Water allocation and access arrangements affect the livelihoods and well-being of a diverse range of water users, including irrigators and the environment increasing pressures on surface and groundwater resources have seen a shift in water management towards decision Processes that attempt to represent the interests of these diverse groups. Decision makers are increasingly being asked to take account of trade-offs between different users of water so as to make fair, equitable and/or efficient decisions that achieve a balance of social, economic and environmental outcomes.

In NSW, changes to water allocations and access through the design and implementation of Water Sharing Plans, involved negotiation between stakeholders representing many different interests and concerns. A key gap identified by many stakeholders involved in these negotiations was open access to integrated, scientifically sound and generally agreed upon information on the socioeconomic trade-offs likely to result from changes in access, allocation ~d pricing. In addition, estimates of impacts on the flow regime and on river health are also required. The Water Allocation Decision Support System (WAdss) has been

Developed and applied to two NSW catchments the Namoi and Gwydir River catchments for considering the trade-offs between environmental and socioeconomic outcomes resulting from changes in water allocation, access and pricing in the unregulated and regulated surface water systems and the groundwater system of these catchments.

The WAdss has been developed to be used in a workshop situation, allowing for analysis of a library of pre-run scenarios, sharing of scenarios between users, and creation of new scenarios live in meetings and workshops. I t also allows for reports to be generated which can be accessed from outside the system. The system has been tested in workshops situations with a broad range of potential users and found to have potential for considering water allocation issues.

Development of the WAdss has involved substantial stakeholder involvement. This has been aimed at giving stakeholders a greater sense of ownership of the models, results and WAdss, by incorporating their comments and ideas into the system. It was also important for obtaining information and data necessary for ground-truthing or calibrating the models in the system and for increasing the awareness of stakeholder groups of the existence of WAdss, its potential uses and limitations.

Overall the development process of the WAdss has been successful, given the maintained engagement of stakeholders in its development and support for its continued use and development. Initial development of the WAdss is complete. The WAdss is now moving into an adoption, extension and reapplication phase. Success in this phase will depend on the maintained engagement of stakeholders and the enthusiasm and input of researchers or other champions within Agencies or Catchment Management Authorities. With this support and adoption of the system by these groups for policy and planning processes it is hoped that the WAdss will lead to greater communication between irrigators and catchment management authorities and the development of policy options that lead to improved environmental outcomes at the least cost to production. The WAdss provides an important opportunity to

incorporate the opinions and knowledge of irrigators in the water allocation decision making process and debate. The potential of WAdss for use in other catchments and for incorporating the investigation of other issues (wetland ecology, salinity, vegetation change) is very high. WAdss has the framework and the analytic tools to examine trade-offs in these cases.

This travel Scholarship supported Dr Robert Mensah, who was invited by the International Cotton Advisory Committee (ICAC)and presented the topic “IPM is Key to Insecticide Management: Alternative Solutions for Insecticide Management in Cotton Crops” to the ICAC 77th Plenary Meeting on 6 December 2018. Dr Mensah’s presentation highlighted to the participants that over-reliance of synthetic insecticides to manage cotton pests worldwide has resulted in insecticide resistance, disruption of beneficial insect species, higher production costs and significant negative environmental impacts. Cotton industries worldwide require the development and adoption of alternative strategies and solutions for managing and controlling pests on cotton and other crops. Dr Mensah stressed that, although transgenic (Bt) cotton crops may be providing effective control for Helicoverpa spp., the development of sucking pest insect resistance to these crops remains a big threat.Attended and presented a paper at the 77th Plenary Meeting of the International Cotton Advisory Committee (ICAC). The theme for the event was “Cotton Challenges: Smart and sustainable solutions”. The meeting was attended by 385 persons including 20 member governments, six International organizations and 15 non-member governments. The agenda of the meeting included six open sessions (including “World Café” interactive session), six breakout sessions and two plenary sessions. The meeting discussed World Cotton Production, future cotton textile demand, governments support to the world cotton sector, combating effects of Climate Change on cotton, mechanization, drones and robotics for small scale cotton farms, combating pest resistance to biotech cotton and pesticides, Biotechnology, Cotton by-products and Inter-governmental policies on cotton seed exchange.

UNE1601 came about from a merger of two proposals. One proposed to develop a more detailed understanding of C under cotton, whilst the other focused on the potential for rotations to modify the soil microbial biology. To address the combined goals of the project, work was undertaken at ACRI on the long term rotational trial managed by Dr Guna Nachimuthu and broken down into three areas of investigation. These were; (i) Mechanisms of whole-profile C and N cycling, (ii) Microbial processes in the soil profile, and (iii) Below ground agronomy and constraints to plant growth.

Addressing the ‘Mechanisms of whole-profile C and N cycling’ became the focus for Dr Yui Osania. Her research in this area establishing that the maize rotation increased SOC stock in a Min Till/CW system. The mechanism for this was likely to be vertical movement of C in the form of DOC and that a strong correlation between SOC and soil N was evident, which indicated that C and N dynamics are interlinked. The conclusions from this were that agricultural management impacted SOC storage differently between the topsoil and the subsoil and that future research should explore the movement of C in the soil (i.e. leaching, root exudates), and the role of DOC in C stabilisation via microbial interactions or mineral interactions throughout the soil profile.

‘Microbial processes in the soil profile’ became the area of focus for Katherine Polain’s PhD candidature. Katherine’s work looked at both short and long term influence of the cotton rotaion under minimum tillage and found that microbial diversity was not influenced by rotational changes, which implied that there may be greater resistance and resilience in the system than previously presumed. Katherine’s work also highlighted that whilst the microbial biomass may be higher in the top 30 cm of the profile the activity can be as high in the 30-100 cm sub-soil of the cotton system profile as it is in the top. The implications from these observations are that we may need to look deeper in our systems if we want to truly understand the nutritional cycles that feed our plants nutrient demand and that might limit the losses of C from our soils.

The final aspect of the project was the ‘Below ground agronomy and constraints to plant growth’, which initially had to become more aligned to other projects when the appointed candidate had to withdraw and could not be replaced. Oliver, Brendan, Katherine, Guna, Brian and Yui did their best to address this aspect of the project. The associated work showed that ~25% of cotton fields are affected by sub-soil constraint, whilst the work at ACRI clearly established that furrow traffic led to soil compaction and with this a loss in microbial activity. Field vehicular traffic remains a necessity of our production systems, but the work done here adds to the number of proponents pushing for farms not only to move to minimum tillage, but controlled traffic farming systems.

This project was undertaken to investigate how dryland cotton production and its place in the farming system could be improved, particularly with the release of Bollgard® 3 varieties. Changes to the Resistance Management Plan (RMP) for Bollgard 3 with the relaxation of planting windows and pupae busting requirements offer the potential for greater flexibility in how growers might utilise cotton within the dryland farming system.

The project commenced with a series of workshops to engage with dryland cotton growers from across the northern region to better understand the strengths and limitations of the overall farming system and dryland cotton’s place within it for the purpose of identifying opportunities for where RD&E could have the greatest impact. The topics, concerns and opportunities raised at the workshops were then subject to a broad-based review to determine where RD&E could best be targeted for the betterment of the dryland cotton industry. The review identified a number of R&D gaps around the:

• implications for changes to pupae busting on the farming system

• need to develop effective zero-tillage crop destruction tactics

• opportunity to combine modelling with farming systems research to answer some of the more difficult crop sequencing questions raised by growers

• need to ensure that weed management practices extend across the system and are not carried out in isolation within each commodity

• potential to better extend a large body of existing R&D together with local validation to answer the many questions that growers have in expanding dryland cotton regions (e.g. the Liverpool Plains).

The grower workshops and review identified that it was regions with more marginal dryland cotton production prospects (lower rainfall and/or duplex soils) or areas where dryland cotton has been recently expanding (Liverpool Plains) that would potentially see the greatest benefits from new RD or E.

At the same time that the review was undertaken, a number of pilot studies were also conducted to examine the potential to overcome marginal soil moisture conditions with water injection and to test the use of the ultra-high pressure water jet cutting technology AquaTill for end of season crop destruction. Water injection both alone and with the addition of the moisture attractant SE14 (Sacoa Pty Ltd) was found to have limited potential to aid crop establishment under marginal soil moisture conditions. The use of AquaTill for the delivery of herbicide to post harvest stub cotton showed promise as a zero tillage crop destruction technique. This technique will be further developed by the Dryland Cotton Research Association in cooperation with the South Australian No Tillage Farming Association.

A conclusion of this project was the region spanning the border at Goondiwindi to Rowena and east to Quirindi in NSW represented some of the areas that would most benefit from targeted RD&E. The Queensland-based Department of Agriculture as the lead agency was not ideally placed to deliver on the identified needs of this region and therefore the project was concluded after the completion of the review so that a localised delivery model could be developed.

Farming systems in cotton are changing and weed management is again becoming more complex. The rise of herbicide resistance, particularly to glyphosate and the imminent introduction of new herbicide tolerant traits to dicamba and glufosinate has changed the way weeds need to be managed. The project team undertook to pre-empt these changes.

Three new modelling and decision support products were created for industry. The BYGUM decision support tool predicts economic outcomes from summer grass weed management strategies. The tool can be used to create and compare five-year rotations of cotton, grains and fallows, including cover crops, demonstrating the effectiveness, cost and efficiency of herbicide and non-herbicide weed control. BYGUM has been used in workshops and to create extension materials, and has been downloaded by over 300 unique users to date. The Weeds of Australian Cotton ID app allows identification of 50 key weed species in cotton fields. The app uses the Lucid framework and an extensive image library. The app is among the first to include cotyledon shape as a factor for identification, meaning weeds can be identified while still small enough to control effectively. It is free to use and available in Apple and Google app stores for use offline, and via the Identic Lucid Key library for use on desktop and laptop computers.

The Diversity model is a world-first multi-herbicide, multi-species, polygenetic model of herbicide resistance evolution. It determines and quantifies how much diversity is enough, to slow or prevent evolution towards resistance. We used the model to assess the resistance potential of weed management under new triple stack systems, such as Xtendflex® cotton. Our results suggest three key points:

1. That these systems are substantially more diverse than Roundup Ready, and with the right extra tactics can be the basis of long-term effective weed management;

2. Glyphosate, glufosinate and dicamba alone or with minimal extra modes of action are incapable of controlling our existing glyphosate resistant grasses and fleabane—systems are likely to fail due to poorly controlled resistant populations long before new resistances have time to develop;

3. The 2+2+0 strategy is predicted to remain effective, but modelling multiple species at once reminds us that both grasses and broadleaves need multiple effective options in the system.

Genetic exploration of the mechanisms of glyphosate resistance in key weed species led to the discovery of the key role of ploidy and gene copy number in the evolution of glyphosate resistance. Our work on gene expression in fleabane and the genome assembly showed that there are many copies of the target site EPSPS gene in this species. This makes it very hard for fleabane to evolve target site resistance to glyphosate because many copies have to have a mutation, instead, species with many copies of the target site gene have to evolve non-targetsite resistance and this is more difficult for the weed because it usually involves more than one mutation. Feathertop Rhodes grass was found to be diploid with one copy of the EPSPS gene, and this species evolved resistance over 10 times by target site mutations. This understanding explains why it took sowthistle so long to develop resistance to glyphosate, and allows us to make predictions about herbicide resistance evolution in the future. Diploid species with one copy of the target site gene will be more likely to readily evolve resistance to a herbicide than polyploid species or those diploid species with multiple copies of the target site gene.

Work on the population genetics of four key species led to some surprising results. Fleabane is considered a well-dispersed species, but had strong regional genetic structure indicating that wind dispersal may play less of a role than previously expected. Windmill grass and feathertop Rhodes showed very little evidence for outcrossing, but there may have been some admixture in the past. Outcrossing is important because it affects the ability of a weed to develop resistance to multiple modes of action (MOA). Fleabane and sowthistle had evidence for some outcrossing in the genetic data, but we were unable to find experimental evidence for outcrossing in 200 offspring of each species. This highlights how very low levels of outcrossing might still play an important role in the evolution of resistance in species like fleabane that we had previously thought to be only self-pollinating.

In windmill grass and feathertop Rhodes grass, their highly selfing reproductive mode can be used in the fight against herbicide resistance. These species are less able to ‘stack’ resistance to different modes of action.. Our work shows, however, that feathertop has evolved resistance multiple times and how these have spread across the cotton system, and that almost 1/3 of windmill grass populations are now resistant. Each glyphosate resistant individual has the potential to evolve resistance to a second MOA. and our work highlights the importance of controlling glyphosate resistant populations to avoid multiple MOA resistance. Overall, the population genetics work emphasises the importance of the ‘0’ in the 2+2+0 strategy survivor control is essential to prevent the spread of resistance and to avoid multiple MOA resistance.

Studies on the growth and development of awnless barnyard grass, feathertop Rhodes grass, windmill grass, fleabane and sowthistle were conducted. In general, with the summer grasses, plants that emerged at the start of summer grew larger and produced more seed than those emerging later. This is where the focus of control should be for the greatest impact. However, it is important to note that plants emerging later still produce seed and need to be controlled. Sowthistle now has the ability to emerge and grow well throughout the year. Fleabane also appears to be adapting to warmer temperatures, readily producing seed throughout spring, summer and autumn.

The addition of glufosinate and dicamba has the potential to improve control, particularly on the five key species tested. When glufosinate was used, as a double knock partner, effective control was achieved in both glyphosate-resistant and susceptible populations tested. The glufosinate double knock should prove an effective option in Xtendflex® cotton.

Research on cover crops was hampered with dry conditions, and as the result the effects on weed emergence were limited. However, growers have shown cover crops to be an effective option provided they start with a clean crop and ensure that the cover provided is adequate and evenly spread.

The 2+2 and 0 was shown to be an effective management strategy for long-term resistance management. Research also concluded that additional options will provide more effective control in years with more rainfall events and subsequent emergences.

This project aimed to provide ecological information on an important pest species to underpin strategies for resistance management in Bt cotton. The cotton industry relies on Bt, now in Bollgard III® varieties, which provide security to growers, enable new farming systems and reduce pesticide use, ensuring continued social license to farm. At the time the project began, these benefits were threatened by rising frequencies of alleles giving resistance to Bt, especially to the Cry2Ab toxin in H. punctigera. Current resistance management plans were designed for H. armigera, but now they also had to consider H. punctigera. Updating our understanding of H. punctigera was therefore crucial. We needed to revisit key questions such as immigration from the remote inland, which was previously thought to be extensive and a valuable asset for resistance management, because it brought genes from unselected populations into cropping areas, thus diluting resistance.

For the previous three years, we had studied the ecology of H. punctigera in western Queensland, and compared results to the work we and others did in the 1980s and 90s. We had found that many remote inland areas still regularly produced many H. punctigera, but there was evidence of decreasing immigration to cropping areas. We speculated that the Millennium Drought of 2001 -2009 may have changed the distribution and abundance of key host plants, especially in mulga regions of western Queensland which act as a bridge to enable migration from the floodplains and sandy deserts of central Australia to cropping regions. However, in such a variable environment as inland Australia, we needed more data. This project aimed to provide better understanding of long term changes in H. punctigera populations that might affect pest impacts on cotton and other crops, and management of resistance to Bt in cotton.

We established ten pheromone trapping sites, six in western Queensland and four in non-cropping regions of South Australia, to monitor moth populations. Results showed fewer moths than before the Millennium Drought in parts of western Queensland, but substantial numbers in some South Australian sites, suggesting alternative migration routes from the inland. Eleven survey trips were made to inland regions, during which larval populations were sampled by sweep netting, and vegetation conditions and the presence of host plants were recorded. These results indicated a depletion of good host plants in the mulga regions since the drought, which probably contributed to reduced migration. We also studied diapause induction and termination and the timing of spring emergence in inland populations, and the potential for host plants with the C4 photosynthetic pathway to contribute to inland populations.

We added results from this project to data from earlier projects in a geographic information system which provides a long-term record that is unique in the study of insect pest ecology in Australia. The information will be crucial for the development of pest forecasting systems for a range of crops affected by H. punctigera. For cotton it has provided a long-term perspective of changes in resistance to Bt which indicates that increases in the frequency of resistance alleles in H. punctigera may occur from time to time due to prolonged droughts. However such increases are unlikely to be sustained, and the greatest resistance risk continues to be posed by Helicoverpa armigera rather than H. punctigera, because this species does not develop large populations in the inland.

Development of a land use indicator set for the Australian cotton industry to demonstrate the sustainability impacts on soil health:

May we recommend that the follow criteria be considered when developing an indicator set for the Australian cotton industry:

General:

• Land use will probably be one of a number of environmental impact categories being assessed by an LCA practitioner as part of a sustainability assessment, each with their respective metrics, and therefore the number of land use metrics need to be practical and manageable from this perspective

• Apart from meeting specific industry requirements, the cotton industry should also use this framework and initiative to communicate its own sustainability achievements as part of regular reporting.

• Through this initiative, the Australian cotton industry should aim to stay at the forefront in this space

• This is a new sustainability space and industry is only applying a single indicator / metric for land use at present. The Australian cotton industry may therefore be afforded the leniency of adopting a conservative and phased approach whereby a limited and suitable number of indicators are implemented at first, with the intention of increasing this as practical data structures become available or put in place.

• Importantly the programme should be of direct benefit to growers to address their concerns about the state of the soil that they will be passing on the next generations

Therefore, specific recommendations:

1) Use 2 sources of data: firstly grower surveys to assess land use intensity and input intensity, and secondly soil test data for another 6 metric outcomes

2) Indicators from soil tests: soil organic carbon, ph., phosphorous, potassium, nitrogen (total, nitrates and ammonia), CEC and % sodium.

3) Soil compaction is a major concern for growers and therefore an additional ‘wet sieving’ test will give an indication of soil structure and stability – it appears that Nutrient Advantage is not able to do this but EAL Laboratory can for $60, and separate samples will have to be sent there but it is probably justified.

4) All results received form Nutrient Advantage lab and therefore provides a common methodology and able to utilise historical grower data for the database and trending – growers that we have consulted is agreeable to this.

5) Form the “soil sustainability awareness group’ SSAG with a pilot group of concerned growers to ‘test’ the programme to assess how it could be rolled out on a regional and national scale.

6) Growers are required to take soil test at those specific sites including a ‘native’ sample each year, according to a standardised procedure.

7) Results will be expressed as a % relative to the native soil, which can be benchmarked, aggregated as a single farm score, and scaled / aggregated to a regional and national level accordingly.

8) Results will be treated anonymously although will receive their specific results evaluations, along with their normal results via their agronomist / consultant.

9) CRDC / Cotton Australia or a funded project may have to cover the costs of the additional native soil test, the wet sieving test and potentially the assessments.

It is unfortunate that the above indicators will not assess soil biology / microbial life, but this is an expensive, time consuming procedure. Fortunately soil carbon is a strong driver of soil biology, and perhaps a suitable proxy indicator could be introduced for this in the future.

We have had discussions with a number of growers, who have been very supportive of the idea, and keen to join such an initiative and are willing to provide their historical soil test data. We have also consulted with relevant scientists for their views and recommendations which have been taken into consideration.

A weed control threshold for cotton production was first released to the Australian industry in 2008. It has been widely used as a guide to the level of weed pressure that can be tolerated in fields without economic damage occurring. However, the model behind the threshold was based on a limited data set, derived using the ‘mimic weeds’ (common sunflower, mungbeans and Japanese millet), based on the assumption that the level of competition from these ‘mimic weeds’ could be readily related to real competition levels from real weeds.

Project DAN1601 focused on testing the underlying assumption that the competition results from mimic weeds could be related to real weeds, and, assuming the approach was valid, using a much larger data set to derive a more accurate threshold.

Data from 3 years was used to test the validity of using mimic weeds to define competition in irrigated cotton. Competition levels were compared between differing population densities of: fierce thornapple vs. common sunflower; bladder ketmia vs. mungbean; and, awnless barnyard grass vs. Japanese millet. Many similarities and differences were found between the mimic and real weeds, but an underlying relationship was derived that showed that as far as the cotton was concerned, the only real differences between the six ‘weeds’ were related to weed height and biomass – in other words, bigger weeds are more competitive! So, competition experiments using mimic weeds are valid, and a lot easier to conduct than experiments using real weeds. Also, the findings of this work showed that it is possible to extrapolate the results from a few mimic weeds to a wide range of real weeds.

Based on this finding, data from field experiments between 2002 and 2015 was collated and analysed to develop much more accurate relationships between the three mimic weeds weeds’ (common sunflower, mungbeans and Japanese millet) and irrigated cotton. Three papers were developed, one for each weed type, developing dynamic weed control thresholds for these weed types. The first of these papers has been accepted for publication and the second paper has been submitted to the publishing journal. The final paper will be submitted when the third paper is accepted.

Results from the first paper showed that for a large weed (eg. fierce thornapple, Noogoora burr, sesbania), densities of 1 per m of row caused more than 5% yield loss if present in the crop between 43 and 615 GDD. Higher densities caused higher levels of damage. Where the weed can be controlled with glyphosate, a 1% yield loss threshold is more realistic, extending the critical period for weed control for 1 weed per m row to between planting and 836 GDD.

It is hoped that the next two scientific papers will be accepted for publication later this year, and then the results from the work can be extended to the Australian industry, giving growers a firm threshold for controlling weeds in irrigated cotton.

In addition to this core work, the project has continued to support the cotton industry through articles, meeting and input into the weeds sub-committee of the TIMS panel, as well as in other areas.

Work on a pupae busting experiment has continued, preliminary results indicating that pupae busting does deliver additional benefits through improved weed control.

A study into 2,4-D damage, prompted by the heavy damage experienced in the Walgett area in the 2017/18 season, highlighted the very low levels of 2,4-D that could cause damage to cotton. A series of tissue tests determined that damage at ACRI observed in this same season was caused by 2,4-D concentrations below the level of detection by instruments.

At the request of the CottonInfo team, all main articles in WEEDpak have been updated, and short (4-page) CottonInfo sheets developed from the longer articles.

This project has also had a large input, as lead, of a parallel project, DAN1805, the “Biological control and taxonomic advancement for management in the Noogoora burr complex”, which also finished in June 2019. The project involved a number of different facets and was exceptionally successful in achieving its objectives in spite of many issues. A final report on this project has separately been submitted to CRDC. Outcomes included: re-evaluating the taxonomy and distribution of the Noogoora burr complex, showing that based on genetics, there appears to be only two groups of burrs (species), with many hybrids occurring; successfully developing a bioherbicide which is effective across all the Noogoora burr species; and determining that all plants in the Noogoora burr complex are hosts of the Verticillium wilt pathogen, with multiple defoliating and non-defoliating strains of the pathogen isolated from the burrs, often with more than one strain present in a single burr. Four scientific papers are currently being developed from this project.

Following the success of the technology developed around the bioherbicide for Noogoora burr, steps towards commercialisation of a bioherbicide for Bathurst burr have been commenced.

The AgFutures – Innovation and Investment Conference was held on the 22-23 November 2016 at the Brisbane Convention and Exhibition Centre. AgFutures was the first Queensland conference focusing on future technology in agriculture and agricultural investment opportunities. Internationally-renowned researchers and innovators demonstrated the latest agri-tech developments and applications, including digital and data platforms, robotics, satellites, and bio-technologies.

Experts from the business and investment community also discussed emerging trends, business opportunities and capital models from the farm gate to agribusiness, agri-tech, processing and research.

As part of the conference, the Peter Kenny Medal and Minister’s Emerging Leaders Award were presented at the AgFutures Conference Dinner.