In 2012–13 NSW DPI undertook a nine month bench-marking project in both the western and southern NSW irrigation production region commissioned by the CRDC.

The aims of this project were for key NSW DPI agronomists to further develop technical skills in cotton growth and development and provide linkages to industry partners in the new production areas of NSW. CRDC required NSW DPI to add value to existing projects, build grower participation in both regions, provide economic insights and develop agronomic

management information for cotton industry extension services.

This project facilitated linkages to other projects focused on water use efficiency benchmarking (NSW DPI), cotton comparative analysis (Boyce Chartered Accountants) and growing day degree modelling (CSIRO).

NSW DPI facilitated data collection on six farm sites. Activities focused on collecting temperature and plant growth data to help validate day degree modelling for western NSW, collecting WUE data, agronomic management of crops, facilitating field days and meetings with growers and coordinating the development of future research, development and extension issues.

Four major RDE issues were prioritised by industry in March 2013. These were:

· nutrition (N, P and K) – when to apply, key growth stages, how to apply, quantities

· irrigation scheduling – the effect of pushing out irrigation at key growth stages

· back to back cotton – impact on yield

· genetics of heat tolerance.

This project was jointly funded through a QDAFF and CRDC partnership to provide a development and delivery extension program focused on national crop protection in cotton based farming systems, whilst also providing regional extension support within Central Queensland.

As part of the broader crop protection and biosecurity area within a farming system extension strategy, the project addressed targets relating to volunteer regrowth and farm hygiene practices. The extension strategy for these targets was focused on ensuring growers and agronomists were aware of the issues and were able to identify barriers to adoption, and to deliver training or identify research needs as appropriate. The extension strategy also involved strategic collaboration with research, particularly on crop protection issues, and included the communication of research to the wider industry as well as support to industry capacity building and communication

The project has been successful in delivering a campaign to increase awareness of the prevalence of volunteer cotton, as a significant threat to crop protection and biosecurity. The associated risks of volunteer cotton have been well integrated into various other pest, weed and disease messages, with recent survey data indicating that the majority of growers rate control of volunteers as either extremely or somewhat important. However, this increase in industry awareness has not yet translated into an on-ground change, with recent surveys demonstrating the presence of volunteer, ratoon and feral cotton to be unacceptably high throughout all cotton growing areas. Building on the work of this and other previous crop protection projects, it is strongly recommended that future research and extension is undertaken to refine volunteer cotton control tactics.

Water is essential for producing high yielding and high quality cotton and cotton is demanding in its water consumption requiring, on average, 5.2 ML/ha for peak production in Australia (Cotton Australia 2015). With the majority of the Australian cotton industry being water limited and changing climatic conditions indicating continued water scarcity, increased research into producing more cotton per unit of water has resulted. This approach is termed Water Use Efficiency (WUE) and is described by Howell (2000) as crop yield per unit of water use. Cotton crop yields would benefit from evaluation on bales produced per megalitre of water used, rather than on a per hectare basis (Roth et al. 2013).

In Australia water resource availability is highly variable due to the range of climates found across the country. The majority of Australia’s runoff (65%) is positioned in three drainage partitions located towards the far-north of the country, associated with tropical/sub-tropical climates. However, the majority of irrigated cotton (96%) is situated within the Murray Darling Basin (southern Queensland and New South Wales) which accounts for a mere 6.1% of national runoff (Murray Darling Basin Authority 2015). Hence, the majority of Australia’s irrigated cotton is concentrated where water resources are the most restricted (Chartres and Williams 2006; Roth et al. 2013).

Currently 16,660 GL of the 70,000 GL extracted in Australia is used in agriculture (Chartres and Williams 2006). In the 2011-12 season 14% (2231 GL) of this 16,660 GL was required to produce 4,240,000 bales (227 kg of lint per bale) of Australian cotton (Cotton Australia 2015). In general, the trend for Australian irrigated agricultural industries as a whole is increased water demand, highlighting that water availability is now the most limiting factor for not just cotton production (Chartres and Williams 2006; Roth et al. 2013), but agriculture in general.

Furthermore, irrigated agriculture will be integral to meeting demand if food production is to be doubled by 2050 (FAO 2009), as the challenge is to essentially produce more with less (Fraiture et al. 2007). The opportunity to grow crops close to their yield potential in areas which would otherwise be unable to, under rain fed conditions, is allowed for via irrigation. Hence, these crops primarily rely on irrigation water supply for optimal production (Howell 2000; Roth et al. 2013), meaning that in uncertain, or marginal, climatic conditions, minimising water losses is inextricably linked to production and profitability.

WUE involves the management of inputs and losses water. Inputs impact the volume of soil water contained within the profile (Roth et al. 2013). Characteristics such as porosity, bulk density and hydraulic conductivity affect a soils ability to hold water and a plant’s ability to access it (Radford et al. 2000). Inputs consist of irrigation and rainfall. Utilising rainfall reduces the irrigation requirement and improves irrigation efficiency (Cull et al. 1981). The effectiveness of these events is a function of soil infiltration and evaporative demand. Each cotton plant in a linear row has access to a certain volume of soil water in the row and inter-row space. The volume available is dependent on the row-spacing configuration. Wider row-spacings allow for greater access of soil moisture per plant (Roche et al. 2006). However, plant available soil moisture is limited by destructive management practices such as uncontrolled traffic (Chan et al. 2006).

The Australian cotton industry is currently considering a transition to 1.5 m row-spacing. The 1.5 m row benefits WUE, soil health and enterprise integration. Plants have access to larger volumes of soil water which increases utilisation of rainfall while reducing irrigations. Low plant densities per hectare would assist in reducing water input requirements (Enciso-Medina et al. 2002; Brodrick et al. 2012b). Current practice involves uncontrolled traffic in fields. This increases compaction and negatively impacts bulk density, mechanical impedance, porosity and hydraulic conductivity (Radford et al. 2000; Chan et al. 2006). The 1.5 m row-spacing enables Controlled Traffic Farming (CTF) where all machinery is driven on the same 3 m wheel tracks. Compaction is minimised to 15 – 20% of the total land area and allows for the soil structure to recover. Over time, water infiltration and root penetration will expand, demonstrated by an increase in yield (Tullberg 2000; Tullberg et al. 2007; Hamza and Anderson 2005; Antille et al. in press). The 1.5 m row-spacing enables enterprise integration through crop rotations with grains. Currently, 3 m is the factory standard wheel track width of a combine harvester. It is simpler for other machinery (e.g. pickers and spray rigs) to be adjusted to this track width than to adjust the combine. The combine is required during wheat harvest, the other major crop in a cotton rotation (Chan et al. 2006). Hence compaction is minimised on the entire farm all year round. The benefits of CTF are then experienced by all crops.

Conventional row-spacing in Australia is on 1.0 m rows (CRDC 2013). The reason being, that this was the width required for a mule to pass between crop rows with minimal trampling. Since then, multi-row cotton pickers have been arranged to fit this 1.0 m standard. Progressively plant breeding and cotton genetics followed suit and were evaluated on their ability to yield successfully in this configuration. CTF cannot be implemented in these systems as machinery would have wheels on a hill and a furrow in a 1.0 m row-spacing configuration (Masek et al. 2010) (Figure 1). Machinery implements would have to be offset to compensate for the three rows that would need to be picked in one run as opposed to the normal two. The centre for gravity would be quite high creating an engineering issue. Logistically this would become unnecessarily difficult (Tullberg et al. 2007), especially since 1.5 m wide row spacing accommodates for 3 m tracks comfortably.

In recent times other configurations have become increasingly more common (Clark and Carpenter 1992). These include Ultra Narrow Row (UNR) (< 0.4 m) and Narrow Row (0.75 m) (Roche et al. 2006). Row configurations influence yield, plant vigour as well as WUE (Figure 2). To determine the most suitable row spacing farm managers must consider a variety of factors. These include water availability, local climate, soil type and machinery logistics (Roth et al. 2013). Increasing or decreasing row spacing from the conventional 1.0 m can provide various advantages and disadvantages (Clark and Carpenter 1992). UNR and narrow row spacing reduces time to crop maturity (i.e. when the plant stops producing new fruit) and increases in yield per hectare (Brodrick and Bange 2010). This is important in regions where cotton seasons are particularly short (e.g. Riverina in NSW) (Jost and Cothren 2001; Brodrick et al. 2013). CTF can be implemented into a narrow row system but WUE is found to decrease with decreasing row-spacing, therefore it is not a suitable configuration for the water limited regions of northern NSW (Stone and Nofziger 1993). A substantial amount of research has been conducted on UNR and narrow row spacing in cotton (Clark and Carpenter 1992; Jost and Cothren 2001; Brodrick and Bange 2010; Brodrick et al. 2013). However little is known about the effect of 1.5 m row configurations on WUE, yield and fibre quality compared with conventional row spacing

Dr C. Owen Gwathmey was invited to Narrabri for an 8 week scientific exchange (Feb-March 2014) to share knowledge in cotton agronomy and physiology and provide mentorship to a new generation of cotton cropping specialists. Dr Gwathmey is a professor emeritus at the University of Tennessee in Jackson specialising in cotton agronomy and physiology. His research has a number of synergies with research undertaken by in Australia, on cotton physiology and management.

The purpose of Dr Gwathmey’s visit was to collaborate with Drs Brodrick and Bange in reviewing worldwide research into row spacing and plant population both which an area of research of continual interest to both U.S. and Australian growers. The review compares findings between studies; discuss possible reasons for differences in plant responses to density in different environments and clearly articulate opportunities where population provides an agronomic solution for improved yield, quality and resource efficiencies.

In February and March, Dr Owen Gwathmey worked at ACRI Narrabri, in an 8-­‐week

Scientific exchange with CSIRO hosted by Dr Rose Brodrick and Dr Michael Bange. During this period Dr Gwathmey attended industry field days, gave a seminar on his research in West Tennessee and met with many industry and research staff. The main focus of his visit was on developing concepts and reviewing data from published and unpublished research on two topics:

• Cotton row spacing/plant density, and

• Timing of crop maturity

During his visit Dr Gwathmey assembled two comprehensive Endnote databases as part of a worldwide review of literature relevant to the topics and we developed substantive outlines on the two topics as the basis for future manuscripts intended for publication and dissemination to growers and industry. Our work on these manuscripts is continuing.

In addition, Dr Gwathmey met with Drs Greg Constable, Shiming Liu and Warwick Stiller to obtain breeders perspective on these topics.

Dr Gwathmey also met with several younger cotton researchers in Narrabri, Katie Broughton, Dr Jenny Clement, Dr Onoriode Coast, Dr Warren Conaty and Dr Nicola Cottee providing mentorship in crop agronomy and physiology to these researchers.

Collaborations between cotton scientists in Australia and the USA have continued as an outcome of this visit with Dr Warwick Stiller visiting the West Tennessee Research Station during a visit to the U.S.A this year.

Dr Gwathmey actively contributed to discussions at field days that he attended during his visit, providing insight in particularly into the fundamental principles behind management for early maturity and mepiquat chloride (Pix) and differences in the climatic conditions in the U.S.A and Australia that might influence management decisions. Feedback from growers and consultants attending these field days was very positive about having access to an expert in this area to provide clarification around some of the management differences between the different environments.

Each year, Crop Consultants Australia - with support from CRDC - conduct a qualitative survey of cotton consultants regarding their practices and attitudes, as well as those of their cotton grower clients. The resulting report provides valuable information to the Australian cotton industry regarding on-farm practices , helping to benchmark the industry's performance in a range of key areas over time. This report, published in April 2020, looks at the 2018-19 cotton growing season.

Solenopsis mealybug is an emerging pest of cotton in Australia. Since their first outbreak in Emerald and the Burdekin in 2009, solenopsis mealybug have spread to the South Burnett, Darling Downs and St George regions with the potential to spread further and become an industry-wide pest. Overseas research documents the potential for Solenopsis to cause significant crop damage and describes the diffculties of effective management (Hodgson et al. 2008, Arif et al. 2009, Nagrare et al. 2009). The development of an effective management strategy for solenopsis mealybug will be underpinned by developing a comprehensive understanding of the pests ecology and biology, natural enemies and potential for chemical control within the context of the Australian cotton farming system.

Mirids are a regular pest of Bollgard® II cotton, requiring 2-3 sprays every season. However, pesticide use for mirid control can be problematic within an IPM program due to the disruption of natural enemy complexes and potential flaring of silverleaf whitefly and other secondary pests. The lack of selective or soft insecticide options means that effective monitoring and the judicious use of insecticides, guided by empirically derived thresholds is critical. The cotton industry has invested much effort into the development of thresholds for mirids, but recent evidence suggests that many growers and consultants do not use these thresholds (Whitehouse, 2006). It is important that we understand why adoption is not at expected levels and explore both the technical and social contributors in order to provide appropriate support to growers and consultants as they implement IPM. Researching some of the techincal aspects including monitoring (sample sizes at different precision levels), effects of temperature on mirid feeding, IPM fit management options, relationships between organisms responsible for boll rot and transmission by stinkbugs could further improve adopton of IPM in managing mirids and stinkbugs.

The aim of this report is to present the results of the studies conducted on solenopsis mealybugs, mirids and stinkbugs to provide data that can be used to inform the management of these pests within the context of IPM in cotton.

Dryland Cotton * Premature Senescence or Verticillium? * Groundwater aquifers in the Missisippi * Crop Competition *N trial

This report, commissioned by the Cotton Research and Development Corporation, is exploratory

research designed to shed light on possible solutions or new ideas in the alternative energy space as

applied to the Australian cotton industry.

The broad aim of this project is to develop farmer-friendly resources to assist the Australian cotton

industry evaluate alternate energy sources that can be integrated into normal farming operations to

save energy, save money and reduce cotton’s carbon footprint.

The broad aim of the project was to assist the Australian cotton industry evaluate alternate energy sources that can be integrated into cotton farming systems to save energy, costs and reduce the carbon footprint of growing cotton.

The specific objectives were to:

- Review commercially available alternative (renewable) energy and fuel options.

- Assess the feasibility of commercially available alternative (renewable) energy and fuel options.

- Examine performance / characteristics of non-commercial alternative fuel sources and mixtures.

- Reduce operating costs and emissions of non-commercial alternative fuel sources and mixtures.

- Inform the cotton industry on opportunities, costs and greenhouse gas implications of alternative (renewable) energy and fuels.

The purpose of this report is to introduce the basics of energy and renewable energy. The uses of

traditional energy and alternative energy in agriculture, and their impacts on agricultural production

and environment are evaluated. Specific applicability of alternate energy sources in cotton production

is explored. Future research and development in the alternate energy sources is also identified and

discussed.

The key findings from the work were:

- Price, availability and ease of use are the most important factors when choosing an alternative energy source; environmental concerns were important, but to a lesser degree

- Diesel, LPG injection (for electronic engines) and electricity are similar in cost when expressed per GJ of energy output at the flywheel. Of these, LPG injection has the lowest emissions, followed by diesel. Electricity has the highest emissions of any energy source. Each of these options could be viable given different values for engine efficiency, electrical tariff etc., so growers will need to evaluate them based on their own specific circumstances

- B100 biofuels (100% biofuel) have negligible contribution to global warming, however their costs are much higher than traditional alternatives. Straight biofuels are hampered by the fact that there is no fuel rebate available

- B20 blends from waste feedstock, such as tallow, are close to being economic because fuel blends up to 20% still attract the full fuel rebate. These blends may be economical at different times depending on the relative pricing of B20 and diesel. Due to differences in calorific value and viscosity, biofuels have slightly lower combustion efficiency than diesel. These fuels would need to be around 2% cheaper than diesel for price parity.

- Coal Seam Gas (CSG) had the highest level of resistance to adoption. There is no current use and only 2% of respondents plan to use CSG. It was rated as ‘Not an option’ by 57% of respondents to this question with a further 4% selecting Potential but would not use it. This is consistent with the environmental concerns over CSG.

- Solar PV is an option to offset workshop and domestic electricity and is less feasible for pumping water.

- The reliability of wind in cotton growing areas is too low, and the generation costs too high, for wind power to be viable.

- Similarly, the reliability of water makes the economics of hydroelectric energy generation less attractive.

The fuels tested for performance and emissions were: diesel, cotton seed biodiesel, tallow biodiesel, low purity ethanol, algae biodiesel and LPG in combination with diesel and biodiesel. While the industry could be ‘self-sufficient’ by using cottonseed oil, it was the most expensive energy option due to low oil extraction rates.

This travel sponsorship funded the attendance of an Australian CSIRO researcher to attend the 77th Plenary meeting of the International Cotton Advisory Committee in the Ivory Coast representing the Australian experience with managing resistance and to demonstrate best practice.

During the past few cotton seasons in the CGA region there were approximately 20 spray drift reports per season, with nearly 40 unreported events per season. It is estimated that these events impacted 15-20,000ha of crop in our region alone. The 2015/16 Crop Consultants Australia survey estimated that 45,000ha of cotton was affected by spray drift. Spray drift events not only lead to yield reduction and so forfeited income but also leads to numerous social problems such as conflict between neighbours as well as damaging the image of cotton growers and ultimately impacting our social licence to farm. The objective of this funding was to provide educational and outreach programs for cotton growers in the southern valleys region, by partnering with other industries and organisations to cohesively fund various programs for the benefit of the growers in the region.

Southern cotton growers had the opportunity to tour northern cotton growing areas in 2017 and 2018 attending the Gwydir Valley CGA field days, meeting number of industry leading farmers and visiting their properties. These tours not only exposed growers to the cotton growing systems in the north and cotton research but it also provided a tremendous opportunity to network with growers from other regions, learn about alternative irrigation systems relevant to their farming operations.

A two fold objective was to target all local industries within the southern valleys CGA, and focus on the prevention and management of off target spray drift. A meeting was held in January 2019 attended by around 60 representatives from all agriculture and spray related industries including, dryland cropping and grazing, rice, grains and horticultural production systems, apiarists, local council weeds officers, irrigation companies and government departments. A stakeholder spray drift committee was formed and since then, Stop Off-Target Spraying Riverina Valleys Inc (SOS RV) has been formed. The SOS RV who meet monthly, ran a two day training event targeting advisors and agronomists in late October and a series of farmer focussed workshops also in late October.

The second objective was to organise and coordinate a trip to the northern valleys for growers in the southern region. The aim of this trip was to create an opportunity for these less experienced growers to explore the farming operations and learn about some of the cotton growing fundamentals in the northern valleys to ultimately increase their knowledge and develop and implement some of these methods in their own farming operations. In March, 18 southern growers and industry representatives were on the bus tour which included attending the 2019 Monsanto Cotton Grower of the Year Award Winner Field Day at Mundine, Goondiwindi as well as tour of Keytah and other properties around Moree.