This project aimed to improve cotton irrigation WUE using dynamic deficits to (i) avoid plant stress and maximize yield and (ii) make the most effective use of in-crop rainfall. Our analysis of a large data set of soil water x plant stress (using as a measure) x climate experienced by the crop confirmed that atmospheric vapour pressure or evapotranspiration (ETo) can alter the plant stress response at the same soil moisture content. That is, if ETo is high a plant will may experience higher stress at higher soil moisture levels, and conversely if ETo is low a plant might not be stressed despite lower soil moisture availability. This analysis includes six experiments from three previous projects and three further experiments from the current project.

Two years of large scale field experiments have found that there is considerable utility in delaying irrigation timing and extending opportunities to capture rainfall when ETo

was low. This allows for more flexibility in cotton systems that require a significant number of fields to be irrigated at a point in time, and potential irrigation water savings. In both years there was no detrimental effect on yield or water use efficiency. In 2009/10 there was no difference despite considerable delays (up to 6 days) in one irrigation, and in 2010/11 the forecasted low ETo period also allowed an opportunity to capture rainfall event resulting in water savings of 0.8 ML over the season in one treatment. Periods of low ETo are often associated with a depression or low pressure weather front which may bring an opportunity to capture rainfall. Yeates found that delaying irrigations without taking into account ETo during flowering could have significant impacts on yield with a yield loss of 2.7% for every day that an irrigation was delayed.

Results from the past two experiments have indicated the need for a measure of plant stress used with soil water measurement to assist with a dynamic deficit irrigation approach. The results are showing that even when there are instances of high ETo, crops are not as stressed based on current understanding. We could continue to approach further analysis of the dynamic deficit approach without a measure of plant stress, changing the deficit accounting for crop stage, crop size, and boll load. This was similar to the approach used by HydroLOGIC to assist timing of irrigation.

The outcomes of the experiments in this project showed that there was considerable utility in delaying irrigation timing and extending opportunities to capture rainfall when ETo was low. This allows for more flexibility in cotton systems that require a significant number of fields to be irrigated at a point in time, and potential irrigation water savings.

The continuation of the research will involve determining a framework to provide a method to predict plant stress (based on a continuous measure) which couples current and future soil water with short term ETo forecast along with crop stage. This would allow the dynamic deficit approach to be used confidently and will accommodate local conditions. The approach used presently uses an average response of soil water, plant stress and ETo. There is also an opportunity to continually and directly measure plant stress directly using canopy temperature easily and being able to couple this with both soil water and forecast ETo would establish the value/risk of bringing forward and delaying irrigation.

The N trial at Milo, an impromptu field day at Boolooroo in April. Agro Update with Rob Holmes, Time of Planting - Some Interesting Results

Irrigated vineyards in Australia have seen extensive adoption of drip irrigation. At the start of this project there was concern about the sustainability of drip irrigation based on previous field observations. Drip irrigation conserves water but the concentrated nature of its application was believed to cause serious soil structural decline directly under drippers. This project aimed to identify such decline under drippers in Barossa Valley vineyards, to establish the causes of the decline and to suggest management and monitoring strategies to deal with the problem.

To identify such decline we adopted a “paired site” approach and examined subsoil structural problems, at depths of 30-50 cm, directly under drippers, midway between well-spaced drippers (>2 m) and at nearby non-irrigated control points. While we were encouraged to find no evidence of any preferential subsoil structural decline under drippers, we were surprised to find that all the subsoils we examined were of such generally poor structure that there was little prospect of further decline. However, we also realized that application rates in the Barossa Valley are dwarfed by those used elsewhere and proceeded to extend our investigation to the finer-textured soils of Sunraysia and the Murrumbidgee Irrigation Area (M.I.A.). The story here was no different and it became clear that the structural status of subsoils in vineyards is generally poor and is probably undermining good water use efficiency by vines. In 22 distinct soils air-filled porosities were universally very low, resistance to root penetration was high and infiltration rates were frequently poor. A comparison of root length density with subsoil structural properties strongly suggests that poor aeration poses the chief limitation on root proliferation and water use efficiency.

There are few strategies available for subsoil structural improvement in the vine row. We confirmed that gypsum alone has no significant benefit in improving poor structure at depth when applied to a red-brown earth. An attempt to induce subsoil cracking by drying soil in an extended partial root zone drying experiment also failed to improve subsoil structure.

These are inherently poor subsoils and there is a clear need for greatly improved preparation procedures ahead of new plantings. There is also need for changes in the management of existing vineyards if efficiency of water use is to be improved. We believe these will necessarily include modified traffic, soil mounding and the use of calcium, mulching and cover crops in the vine row. Indeed, the recommendations of Cockroft for the stone fruit industry (Murray, 2007) seem just as relevant to viticulture but have not been demonstrated or adopted. In their review of soil properties in relation to vine performance, Lanyon et al. (2004) have also recommended that much closer attention be paid to soil preparation and management in vineyards.

Novel approaches to irrigation scheduling are becoming critically important as water resources in the Basin come under increased scrutiny. It has been well known for a long time that through increased measurement of plant water requirements, one can dramatically improve yield and quality with less water. However, the challenge has been in implementing the science in a way that accurate and easy to use. This challenge clearly remains since the current uptake of smart irrigation scheduling system is less than 10%. One important reason for this is the lack of irrigation scheduling techniques that can be adapted or scaled across a range of cropping systems with consistent outcomes.

Between 2004 and 2008, the Victorian Government, through the STI grants, funded a joint research initiative between National ICT Australia, The University of Melbourne and Uniwater called Smart Irrigation. The purpose of this project was to develop low‐cost wireless sensor networks and irrigation scheduling algorithms for dairy, viticulture and horticulture. This project demonstrated up to 30% water savings in dairy irrigation and up to 75% increases in yield in horticulture. The project laid the foundations for future research in the application of intelligent sensor networks and control algorithm to irrigation science.

Current approaches to irrigation scheduling rely on point‐scale measurements of soil moisture. However, due to crop, soil and micro‐climate variability, decisions based on point‐scale data may not be optimal for the entire field. Overcoming this limitation requires a sensing system with a wider spatial coverage and a rethink of the algorithms that use this data, as well as existing point‐scale measurements.

In this project, we propose to develop a new scalable approach to irrigation scheduling and innovative algorithm for developing field‐scale water demand prediction models. Our algorithm will use more than one point‐scale measurements of soil moisture combined with low‐cost, low‐resolution thermal images and local micro‐climate data, to predict short‐term water demand. By combing point‐scale soil moisture data with spatial images, the algorithm will enables users to calculate water application rates that are optimum at the field‐scale, rather than focused on a single plant. This approach avoids the bias towards a single measurement point that is common in most irrigation scheduling techniques in use today.

Due to the fact of long experimental turnarounds and wide spatial distribution of sensing devices, the approach to separate device management will raise the cost and complexity of experiment. Alternatively, our approach employs low‐cost to establish a sensing system for data collection and remote storage. It provides user with a lower cost and more efficient way toreal‐time data access and remote monitoring in contrast with conventional ones.

The Australian cotton industry generates, on average, over $1.5billion per year in export revenue. About 80 per cent of cotton farms are irrigated and the farms are generally mixed enterprise operations. The returns for irrigated cotton range from $4,500 to $6,000/ha of income with profit before interest ranging from $1,000 - $1,500/ha. Thus, a cotton grower not only produces cotton, they produce other agricultural products such as grains, oilseeds, beef and wool. Cotton growers are very dynamic, innovative and adopt technologies which spill over to other broadacre food production industries. There are about 1,500 cotton farmers and about 800 cotton producing businesses in Australia. The industry employs about 10,000 people, most of them in the regional areas of Australia. About 70% of Australia’s cotton is grown in the state of New South Wales and contributes about $1.05 billion to the state economy.

The World Forum conference is aimed at gathering all men and women from all over the world who have excelled in their professional accomplishments, ideas and talents and either still active in their field or are Emeritus or Adjunct professors linked with Universities to present their work to the entire delegation of the forum. Delegates to the conference are by invitation only, and in 2010, delegates from 45 countries were invited to attend. The conference also attracts professional officers, scientists, high profile business executives of big medical companies, administrators, marketers, agriculturalists etc around the world for a symposium covering Agriculture, education, technology, science, international issues, health, publishing and the arts. It serves as a forum where these professional experts can interact and learn from each other. Scientists, particularly renowned agriculturalists, medical professionals, physicists, inventors are normally invited to attend the conference to present the papers in their area of specialty. In addition, an International Exhibition Gallery is opened at the entire duration of the conference for delegates to display their art, books, papers and other creative works. The World Forum conference is held every two years in different countries in the world.

Thus this provides an opportunity for researchers and eminent professionals to discuss and address pertinent research issues in their areas of specialty. Therefore, attendance to the conference not only increases one’s knowledge in their area of speciality but also broadens ones knowledge about other science oriented areas. For example Dr Robert Mensah an agricultural scientist was invited by the World Forum directorate to chair the Health Science symposium where neurosurgeon, cancer specialist, and community health specialists presented their fascinating research. Therefore, it is important for researchers from different science fields attend the World Forum to enable them not only update their knowledge in their specialty area but other science related areas.

The venue for the World Forum conference was St John’s College in Cambridge University in the United Kingdom from the 15 – 22 August 2010. The conference was well organised and provided an excellent forum for the participants to exchange ideas, update knowledge and discuss subjects of particular interest.

Herbicide damage is an ever increasing challenge for much of the cotton industry due largely to:

. the increasing complexity in the farming system (with a wide range of herbicides used),

. the increasing trend to minimum/zero tillage (using more herbicides for fallow weed control),

. difficulties in controlling fallow weeds (eg. fleabane and feathertop Rhodes grass), and

. increasing climatic uncertainty (need to treat weed flushes in a shorttime frame and maintain soil moisture).

Continuing herbicide damage is threatening the profitability of the cotton industry and in some areas may threaten the viability of the industry. Unfortunately, there is no easy solution. Crops generally will recover from herbicide damage, but in many instances with delayed maturity and reduced yields.

Over the last 3 years, CRC Project 1.01.49 has been developing a valuable

herbicide damage data set which will be expanded in the new project. This data

set currently gives detailed it Iformation on 2-4-D, bromoxynil, dicamba, MCPA,

glyphosate, Spray. Seed and Starane damage, with data from other phenoxy

herbicides to be added soon. Work is needed on the implications of lower rates of

2,4-D and multiple damage events and to further expand the range of herbicides and rates included in the database now available on the web.The 2nd part of the project involves the development of a readily assessable weed

control threshold for cotton. The threshold is essential if the industry is to fully realise the value of herbicide tolerant cotton.

The threshold based on the Critical Period for Weed Control was an important

outcome from project CRC 126 and a large step forward. The shortcomings of this threshold are that it

* is based on single weed types and does not integrate across types, and

* is based on a visual estimation of weed species and density which are difficult and time consuming to accurately measure over a whole field, where weeds are often patchy.

The next step is to develop a user-friendly, readily applied weed control threshold based on weed biomass, which integrates weed species and density.

This report covers the trip to attend the Sustainable Textile Leaders Roundtable (held 22/9), the ITMF ICCTM meeting (held 23/9) and the 2011 ITMA held September 22nd- 29th. The meetings and exhibits were held in Barcelona, Spain at Barcelona’s Fira de Barcelona.

The project titled 'Skills Profile and Labour Supply Structures on Cotton Farms' was funded by the CRDC and covered the period from March 2015 to August 2018. The main aim was to determine current and future labour needs on cotton farms and assess these against supply of labour to farms, identify gaps in meeting needs and recommend strategies to address the gaps. As part of achieving this broad aim, position descriptions were developed for recruiting employees on cotton farms. Furthermore, strategies used by farmers to retain core employees were assessed against industry trends to identify areas for improvement. The project enabled assessment of the extent to which current and future sources of labour would help the industry meet its goal of building a capable and connected workforce with the knowledge and skills to drive the industry and handle emerging challenges.

A qualitative research approach was used involving face-to-face and telephone interviews with various stakeholder groups associated with the research objectives. They comprised experts in cotton and associated industries, farmers, contractors, and labour supply firms. The interviews were transcribed with permission from interviewees and analysed for key themes. In total 11 experts, 32 farmers, 23 Contractors, and 10 labour supply firms were interviewed.

Three main positions were identified on cotton farms - farm hand, lead hand (or supervisor) and farm managers. Position descriptions were prepared for each and recruitment sources and selection processes identified, also for each position. Training was generally on-the-job and retention efforts involved providing incentives such as accommodation, vehicles, mobile phones and sometimes paying school fees of employees' children.

Even though large scale planting of Bt cotton started a decade ago, consequences on a landscape-scale have hardly been studied. Helicoverpa armigera and H. punctigera are highly mobile organisms existing across broad-acre landscapes that are constantly changing, yet little is known about how they respond to crop and non-crop composition and configuration. Using a robust sampling design we collected data on the abundance of Helicoverpa spp (eggs and moths) and egg parasitoids in Bt cotton and sorghum at the spatial scale of fields, groups of fields and landscapes (20 km diameter) across the Darling Downs, QLD over three years. Detailed land-use metrics were generated at various distances from each sampled field in each landscape and season. These data were combined and used in spatially-explicit statistical analyses to identify and predict how crop composition and configuration at the landscape-level and field-level influence Helicoverpa egg and moth density.

Helicoverpa armigera egg and moth density is strongly affected by landscape composition and configuration at the scale of landscapes, or tens of kilometres. The landscape explains most of the variation in H. armigera egg density in Bt cotton, not what immediately surrounds the Bt cotton field. The best-fit model accounts for 50% of the variance among landscapes with large areas of Bt cotton (at a scale of 1.5 km radius) having the biggest affect, resulting in fewer H. armigera eggs laid in Bt cotton. The explanation for this result may be that Bt cotton functions as a population sink and overtime fewer moths are available to lay eggs.

Combinations of crop at various scales could not explain Helicoverpa punctigera egg and moth density. This maybe because H. punctigera interacts with crops at a spatial scale larger than landscapes of 20 km diameter. No H. punctigera were found in sorghum. For H. armigera as sorghum fields increase in size so does the H. armigera egg density. However, sorghum surrounded by sorghum never has as many eggs as sorghum surrounded by Bt cotton. This could be due to either more immigrants to sorghum over time or moths less willing to leave sorghum when surrounded by large areas of Bt cotton.

In Bt cotton, there was a positive relationship between the number of moths (species not separated) and the field-level amount of Bt cotton at 0.5 km r. However this was only found for 2011-12 season. In sorghum, there was a positive relationship between the number of moths and the average landscape-level amount of Bt cotton at 1.5km r. The moth and H. armigera egg result are similar. There are more moths and eggs in sorghum surrounded by Bt cotton than sorghum surrounded by sorghum. Sorghum in a sea of Bt cotton either ‘attracts’ and / or ‘holds’ H. armigera moths.

Interpretation and Implications

These results provide clear demonstration of the importance of landscape composition and configuration. Further, variation was often best explained by landscape-level predictors, and less often by field-level predictors. This demonstrates the importance of area-wide approach to pest and resistance management. Further, the strength of selection for resistance is largely determined by the proportion of the population under selection. Our results allow us to identify and predict some of the factors contributing to eggs deposited by female moths in Bt cotton.

These findings have the potential for positive outcomes in relation to resistance management and area-wide pest control, however the ways in which they might be developed for application will be challenging. Regardless, our approach and results can directly contribute to selection of crop type, amount and location for delaying resistance in Helicoverpa spp.

Deficit (VPD)) and reduced water availability as a consequence of climate change is likely to

affect cotton production. However, there had previously been little research to assess the realworld

interaction of rising CO2, temperature, VPD and reduced water availability. To enhance

the current understanding of cotton system adaptation to climate variability and plan for

projected climate change, as a part of the National Facility for Climate Change Research

project four chambers were constructed at the Australian Cotton Research Institute (ACRI) in

Narrabri, NSW. These chambers have enabled higher atmospheric CO2 and warmer air

temperatures for field-grown cotton, throughout an entire season. The chambers have

successfully been used over three consecutive cotton seasons (2014-15 to 2016-17) in field

based research to further current understanding of the interactive effects of rising CO2 and

warmer temperatures on the physiology, growth, water use and soil microbial communities of

cotton production systems in Australia. Therefore, the development of the National Facility for

Cotton Climate Change Research has been, and will continue to be, a crucial aspect of

investigating the response of field-grown cotton in Australian production systems to projected

climate change.