Improving the efficiency of water use in agriculture is increasingly essential to maintain the

profitability and sustainability of farms. This involves applying only the minimum necessary

irrigation water to maintain or improve the yield of individual plants. Irrigation control strategies can

be used to improve site-specific irrigation. These control strategies generally require weather, plant

and/or soil data to determine irrigation volumes and/or timing that improve crop water use efficiency

while maintaining or improving crop yield. As the plant response and environmental conditions

fluctuate throughout the season, control strategies which accommodate temporal and spatial

vanability in the field and which locally modify the control actions (irrigation amounts) need to be

'adaptive'. Such irrigation control systems may then be implemented on large mobile irrigation

machine, both 'lateral move' and 'centre pivot' configurations, to provide automatic machine

operation

A simulation framework 'VANwise' has been created to aid the development, evaluation and

management of spatialIy and temporalIy varied site-specific irrigation control strategies. The cotton

model OZCOT has been integrated into VANwise to provide feedback data in the control strategy

simulations. VANwise can accommodate sub-field scale variations in allinput parameters using a

one square metre cell size, and permits application of differing control strategies within the field, as

well as differing irrigation amounts down to this scale. An automatic model calibration procedure

was also developed for VARlwise to enable real-time input of field data into the framework. The

model calibration procedure was accurately implemented with measured field data and the calibrated

model was then used to evaluate the effect of using different data inputs in an irrigation control

system.

A key challenge for the Australian cotton industry is to ensure that its’ reputation for high quality is maintained and year to year variation in yield is minimised. There is also continued pressure to explore changes in agronomic practice to deal with rising costs, reduced terms of trade, need for improved use efficiencies for crop inputs, and in response to technological changes such as new varieties, plant hormones, and precision agriculture innovations.

To maintain progress, research is needed to update existing agronomic recommendations as well as identify new practices or tools that increase yield and provide resilience to crop stress in both irrigated and dryland systems. There have been advances made in growth hormone and regulant compounds that could assist in managing stresses (water and heat) in cotton. Past research has demonstrated the utility of some of these hormones, but this was done in lower yielding crops in the USA where their use was often not economically viable. Recent successful research in Australia using an ethylene inhibitor on waterlogged cotton to reduce fruit shedding has highlighted that the use of hormones should be reconsidered for both managing stress and assisting with novel approaches to agronomic management to improve resilience and profit.

This project addressed the following research objectives (i) investigate whether the use of novel agronomic approaches utilising various plant hormones could raise yield and build crop resilience to stress, raising profit in both irrigated and dryland systems; (ii) assess an alternative approach to day degree that delivers more precise predictions and assessments of crop development for all cotton regions that will facilitate more accurate growth assessment and management decisions; and (iii) Maintain build crucial independent research capacity in cotton agronomic research through the support of Claire Welsh’s PhD studies in rainfed cotton systems.

Growth regulator/hormone research - Over the course of the four years many experiments were conducted to evaluate key research questions. This was a challenging project where experiments were compromised by hail (1 on-farm experiment in 15/16 season, and most experiments at ACRI in 2018/19 season), extreme cold then extreme heat and disease (verticillium) (all ACRI experiments in the 2016/17 season), waterlogging when not required (1 on-farm experiment in 17/18 season), and extreme rainfall events removing lint from the plant (2 on-farm experiments in Emerald in 2016/17).

Research addressed the following key questions:

• Can yield and quality be improved on fully irrigated crops using consecutive applications of anti-ethylene agents?

• Can various combinations of anti-ethylene agents reduce the effects of mild stress in irrigated cotton?

• Can anti-ethylene agents improve yield and quality by retaining fruit at cutout using anti-ethylene agents?

• Can the use of anti-ethylene agents help with yield reduction associated with a skipped irrigation?

• Can a combination of anti-ethylene agents and foliar fertiliser reduce the impacts of a waterlogging event? This was the first research conducted where they will be assessed in combination.

The conditions in which this project was undertaken was challenging with the climate extremes experienced. Variability within many experiments was far greater than effects caused by the treatments making it difficult to discern any consistent treatment effects.

It was hoped based on the waterlogging experiments conducted in the past that rates and timings would have led to differences. These results potentially highlight that unless there is a severe stress imposed (like a waterlogging event) to prevent significant fruit loss there may be little utility in retaining fruit in less stressful situations. Lack of differences could simply be a result of cotton’s ability to compensate the loss of fruit to allow assimilates to support the growth of existing fruit (resulting in larger fruit; evidenced in this study). This is a known mechanism that cotton uses to overcome stress in milder situations. Overall at the present time, and given the current high cost of these hormones, the multiple application strategies that generated differences would be currently cost prohibitive. Future research should be conducted in more controlled conditions, with greater replication, and with an explicit ability to quantify the stressed conditions. Ability to utilise a technique that can quantify the ethylene hormone response would also aid this research. Therefore, at this time no clear recommendation of the use of these growth regulators to answer the questions addressed in this study can be made.

New Day Degree Calculator - Key management recommendations rely on accurate estimates of crop development and boll periods using the day degree approach. The day degree approach is a fundamental tool used to assess crop development against growth and management (eg nutrition sampling, first irrigation) milestones for that particular season’s climate. Currently, the ‘day degree’ approach is not robust to accommodate extremes of climate (heat/cold). There is a need to refine this approach to ensure the accuracy of this critical tool to accommodate temperature extremes and ensure we can use it confidently for management decisions in new cotton regions (eg. Griffith). New approaches will be developed to accommodate temperature extremes improving predictive capabilities and management recommendations that rely on this approach.

During the course of this project we have compiled data from multiple seasons where first square, first flower, and sometimes first open boll were recorded. Data was collated from both Australian and USA locations. We compared a number of approaches: 1. The existing industry day degree approach and targets; 2. A modified approach using the existing approach with a maximum temperature threshold and existing thresholds; 3. A published method used in the USA in Arizona; and 4. A method that uses an alternative approach calculating a rate of progress from data measured in the Canberra Phytoton previously published by Bange and Milroy (2001).

This study was able to demonstrate that there were improvements in the predictability of time of first square and first flower measured in cotton crops. Two functions were able to better predict these phenological stages compared to the existing function used currently in the Australian industry (Constable and Shaw, 1988). The best performing functions were a variable temperature day degree function that used a base temperature of 15.6 °C and an optimum of 32 °C, and a physiological rate function that reflected similar temperature characteristics as the variable function. The use of these functions should be considered in the development of new cotton crop predictive capabilities as they will be able to account for more temperature extremes (high and low, that maybe more prevalent in a changing climate) and where cotton production moves into new regions. The analyses of functions here also support the use of a base temperature of 15.6 °C (60 °F) used in USA cotton systems.

Michael Bange began promotion of the understanding relating to the use of these new functions throughout the industry. An industry you tube video was also developed on the use of day degree functions and included outcomes generated in this study. CSD have also implemented the new function as part of their online suite of agronomy tools

In 2017, the National Farmers’ Federation announced a vision for Australian agriculture to

exceed a farm gate value of $100 billion by 2030. AgriFutures Australia commissioned ACIL Allen to:

Establish a baseline projection which estimated a farm-gate value of $84.3 billion by 2030, $15.7 billion below the target.

Investigate what opportunities and

barriers impact agriculture’s ability to exceed the target and deliver enduring profitability.

Understanding the $100 billion vision

The $100 billion target was created to provide focus and establish national dialogue on how to grow the sector. The target is ambitious, requiring a growth rate of 3% annually, double the current trend. The target is directional for how Australia can increase productivity and better prices in the face of ongoing climate and market volatility. Success

is greater enduring and sustainable profitability rather than pursuing farm-gate value at any cost, or claiming credit from favourable conditions.

Progress toward the target requires alignment and execution of strategies that contribute to improved enduring profitability. The strategies need to be sufficiently flexible to facilitate adaptation across the industries that make up agriculture and over time as the need, and circumstances allow.

Drivers and risks on which strategies can be built

Four drivers and four risks have been identified based on nationwide consultation across industries and analysis. The drivers and risks were chosen on the basis they can provide an enduring platform on which strategies can be supported, built and implemented. They are adaptable and not exclusive.

Drivers

Technology and data – getting more from adoption

Off-farm R&D – creating value up the supply chain

Off-farm infrastructure –efficiency & capital attraction

Markets – accelerating access and development

Risks

Climate and water – adapting farming & infrastructure

Biosecurity – sharing responsibility to sustain integrity

Regulation – sustained reform for efficiency & integrity

Consumers – meeting/exceeding changing preference

Moving towards action

The report provides an approach for conceptualising the opportunities and risks, against the backdrop of uncertainty, facing agriculture. The approach presents a range of possible strategies/investments for delivering enduring profitability by the sector. For these strategies/ investments to be implementation ready’ it will be necessary:

• To address the immediate opportunities and risks with a targeted program of investments

• • For industry and government to co-invest in the design of strategies/investments that meet the requirements of each industry and agriculture as they emerge. These strategies/investments may not be

the same as those reccomended and could include

provide an enduring platform on which strategies can be supported, built and implemented. They are adaptable and not exclusive.

Risks

Climate and water – adapting farming & infrastructure Biosecurity – sharing responsibility to sustain integrity Regulation – sustained reform for efficiency & integrity Consumers – meeting/exceeding changing preference

industry-wide investments. If the risks become severe it is anticipated that the costs of developing these strategies/investments will be insignificant compared to the costs of implementing structural adjustment policies and industry support mechanisms that are either insufficient or overly engineered

• To build the institutional framework which will provide clarity for the roles and responsibilities of parties to the vision and to provide a platform for coordination, and investment.

• • To build the analytical and research capabilities of institutions required to monitor the economic, social and environmental costs and benefits associated with prosecuting the $100 billion vision.

Three species of Tetranychus spider mites are found in Australian cotton crops. Spider mites cause damage to cotton by feeding on individual leaf cells using their chelicerae to pierce and remove the cell contents. Tetranychus urticae (Koch) (two-spotted spider mite: TSM) has been extensively researched in cotton and can reduce photosynthetic capacity, stomatal conductance and ultimately lead to decreased yield and fibre quality in cotton. However, no research into the damage potential or ecology of Tetranychus ludeni (bean spider mite: BSM) and Tetranychus lambi (strawberry spider mite: SSM) has been conducted. This research aimed to compare the relative damage to cotton caused by each spider mite species and to investigate spider mite ecology in cotton.

Cultures of each mite species were established in a glasshouse. Glasshouse studies were performed to compare the damage caused by each species on potted cotton plants, using a leaf damage index (LDI). TSM caused twice the level of damage than BSM and three times the damage of SSM. By week five, 33% of leaves on plants infested with TSM had defoliated. No defoliation was observed for either BSM or SSM. In addition, the damage caused by SSM was never significantly different from control plants where mites were excluded.

Laboratory studies found that average development of BSM (12.3 days) and SSM (13.7 days) from egg to adult on leaf discs was significantly slower than TSM (11.39 days). However, there was no significant difference in the mean number of eggs laid per day for TSM (6.3 eggs) and BSM (5.3 eggs). The implications of life history traits and how the result might change at higher temperatures are discussed.

Competition between mite species on single potted cotton plants was investigated in two glasshouse experiments. After two weeks the total number of females and distribution on plants was compared for each species alone or in the presence of another species. Findings from the first experiment at 30.1 ± 4.5°C suggest TSM suppressed the BSM female population and displaced SSM females from individual nodes of the plant. The second experiment at 26 ± 1.1°C included an additional cotton cultivar containing Bollgard 3 traits. Significantly higher numbers of TSM females were recorded in each pairing with SSM compared with the number of females in SSM populations alone. This was an unexpected result as TSM is considered to be declining in incidence across cotton growing regions and suggests environmental factors are contributing to the changing mite species complex.

Field surveys were conducted in northern New South Wales to determine the distribution of SSM within the cotton canopy to assess the relevance of the current mite sampling protocol for this species. Surveys indicated that the current sampling protocol would be reliable for late season sampling as mite abundance was very similar throughout the cotton canopy. The survey also detected BSM for the first time in recent years in cotton and in the same fields as an established population of SSM.

The results of this study recommend modification of current practices in cotton mite management to ensure accurate identification of the species present. This may help avoid unnecessary insecticide applications for mite species that may never reach economically damaging levels. They also suggest that there are other factors in the cotton landscape contributing to the changing mite species complex. This research provides basic research to support the sustainable management of a changing mite complex in Australian cotton.

For further information, contact Chris Shafto.

Email: chris.shafto@dpi.nsw.gov.au

FluroSense crop analytics and decision support platform has been enhanced with work-ready nutrient mapping and recommendation workflows, accessible for cotton grower via data integrations with major farm management systems.

The nutrient recommendations combine the science from widely accepted in Australian cotton industry tool NutriLOGIC/CottAssist with remote sensing imagery and sampling data from grower’s won fields. The growers’ data is used for additional calibration of the nitrogen recommendation to achieve higher accuracy through model localisation. The workflows for generation of management zones, suggested sampling points and derivation of the machinery-ready shape file with nitrogen recommendations are near-real-time, and are highly automated providing growers with the timely, tailored decision support, that has not been available to date.

The evident benefits for the growers and advisors are in the easy of use, shorter turnaround for generation of recommendations and savings on inputs from early detection and crop stress mitigation.

The case studies with progressive Australian cotton growers and agronomists demonstrate the willingness of the industry to adopt science based decision support tools, such as FluroSense, and the benefit that can be achieved from variable rate input application and improved yield through more accurate timely management.

Research summary:

In the course of the study aerial and satellite image collection campaigns were conducted covering around 17.000 ha of cotton in the Narrabri/Moree area with revisits during the season. The multispectral and hyperspectral imagery collected in the study was utilised to map the nitrogen levels of cotton crop in periods of in-season nitrogen application and later to monitor the impact of the fertilisation strategy on yield. Correlations were established between the remote sensing imagery and the cotton canopy nitrogen content. Using the remote sensing estimate of canopy chlorophyll content index (CCCI), several management zones were defined in each of the research and commercial fields taking part in the study. The tissue sampling point selection was based on the management zones and was performed in a novel way that ensures robust results with minimal testing points.

The accuracy of the nitrogen map generated by the model has been defined through a correlation coefficient of R2= 0.81. The accuracy and the practicality of the method for automatic nitrogen map generation using an online software tool were validated for in-season nitrogen management to improve the Nitrogen Use Efficiency.

Main outcomes and industry benefits:

The developed research models linking remote sensing imagery and tissue sampling results have been incorporated into an online platform, FluroSense. The online platform is designed for crop management using remote sensing imagery, and incorporates the learnings from the trials in the form of the link between the remote sensing imagery and plant tissue sampling through the management zone definition, smart sampling and scouting tools, and ultimately crop canopy nitrogen map generation tool.

The FluroSense platform has been launched with the free trial access for cotton growers in recognition of the CRDC and grower community support.

The service consisting aerial and satellite imagery in combination with the online decision support platform are now offered to cotton growers in Australia. The service allows agronomists and growers to access the remote sensing imagery, the insights from the crop health analysis, guidance on ground-truthing the crop performance with tissue testing as well as tools for generation of the management zones and application maps for in-field use. Alongside the nitrogen management tools the platform allows the users to monitor the performance of their crops across the season and perform the analysis of the yield and electrical conductivity layers, which combined with the remote sensing imagery provide a comprehensive view of the field variability and the strategies for its potential improvement.

Contact details:

Anastasia Volkova

CEO, FluroSat

anastasia@flurosat.com

A capacity to accurately assess economically important insects and their impact on crop physiology is pivotal to making informed and cost-effective decisions within an Integrated Pest Management (IPM) framework. The use of transgenic cotton provides a strong platform for IPM in the management of Helicoverpa spp. However, sucking pests such as Creontiades dilutus (green mirid) and Nezara viridula (green vegetable bug) are not controlled by the Bt toxin produced by transgenic cotton. Traditional sampling techniques can underestimate abundance of green mirid and green vegetable bug populations in cropping areas because these pests are easily dispersed and their distribution is often not uniform in cotton fields. Therefore, there is an urgent need to develop an effective surveillance system to measure peak activity of these pests throughout the growing season and to provide a predictive tool for identifying quantitative shifts in population abundance that would optimise the timing of control measures.

The Zappa trap was previously tested in proof-of-concept trials over a three year period from 2015 to 2018. Results of these trials demonstrated the potential of the Zappa trap as a sentinel tool for providing growers with an early warning of pest presence, particularly green mirids and green vegetable bugs, which are otherwise difficult to quantify under field conditions. The Zappa trap could also have a direct pest management application as an “attract and kill” strategy, potentially offering growers an alternative method to reduce pest numbers while mitigating risk to non-target species and enhancing the IPM potential in cotton.

The aim of this one year project was to further test the potential of the Zappa trap in field trials located in different cotton growing regions and under intensive sampling regimes. The results provided additional evidence that Zappa trap sampling could be a useful biological indicator for predicting the timing of mirid nymph activity in cotton because temporal synchrony was consistently observed between adult mirids recorded from Zappa trap and total mirid numbers samples recorded during in-field insect checks. Notwithstanding the possibility that Zappa trap sampling could be confounded by environmental factors such as the speed and direction of prevailing winds, the information could nevertheless provide an early warning for the presence of populations in the vicinity of cotton fields and heighten grower awareness to the need for vigilant assessment of pest abundance to optimise the timing of spray applications.

The study of trap placement on the distribution of mirids within cotton indicated that mirid nymph abundance may be influenced by distance from the trap location. Results from the assessment of crop damage generally support the insect abundance and distribution data and there was a trend toward higher levels of insect damage to bolls and lower yield potential at increasing distances away from traps, suggesting that the placement of traps in strategic locations around cotton fields could have a positive influence on yield outcome.

The predictive capability of the Zappa trap could provide the opportunity to manage populations in a timely manner and minimise the damage to fruiting structures of plants while optimising the cost of effectively and sustainably managing green mirids and green vegetable bugs on cotton. An additional benefit could be an increased understanding by growers of pest phenology and behaviour of these problematic species which could reduce reliance on chemical control measures and reduce the risk of flaring end-of season-pests in cotton such as silver leaf whitefly.

This project has conducted a nation-wide survey to better understand Australian producers’ needs and issues in relation to agricultural data. The survey included multiple industries and regions, to increase the researchers understanding of the range of issues facing different kinds of Australian producers in relation to agricultural data and identify the key factors, attitudes and perceptions that are likely to influence levels and trends in adoption of digital technologies in Australia agriculture.

The objective of this survey was to enhance the understanding of effective data technology adoption pathways, which take into account producers’ needs, perceived risks and benefits, and expectations across a wide range of agricultural industries.

To achieve the goals of the research project, the survey was designed to collect data toward the following objectives:

• To benchmark the current state of agricultural data systems, which include telecommunication infrastructure, the types of data collected and how they were stored, and the software used to manage the data;

• To examine how producers perceive the usefulness of the data in supporting farm management, their concerns over the ownership and privacy of the data they have collected, and the potential uses of aggregated agricultural data; and

• To explore producers’ willingness to share various types of data with different actors, which include other farmers, agricultural industry-based organisations, technology and service provider businesses, research institutes, and the Australian Bureau of Statistics.

Background The project ‘Feasibility study of managed aquifer recharge [MAR] for improved water productivity for Australian cotton production’ is investigating the potential to implement MAR at a regional scale in key irrigated cotton growing regions of Australia. The first focus region was the Murrumbidgee River system, with particular focus on Coleambally Irrigation Area of Operations (CIAO). This case study aimed to evaluate whether MAR could be feasible for irrigated cotton production in the Murrumbidgee region, and if so, make recommendations on further work to evaluate local hydrogeological conditions, plan the necessary site-specific infrastructure, and establish the legal, social and organisational conditions for its implementation. The broad approach taken was to draw on evidence from a holistic feasibility assessment to scope the most promising opportunities (“scenarios”) for MAR, and to test and refine these scenarios with the local stakeholder working group.

Project aims: (i) to investigate the spatial and temporal patterns of Heliothis adult and larval abundance, mortality and host use by each species and their dispersal from other crops into cotton. (ii) to investigate the oviposition behaviour of Heliothis within