An efficient plant biosecurity system is vital for protecting Australia’s $31.8 billion plant production industries and our unique environment from exotic plant pest threats. Research, development and extension (R,D&E) are a vital part of this system. In order to improve the R,D&E underpinning the plant biosecurity system a greater understanding of the gaps and inefficiencies of the R,D&E system are critical. This report aims to provide an analysis of some of the areas for improvement and provide recommendations from the National Plant Biosecurity R,D&E Strategy Implementation Committee (the committee) in order to improve the R,D&E system sustaining Australia’s plant biosecurity system. The National Plant Biosecurity R,D&E Strategy Implementation Committee can then pass these recommendations to relevant government departments, Rural Research and Development Corporations (RDCs) and other relevant stakeholders.

This project continued the major study of waterlogging on heavy clay soils after furrow irrigation or heavy rainfall. The experiments concentrated on cotton, but some detailed work was also done on summer legumes to study detailed reasons for yield reduction during waterlogging.

Healthcare associated infections (HAIs) are common in hospitals around the world, where patients get infected for reasons entirely unrelated to the purpose of their admission. Healthcare textiles have a ubiquitous presence in the form of healthcare workers and patients’ uniforms, bed linens and curtains. Numerous clinical reports have confirmed that the contamination of healthcare textiles with HAI-causing pathogens may result in transmission of disease to healthy patients, through health-care worker’s uniform, scrubs and hospital linen.

Incorporation of antimicrobial agents into textiles is increasingly looked upon as a solution to prevent the pathogen colonization. However, if the fabric is hydrophilic then the absorption of organic fluids (in the form of a sneeze, vomit) can jeopardize the antimicrobial activity. Therefore, there is a growing interest to incorporate dual functionalities, antimicrobial property and superhydrophobicity, into healthcare textiles; as a superhydrophobic surface can repel pathogen-rich fluids encountered in a hospital environment while antimicrobial functionality destroys the attached microbes. Obtaining durable functionality of both properties seems to be an elusive proposition for the researchers in this field. Therefore, developing durable dual functional coatings on cotton fabrics is the prime objective of this work. The work investigates the incorporation of a cationic antimicrobial compound into cotton textiles. The compound has no adverse effect on human health, unlike some of the existing metal-based antimicrobial agents (e.g. nanosilver). This study also aims to achieve the superhydrophobic effect by using non-fluoro hydrophobic compounds, owing to the toxicity and persistent nature of fluorine compounds.

This work reports novel methods of immobilization of antimicrobial agent and hydrophobic compound to cotton fibres. One-Pot coating method is relevant to textile industry as it can be adopted as a pad-dry finishing technique. The method is simple, rapid and suitable for bulk-scale manufacturing. The process consists of deposition of antimicrobial agent and a hydrophobic compound through the use of cross-linker. The experimental design revealed the optimum synthesis conditions and the inter-relation between the three constituents of the coatings. The incorporation of cross-linker has fulfilled three purposes: anchoring of antimicrobial compound to cotton, inter-linking of antimicrobial compound chains in the coating and bonding of hydrophobic compound to the antimicrobial network. The fabrics possessed the durable activity of both antimicrobial property and superhydrophobicity. Such a fabric would enhance cotton’s competitive advantage over made-made fibres in a range of markets including: health care textiles, sportswear, outdoor furnishings, and hospitality and defence services.

To summarize, the development of dual functional cotton fabrics is a promising solution in the fight against the transmission of HAIs.

Uptake for CottonMap was high for the 2018/19 season

• Approximately 86% of the total planted area was mapped

• Approximately 30,856 page views for the CottonMap

Despite significant investment in spray drift mitigation by the cotton industry, cotton crops continue to be impacted by herbicide misuse. This is reflective of spray drift being an issue that needs to be addressed via a number of channels, including training and education, and that while a mapping platform is a very useful and helpful tool, reducing spray drift requires a collaborative effort across industries and via a number of different pathways.

In response to feedback from users and a change in platform ownership, a decision was made to investigate alternative options to deliver a crop mapping service that would offer the following benefits:

• Ability to map other crop types, not restricted to cotton

• Improved usability

• Cost effective

• Ability to be agile and respond to changes in technology, link with other technology platforms to increase value for users and funding bodies

The low responsiveness of cotton (Gossypium hirsutum L.) to phosphorus (P) fertilizers in the field where soils have low soil test values for P, suggests that cotton is capable of utilizing soil P pools that are less labile or are below the depth of P fertilizer placement. The objective of this thesis is to understand how the cotton plant acquires P from less labile and subsoil P pools.

The first experiment was conducted using rhizoboxes to examine whether cotton is physiologically efficient at acquiring less labile P pools, through comparison with wheat (Triticum aestivum L.) and white lupin (Lupinus albus L.). Under P-deficient conditions, cotton released negligible carboxylates into the rhizosphere. The P depletion zone of cotton from rhizosphere soil was less than 2 mm, and predominantly from the relatively labile NaHCO3-Pi and NaOH-Po pools. In contrast wheat and white lupin markedly depleted the NaHCO3-Pi and less labile HCl-P pools, and the depletion zone extended to 3 mm. The depletion of NaOH-Po pools by cotton was associated with increased activity of phosphatises in the rhizosphere soil.

A second sand culture experiment investigated the ability of cotton to access P from the sparingly soluble P sources of AlPO4, FePO4 and hydroxyapatite. The experiment revealed that cotton was inefficient in accessing P from all these sparingly soluble P sources. In contrast, wheat showed an outstanding ability to use AlPO4. The 32P reverse dilution technique was then used to determine the variation between these species in accessing sparingly soluble AlPO4 and hydroxyapatite in a Vertosol when N was supplied as different forms. The inefficiency of cotton to access P from these sources was again documented. The percentage of hydroxyapatite recovered by the cotton plant was 8 and 10 times lower than that recovered by wheat and white lupin respectively, while the availability of AlPO4 to cotton was 10 times lower than wheat but 3 times higher than white lupin. Addition of N as NH4-N elevated total plant P uptake from all P sources except in the case of wheat fed with Al-P. The fate of these P sources in the soil was examined in a separate incubation experiment Sparingly soluble Al-P was more ‘labile’ in Vertosols, in comparison to FePO4 and hydroxyapatite which showed little change in availability with time.Hydraulic lift can be a desirable characteristic for P acquisition by crops growing in areas that experience frequent drying of the topsoil. A glasshouse experiment using specialized soil columns tested whether cotton could hydraulically lift water and whether this hydraulically-lifted water facilitates P acquisition from dry topsoil. Hydraulic lift was detected in a Vertosol for 7 days after water was withheld from the topsoil. However, the hydraulic lift detected for the cotton did not aid P acquisition from the dry topsoil. Therefore, it appears that if the topsoil dries out, P uptake by the cotton plant would rely mainly on P acquisition from P sources in the subsoil.

The contribution of subsoil P sources to plant uptake was investigated in two field surveys. Soil samples at various soil depths were collected from continuously-cultivated cereal and cotton paddocks, and corresponding virgin sites, in north-western NSW. Regardless of P fertilizer history, organic and residual P pools at depths of 0 to 45 cm had been invariably depleted following long-term continuous cotton and cereal cropping. With a negative Pbalance, the HCl-P pool below 10 cm also declined significantly. Thus, routine soil P tests, using alkaline bicarbonate extraction solutions with soil samples collected from the topsoil layers (above 10 cm), were less accurate in estimating P responsiveness of cotton to P fertilizers applied on Vertosols. The effect of cropping system, expected from species ariation in root morphological and physiological characteristics, on the soil P accumulation and depletion profile was undetectable.

The results suggest that the low responsiveness of cotton to P fertilizers can be attributed to a number of causes. These include the utilization of organic P pools, subsoil P exploration or possibly mycorrhizal symbioses, rather than any efficient P acquisition from sparingly soluble inorganic P pools in the topsoil. Further research should focus on accurately estimating the contribution of organic P and subsoil P pools to P uptake by cotton plants.

The objective of this project funding was to maximise profitability by improving the efficiency and flexibility of broadacre irrigation systems. This was identified as a priority for research by grower groups based in the southern connected systems of the Murray Darling Basin. To achieve the objective, the project had four focus areas:

* to foster collaboration and partnerships to facilitate the adoption of research findings

* to investigate irrigation and nitrogen management strategies to improve water productivity in cotton, maize and rice farming systems

* to develop best practice design guidelines for basin surface irrigation systems

* to investigate the economic impact of investment in irrigation development on whole-farm profitability.

The key messages:

* This project enabled collaboration across two research organisations, four advisory organisations and three grower groups to investigate improvements in water productivity in a region in which approximately 4000 gigalitres (GL) is used by irrigated agriculture.

* Complex relationships exist between irrigation, nitrogen and plant development that require appropriate management to avoid negative impacts on profitability.

* Improvements in on-farm irrigation infrastructure can achieve a significant marginal rate of return on the capital investment, with potential for further improvement subject to better irrigation layout design and drainage.

Alternative and renewable energy sources, including solar for powering cotton production, were hot topics at the February 2015 CottonInfo Big Day Out at St George, QLD. One of two Big Day Outs, the Gunnedah event was hosted by cotton grower Scott Morgan, with support from CottonInfo, its partners CRDC, Cotton Australia and CSD, and the Commonwealth Department of Industry and Science. This video provides a snapshot of the event and its key highlights.

A two year project that investigated the influences of weathering, insect honeydew and fungal agents on cotton colour grades, yarn and fabric quality parameters provided a better understanding of these factors and the conditions under which they occur. Extended weathering in the field, particularly with successive rainfall events totalling 100 mm, was detrimental to cotton colour, reducing colour from base grade to 41 and beyond. In both years of the project this equated to 10 weeks in the field from the time of first open boll. Moist, overcast conditions for 4 -7 days were usually followed by a drop in colour grade. Short, sporadic rainfall events followed by sunshine did not cause colour degradation. The humidity they provided could, however, further the development of sooty mould fungi which grew on honeydew contaminated cotton. While sooty mould fungi can grow on the natural sugars of immature fibres in the absence of moisture, both the presence of insect honeydew and rainfall strongly promoted their development, reducing cotton colour from base grade to 41 to 71. The magnitude of the colour drop depended on the amount of black spores on the boll surface. Increasing development of sooty mould fungi was also correlated with a reduction in sugar concentration on bolls, providing some evidence of the ability of fungi to remove sugar from honeydew contaminated cotton. Sooty mould spores in cotton fields are rarely just blown out during harvesting. It was found that spores strongly adhere to open bolls and survive through the harvesting process to worsen the colour grade of the harvested lint. However, one or twocolour grades may be restored through the ginning process. Between 30-50% of heavily contaminated sooty mould cotton in the total pick can drop colour grade from base grade to incur penalties. Colour grade, while not showing effects on lint or yarn quality in these experiments, was strongly related to dyeability of fabrics. Cotton colour degraded through weathering and rainfall affected dyeability more that colour degraded through sooty mould fungi and this was most likely associated with the lower moisture levels received by the sooty mould cotton. SEM scans did not show obvious surface changes due to sooty mould activity.

At this stage options for mitigation of the degradation of colour grade are not available. There is no mitigation for rainfall and growers already aim to harvest their crop as timely as possible to avoid weathering and colour degradation. Agronomic and management practices are being investigated in a continuing project. As colour degradation due to sooty mould development largely depends on the presence of sugars in the form of insect honeydew, the most important goal a grower should have is to avoid insect pests such as whiteflies, aphids and mealybugs. This can be achieved through sound, IPM guided crop management using IPM compatible insecticides to control early season pests such as mirids in order to preserve beneficials that later on help with management of Silver leaf whitefly (SLW). Should conditions conspire, and a crop is sticky without rainfall in sight, a range of scenarios may be managed with suitable knockdown insecticides which may reduce SLW numbers until defoliation is complete. On the other hand, if rainfall is in sight, sticky cotton can benefit from this but incurs the risk of sooty mould development. Fungicides tested in this project have the potential to prevent sooty mould development, however, none are currently registered for use on cotton (other than as seed treatment). If registration becomes an option in the future, many parameters would have to be considered including environmental impact, pre-harvest withholding periods, inherent effects on lint, application efficiency and cost. Further research into mitigation options are being addressed in CSP 1901“Reducing the impact of weather, insects and microbes on cotton colour”, a collaboration between Dr Simone Heimoana (Simone.Heimoana@csiro.au) and Dr Stuart Gordon (Stuart.Gordon@csiro.au). Management of honeydew related cotton discolouration is up to the individual grower and while sooty mould tends to affect the individual grower with colour discounts, sticky cotton has the potential to penalise the entire industry.

Declining water quality and quantity is a threat to the production of food and fibre worldwide. While irrigation using marginal quality saline-sodic (MQSS) water is emerging as a more common practice, it is still an under-utilised resource because of its potential detrimental impact on soil structure and crop production. The aim of the research was to enhance the current understanding of, and capability to, strategically utilise saline-sodic water as an irrigation resource through further investigation of the theory of threshold electrolyte concentration (C TH).

I attended the 3rd Agriculture and Climate Change conference held in Budapest, Hungary from the 24th-26th March 2019. The focus of the conference was on the various challenges of climate change, reduced water availability and approaches to the production of climate resilient crops, which is highly relevant to my current CRDC-supported research CSP 1804: Water use efficiency in a changing climate. Attending this conference provided me an opportunity to present CRDC-supported research on the integrated effects of warmer temperatures and elevated CO2 on leaf physiology, growth, water use and water use efficiency to the international scientific community. It also provided me an opportunity to engage and network with international scientists researching effects of climate change on a wide range of agricultural systems.