillering. The rice plants experience visible moisture stress before the flood is re-applied. Plots grown with delayed flooding produced equivalent yields to the fully ponded control. Water use was reduced by 8-18%; thus water use efficiency was increased. Mid season ‘drain’ increased grain yields by 6, 10, and 9% for the three growing seasons covered in this report. Whilst none of these increases in yield were statistically significant there is sufficient evidence of an increase in grain yield when the crop experienced a mid-season ‘drain’ to warrant further investigation. In commercial crops, when mid-season ‘drain’ is practised, a reduction in water use of about 50 mm (0.5 ML/ha) could be expected. Results from this project and from project 1204(A) indicate that where water use is the total water balance ie. includes rainfall and change of storage in the soil profile, water use efficiency from a fully ponded crop is unlikely to exceed 7.5 kg/ha/mm (0.75 t/ML).

Modeling Irrigated Cropping systems with Special Attention to Rice Wheat Sequences and Rice Bed Planting

Thu, 20 Oct 2005 00:00:00 GMT

Modeling Irrigated Cropping systems with Special Attention to Rice Wheat Sequences and Rice Bed Planting Humphreys, E (ed); Timsina, J (ed) The rice-wheat cropping systems of the Indo-Gangetic Plains (IGP) are of immense importance for food security for south Asia. Over the past 40 years the increase in rice and wheat production has kept pace with population growth due to improved varieties, increased inputs, especially fertilisers, and the expansion of irrigation. However yield stagnation, and possibly yield decline, water scarcity, and water and air pollution are major threats to the sustainability of rice-wheat systems and food security. Therefore the design and implementation of alternative production systems with increased resource use efficiency (especially water) and productivity and reduced adverse environmental impact are urgently required. Bed farming, practised for several decades for crops other than rice in Australia, Mexico and elsewhere, was introduced to the rice-wheat regions of the IGP in the mid 1990s. Farmer experience and research have shown that bed farming offers significant advantages for productivity and resource use efficiency for wheat and other non-rice crops. More recently, attention has focused on the possibility of also growing rice on beds in the IGP and Australia, with the associated potential benefits of permanent bed systems including reduced land preparation costs and turn around times, increased cropping flexibility, and increased productivity of “upland” crops grown in rotation with rice due to improved drainage and soil structure and improved rotations. The radical shift from ponded rice culture on the flat (with or without puddling and transplanting) to intermittently flooded bed layouts affects a host of interacting factors influencing productivity and resource use efficiency of both rice and crops grown in rotation with rice. These factors range from weeds to nutrient availability to pests and diseases to water dynamics to stubble management options. The potential benefits and disadvantages of permanent bed systems need to be quantified under a range of agroecological conditions, and optimum layouts and management systems need to be identified to maximise potential gains. The Australian Centre for International Agricultural Research (ACIAR) is funding a major new project LWR2/2000/89 Permanent beds for rice-wheat and alternative cropping systems in north west India and south east Australia. This is a collaborative project between Punjab Agricultural University, CSIRO Land and Water and NSW Agriculture, with additional support from the International Atomic Energy Agency (IAEA/FAO) for the work in India, and additional support for the work in Australia from the Rural Industries Research and Development Corporation (RIRDC) Rice program, the Grains Research and Development Corporation (GRDC) and Coleambally Irrigation Cooperative Ltd and Murray Irrigation Ltd. The major part of the project comprises field comparison of permanent bed and traditional layouts for rice-based cropping systems in Punjab, India and NSW, Australia, with detailed monitoring, in particular focusing on crop growth and development, water and nitrogen dynamics and balances, and options for stubble management. The project also seeks to further develop and refine models for rice-wheat and alternative systems, and apply them to evaluate permanent bed and traditional layouts for a range of agroecological environments, and to identify options for maximizing resource use efficiency and productivity of rice-wheat cropping systems in India, and rice-based cropping systems in Australia. Therefore an early activity in the project vi was a workshop bringing together a small group of international scientists leading in the development and application of crop models including the modelling of crop sequences and twodimensional approaches. The objectives of the workshop were: 1. to review the state of the art in the modelling irrigated cropping systems (crop sequences as opposed to single crops) and bed geometries (as opposed to “flat” layouts) 2. to workshop conceptualizations of the ways forward in modelling crop sequences and bed layouts, and with particular attention to rice-wheat systems 3. to establish a network of contacts working in these areas to share progress and problems in the future.

Surface-Groundwater Iteraction Model of the Murrumbidgee Irrigation Area (Development of the Hydrogeological Databases)

Thu, 01 Aug 2002 00:00:00 GMT

Surface-Groundwater Iteraction Model of the Murrumbidgee Irrigation Area (Development of the Hydrogeological Databases) Khan, Shahbaz; Best, L; Wang, B This brief discussion paper documents key points arising from the Overseas Visit (24-28 June 2002) to the Institut National de la Recherche Agronomique (INRA) Joint Research Unit – Innovation in Montpellier, France1. The purpose of the visit was to: 1. Investigate the relevance of INRA agricultural extension practice to CRC Rice Project 5204; 2. Explore the potential for INRA – CRC Rice collaboration in agricultural extension. Key points arising from the visit are as follows: 1. Elements common to the French and Australian contexts of agricultural extension and rice production were identified during the course of the visit; 2. Social theory central to the research framework of CRC Rice Project 5204 was recognised as critically informing INRA agricultural extension practice; 3. INRA require an authoritative statement of CRC Rice intent in agricultural extension if the opportunity for collaboration is to be further developed.

A GIS Approach to Quantify Impact of Flooding on Shallow Groundwater Levels in the Wakool Irrigation District - Final Draft

Wed, 19 Oct 2005 00:00:00 GMT

A GIS Approach to Quantify Impact of Flooding on Shallow Groundwater Levels in the Wakool Irrigation District - Final Draft Wang, Butian; Khan, Shahbaz; O'Connell, Natalie Environmental degradation associated with shallow saline watertables is a major threat to the sustainability of agricultural industry throughout the Murray-Darling Basin. Located in the western part of the Murray Valley of NSW, the Wakool Irrigation District has experienced a history of water table rise, including likely contribut ions from widespread flooding. The community is interested in scientific evidence quantifying the impact of flooding on the shallow groundwater, in order to target management actions to control water table rise and salinity in this area. This study estimates the spatial and temporal impact of flooding on shallow groundwater for the Wakool Irrigation District through an extensive GIS analysis based on a large amount of piezometric data monitored over many years. By compiling the piezometric data into a GIS database and analyzing the data in a GIS application, we are able to quantify the net recharge caused by flooding and to visualize the spatial extent of the impact of flooding on the shallow water table reflected by water table change. The results show that flooding has a significant impact on the shallow groundwater. The floods during the record wet period of 1973-75 caused a net recharge of around 116x103 ML (0.52ML/ha in average) at the stage when water table rise reached its maximum value around December 1975. Apart from the magnitude of flooding, the amount of the net recharge caused by a single flood event is also related to the initial water table before the flood, which affects the shallow groundwater storage capacity. The higher the initial water table is, the less the shallow groundwater storage capacity will be, and consequently there will be less room for the net recharge, as shown during the 1973-75 floods. More frequent flooding such as the one experienced in 1981, whose recurrence interval is estimated as around 1 in 10 years, could result in 42.68x103 ML or an average of 0.19ML/ha net recharge at the stage around maximum water table mound, given the initial average water table depth being at 4.28m. There are strong connections between the local rainfall, flood, and water table change, suggesting that the floods happened in this area are normally due to both upstream and local rainfall. The major flood recharge areas within the Wakool area are mainly located along the Edward – Niemur River system. The groundwater recession following a flooding is affected by a number of factors, such as the initial water table depth, the climate conditions, the management actions, and etc.