Phase II of the Plant Biosecurity Research Initiative (PBRI) focused on supporting cross-sectoral co­ investment in plant biosecurity Research, Development and Extension (RD&E), facilitated through collaboration and strategic partnerships.

The delivery of PBRI Phase II was enabled by financial contributions from its members, comprising the seven plant Research and Development Corporations (RDCs), Plant Health Australia (PHA) and the Department of Agriculture, Forestry and Fisheries (DAFF). The PBRI Collaborative Agreement for Phase II commenced in July 2020, and was extended for further five years (Phase Ill) in June 2023.

In addition to the co-investment, PBRI Phase II also established several partnerships with key domestic and international stakeholders, formalised through Memorandum's of Understanding (MOUs). These partnerships have served as the foundation for enabling PBRl's membership to connect and engage with a wider pool of knowledge and capability for supporting plant biosecurity RD&E initiatives.

A comprehensive independent review of PBRI Phase II was conducted by Ag Econ. This review found that the PBRI delivered its strategic goals of prioritising and coordinating collaborative plant biosecurity RD&E.

The review found that PBRl's success was underpinned by the lean and agile membership base combined with the coordination efforts of the Program Director, which supported a culture of collaborative intent.

At the end of Phase 11, the PBRI was recognised as a:

• cost-efficient and sustainable model for co-investment in biosecurity innovation across plant industries
• focal point of plant biosecurity RD&E expertise relevant to plant industries
• facilitator of biosecurity collaboration and networks, linking researchers, industry, and government

Monitoring and evaluation and an enhanced communication of the PBRl's impact were identified as areas for improved delivery of the PBRI program. These areas will be included in a new work program for the Phase Ill as part of the PBRl's commitment to continuous improvement.

The new five-year agreement signifies the ongoing support by members for the PBRI collaboration model and its role in the Australian Biosecurity landscape. It is also an acknowledgement of the benefits and efficiencies delivered through the coordination of biosecurity RD&E priorities and investment across Australian plant industries.

This report describes how the PBRI continues to deliver a collaboration model aimed at minimising duplication in plant biosecurity RD&E investment.

The Australian cotton industry is considered a global leader in sustainable agriculture. However, herbicide resistance and problem weeds threaten the productivity and profitability of the cotton industry and the farming system. Over time, the industry is increasingly moving back to relying on residual herbicides to manage herbicide resistant weeds in cotton, in rotation crops and in fallows, with glyphosate now ineffective for controlling some grass and broadleaf weeds, and resistance to the grass herbicides (Group 1) and paraquat also becoming increasingly common.

With the increasing use of residual herbicides, comes the problem of crop safety to the following crop, an even more difficult issue in dryland cropping, where rotations are often determined by planting opportunities, but selection of a residual herbicide applied in the fallow may restrict these options. The issues are further complicated by the increasing range of herbicides available for fallow use, with multiple herbicides potentially applied and multiple applications within a fallow period common. On top of this, camera sprayers are becoming standard in the industry and it is common to apply higher than normal rates through these rigs. There is a big need to explore the potential for these herbicides and herbicide combinations and rates to damage following cotton and other rotation crops.

The primary research focus of this project was on the impact of residual herbicides applied to rotation crops and in fallows on the following cotton crops. Research was carried out over a series of seasons (replicated in time), on replicated, randomised field experiments, some with split-plot designs, in fields grown under typical commercial conditions. Components were tested at Warwick (Southern Qld), Narrabri (Northern NSW) and Leeton (Southern NSW). The experiments were on solid plant, irrigated cotton, picked with modified commercial pickers, and ginned to determine lint yield. Excessively wet conditions delaying herbicide applications and flooding in spring 2022 were challenging for some experiments.

Our research has highlighted: that a) residual herbicides used in rotation crops, fallows, and through camera sprayers have the potential to seriously impact following cotton crops, reducing seedling vigour and lint yield, and b) combinations of herbicides can be more damaging than expected, such that label crop-safety information may underestimate the potential damage from combinations.

However, the limitation of this work was that it could not test every potential herbicide, herbicide combination and application scenario. The largest of the experiments (at Narrabri) examined eight in-crop herbicides in two rotation crops (wheat and chickpea) and 9 fallow herbicide combinations, a total of 80 treatments, with four replications. While the findings from the results from this work are extremely valuable to industry, a common scenario in the cotton system would be two in-crop herbicides and two or more fallow herbicides, increasing the potential herbicide combinations four-fold or more (as herbicides other than the ones we used could have been included).

Future research should focus on the impacts of some of the more common multiple-herbicide strategies. The current work, for example, showed that the standard cotton herbicides are not causing issues for the following rotation crops. However, only single herbicides were considered, applied at cotton planting. The potential impact of multiple herbicides, some applied pre-crop and others in-crop is yet to be examined, but is likely to be damaging to rotation crops.

Further work is also needed to correlate herbicide soil and plant concentrations to crop damage as we note that with more residual damage occurring in the industry and increasing concern around damage from residual herbicides, there is currently no information that can relate herbicide concentrations in soils or plants to damage. Where a grower sees damaged plants, it is becoming increasingly common to test for herbicide residues. When a herbicide is detected from a laboratory sample, it is assumed that the detected herbicide has caused the damage. However, this may not be the case, and conversely, when no herbicide is detected, this does not necessarily indicate that a given herbicide is not causing the damage. We simply have no data to relate laboratory test results to plant damage and this needs to be addressed.

Herbicide screening showed that samples of awnless barnyard grass, feathertop Rhodes and windmill grass had some level of resistance to glyphosate, the Group 1 grass herbicides, paraquat and glufosinate. Theses levels of resistance have big implications for managing weeds. The resistance to glufosinate is surprising and unexpected and will diminish the value of this relatively new mode of action herbicide to the cotton system, especially if resistance occurs amongst broadleaf weeds.

The studies on emerging weeds highlighted the challenges of managing some of these weeds, especially as they develop herbicide resistance. Cotton growers and consultants need to be aware of these issues with these weeds and develop management strategies for fields where they become problematic.

This research has generated a bulk of experimental results that will be published in information sheets, articles and scientific papers, and delivered to industry through the CottonInfo network.

Already from this project there have been a series of scientific publications, articles, conference presentations, many presentations at grower meetings and conversations with growers and consultants. More presentations and articles will follow. 
 

Many growers are unable to utilise new and transformative technologies due to their farm location not having access to a phone signal and or acceptable internet capabilities. Mobile black spots create limitations to productivity, profitability, sustainability, and safety of Australian cotton farms. As with the other regions of the world, the next biggest movements in productivity and growth for future generations will come from technological advancement. The level of Agtech development occurring throughout Australia is quite impressive; however, there is one considerable barrier to entry for many producers: the infrastructure connecting these devices to the internet.
The risk to the Australian agriculture industry is our lack of internet connectivity in rural regions, which restricts our ability to adopt the latest technological developments.
 

DNA is a reliable indicator of background disease inoculum levels. The value of that background diseaseinoculumisthenareliableindicatorofspatialdiseaseriskandsubsequentcropyieldsolongas other crop production variables are eliminated or accounted for such as:

• The pathogenic virulence of the strain of Verticillium
• Fusarium
• Plant population and uniformity.
• Irrigation management
• Nutrient availability and distribution – spatially and at depth
• Compaction
• Weather conditions

The cotton industry needs access to a diagnostic test for Fusarium oxysporum (F.ov). Fusarium is the dominant pathogen in southern Queensland and parts of the Macintyre and Gwydir Valleys. Not knowing the levels of F.ov thwarts the accuracy and scientific benefit of the Vert/BRR test in those valleys. This should be an imperative for future funding and research.

Inoculum maps are already being used to assist:

• Target trial locations onto sites with known levels of background disease:
• CSD to improve the site location of their V Rank and disease management trials.
• CSD to assess the impact of certain Xtend Flex varieties have on resultant inoculum.

• Chemical companies targeting low, medium or high levels of disease inoculum for efficacy trials.
• Chemical companies testing products for efficacy can now also add the treatments impact on resultant inoculum.
• Source sites with either Defoliating or Non Defoliating dominance.
• Monitor the impact of alternative crops on disease inoculum levels. CAS are the primary service provider for monitoring disease levels as part of the Richard Williams Disease Initiative to identify crop management practices that can assist with on-farm disease management. It is a grower participatory project to encourage growers and consultants to assess the value and cost of alternative practices across different farming systems and environments.

It is premature to make any recommendations on the predictive Yield Loss Risk as determined by DNA inoculum levels for BRR and Verticillium. Further research, taking into account the strain of Verticillium, is required for any yield loss thresholds to be set. Having said that, it does enable prioritisation of fields, to be planted to cotton, based on inoculum population densities and spatial distribution.

Cotton consultants now have these DNA diagnostics as a reliable tool for the detection, measurement and management of cotton disease on behalf of their clients. Consultants have the responsibility of protecting their clients crops from biotic threats, of which disease is often the most damaging. Disease management takes a long term and integrated approach. No longer should the grower be solely responsible for crop sequencing and field preparation, consultants need to be actively involved to in crop management earlier during the preceding years and during the fallow period. Consultants can use these disease inoculum measurements, to run their own trials and case studies.

• to establish their own field thresholds,
• assess the efficacy of specific agronomic practices such as crop rotations, N management, irrigation management and
• assess any yield impact of crop products and/or the impact of resultant inoculum levels.

Over time, by taking many more data points and with the advent of Interpretive Machine Learning, these and other data sets will provide the basis for establishing not only the direct interactions of Inoculum x Disease x Yield, but also their responses to specific weather conditions. For example, for a particular field with known inoculum levels, physical and chemical soil properties and elevation…what will the yield outcome be in a Decile 2 rainfall (hot and dry) year v a Decile 9 rainfall year (wet and cool). This could be further refined into specific weather Deciles for rainfall and temperature during specific crop stages (Day Degrees) x Month. Intuitively then and ultimately, yield loss estimates could be used relative to known objective measurements and according to a long range weather forecast. Similar retrospective findings could be associated with the confirmation of the virulence of the strain of Verticillium for each field.

I (Dr Karen Kirkby) received an invitation from Dr Jason Woodward from Texas Tech University and Dr Terry Wheeler from Texas A&M AgriLife Research & Extension Center at Lubbock to visit the laboratories at the Lubbock Center and visit production fields throughout the High Plains as well as to learn their isolation techniques used to quantify Verticillium dahliae from soil following the APS Meeting in San Antonio. This travel would allow Dr Kirkby to attend and present (should her abstract be selected), the APS Annual Meeting in San Antonio from the 5th-9th August followed by a two week visit in Lubbock between 10th and 26th August, 2017. 

The meeting titled Changing landscapes of Plant Pathology will hold field trips, APS Connects – Networking events as well as workshops. The workshop titled Morphological ID of phytopathogenic fungi held on Saturday 5th 9am – 4pm is particularly relevant along with the special session on the re-emergence of bacterial blight. 

My abstract submission titled “Genetic and morphological characterisation of Verticillium dahliae collected from cotton crops throughout NSW, Australia” has been submitted. Presenting this research to an international audience will be used to demonstrate the difference characteristics of Australian Verticillium dahliae isolates in comparison to those published in literature to date.  It will also outline the successful international collaboration between NSW DPI and Spanish collaborators.  Attending the workshop titled “Morphological ID of Phytopathogenic fungi” will provide the opportunity increase diagnostic skills and learn techniques used to identify pathogens of interest using morphological characteristics. 

Extending the trip to include a two week visit with Dr Jason Woodward and Dr Terry Wheeler will have direct benefits to my current research project “Managing Verticillium risk for Cotton”.  Both Jason and Terry developed the risk matrix for Verticillium and inoculum levels currently used in the USA.  The opportunity to work with these researchers will enhance my understanding and skills surrounding the development of a similar risk matrix for Australian cotton industry and these relationships will remain invaluable progressing forward.

CRDC and NSW DPI investment in cotton pathology research capacity at ACRI has increased since 2016-17 with the initiation of three new pathology research projects and the appointment of Dr Duy Le and Ms Aphrika Gregson. 

During a review of cotton pathology research infrastructure NSW DPI and CSIRO identified significant deficiencies in autoclaving capacity at the Australian Cotton Research Institute – Narrabri. 

Access to autoclaving technology is essential for many NSW DPI and CSIRO research programs based at ACRI as the current unit performs cleaning and decontamination of laboratory glassware, media and waste. After careful consideration NSWDPI and CSIRO agreed to approach CRDC to secure industry funding to procure an additional 100 litre autoclave unit.

Additional autoclave capacity will support the analysis of key pathology issues and identification of potential solutions for disease control leading to delivery of improved integrated disease management strategies for cottongrowers.

The Australian cotton industry has made considerable yield gains by improving genetics and agronomic management, which is ultimately limited by the environmental constraints in our growing regions. One of the major factors limiting yield in Southern NSW is the unpredictably cool start to the cotton growing season. This has a negative impact on grower’s ability to establish a consistent plant stand within an optimum planting window that allows sufficient length of season to obtain high yields.

Germinating cotton seed is an interaction between soil temperature, moisture and seed/soil contact. Depending on the season most growers are able to achieve a uniform, consolidated seed bed for optimum seed/soil contact but must react to fluctuating temperatures and consider irrigation water temperature at the time of planting. 

The results from this project suggest there is no silver bullet to improve yields. The attempts to improve crop establishment and increase early season growth returned nil significance during the seasons they were tested. The main outcome present across all experiments was that other agronomic management such as soil health, pest and disease pressure and seasonal environmental challenges limited the yield more than treatments imposed to affect establishment. 

Application of plant hormones to increase early season growth and boll loads have returned mixed results from work conducted in Australia and internationally. Irrigation and nutrition management play a large role in the efficacy of such products having an influence on yield components. For example, where soil conditions resulted in the crop experiencing potassium deficiency late in the season and undergoing early senescence, a review of the treatment effects of the products used is required. This work needs further investigation targeting compensatory growth and stress alleviation.   

Technologies such as biodegradable plastic applied over the seed line show promise to improve establishment but is highly dependent on planting date. Early planted crops experience an increased response to temperature/moisture dynamics when compared to late planted crops. The exercise of applying this plastic is expensive and requires a yield increase of 1 bale/ha in order for it to be worthwhile. Therefore, yield gains expected from application of the plastic should be done so on fields where there is no expected yield constraints from other factors such as disease or nutrition. 

Evaluation of factors limiting yield potential should be considered from a whole farm perspective and not just one facet of crop agronomy. While achieving a consistent plant stand is crucial to achieving high yields; other factors like nutrition, irrigation management, pest and disease control and seasonal conditions have a considerable influence on yield. Tackling all of this to improve yield is a massive task but over time with the skill set of the Australian cotton industry it can be done. 

The Australian cotton industry is a global leader in water use efficiency. As irrigation water continues to become an ever-more-scarce resource, the industry is increasing its commitments to continuous improvement in water productivity and demonstrating its responsible use of the shared water resource. 

This five year research and development project focused on improving on-farm water management and boosting productivity through the efficient use of water resources. This has been achieved through primary activities that included (1) the development of the weather based technology IrriSAT to guide irrigation scheduling, (2) the provision of a technical specialist to lead and coordinate industry wide water use efficiency campaigns and (3) benchmarking water productivity across the Australian industry and identifying long term trends in water productivity over the last three decades. 

The refinement and promotion of the IrriSAT technology to guide irrigation water scheduling has resulted in excess of 1500 growers and consultants becoming registered users. This has been achieved as a result of a range of promotional activities including webinars, workshops and field days. Commercial industry service providers have also taken up the use of IrriSAT, with Goanna Telemetry now having fully integrated the IrriSAT approach into their GoSAT web interface, integrating soil moisture probes and IrriSAT data into a combined irrigation management package for growers. 

To support and coordinate the improvement of irrigation management and water productivity in the cotton industry, three officers have provided Technical Specialist input to the CottonInfo team – Janelle Montgomery, Ali Chaffey and Ben Crawley. These officers have been incorporated in the CottonInfo team and have led a wide range of activities. These activities have included, the Irrigation and Nitrogen tours, which brought together researchers, advisors and growers to raise awareness of industry funded research programs and promote best practice, engaging with 519 participants across seven locations in eastern Australia. More recently, the Technical Specialist, in partnership with the CottonInfo team, has coordinated two major field days where approximately 220 growers and advisors were directly exposed to the latest technologies using siphon-less irrigation methods. Participants provided clear feedback that they had gained knowledge which would result in them making informed decisions regarding adoption of more efficient and water productive irrigation practices.  The field days have resulted in YouTube videos and detailed information booklets which are now being accessed by growers across the industry.

Benchmarking of water productivity has shown that growers continue to produce more cotton from less water – improving their status as the most water efficient producers in the world. Long term trends in rainfall and irrigation inputs have declined over time, but increasingly higher yields are still being produced. This has meant water productivity has increased at a rate of around ¼ bale more cotton per decade from each ML of total water, and roughly 1/3 more cotton per decade for each ML of irrigation water. Water productivity has improved from 1.12 bales per megalitre in 2012/13 to 1.20 bales per megalitre in 2017/18. Cotton growers are improving their management of irrigation water, for example by reducing losses to evaporation and seepage during transmission and storage losses. A comprehensive study of long term trends in irrigated cotton water productivity has been completed and its results are nearing publication in the scientific literature.

This research is helping to quantify and demonstrate that cotton growers are improving the productivity from every drop of water available, and this provides a platform for the industry to demonstrate and communicate its high level of stewardship of a crucial natural resource that needs to be shared – water.

Additionally, more efficient techniques have been developed under this project to monitor water productivity. An interactive dashboard has been developed which allows all growers participating in benchmarking, and their advisors, to track their level of water productivity, and more importantly to compare it with their peers, regionally and nationally. Further research is now taking place under a new project that will apply these new techniques to more closely identify the trends and drivers of water productivity, on an annual basis in both irrigated and dryland Australian cotton.

If cotton is the crop of choice in many irrigated systems it is because the industry has made great gains in water productivity and cotton is the most profitability use of the limited water available to growers.

For further information please contact 

david.perovic@dpi.nsw.gov.au or ben.crawley@dpi.nsw.gov.au

The NSW Government through its $50.8M World Class Food & Fibre 2 program allocated $5.7M to the upgrade of soil and plant research infrastructure at the Australian Cotton Research Institute (ACRI) based at Narrabri to meet the current and future research capability requirement to underpin food and fibre production in NSW. The project involved the construction and installation of equipment to support the operation of a new Plant Propagation facility and a new Soil and Plant Processing facility. These new facilities will support research into key research areas for the industry in agronomy, entomology, pathology, nutrition and soils.

CRDC provided a capital contribution of $475,000 to the ACRI program to facilitate the purchase of critical research equipment for the new facilities including:

- Growth Cabinet - Steridum PLEDT-RH500

- Leaf Area Machine - Licor LI-3100C

- Incubator - Steridum i170 

- Soil Oven - ODH50 

- Bioline Growth Room BDW80, and

- Laboratory Water Purification System, and

- 160KVA Diesel Generator

The equipment has been installed and is being used by research teams in the delivery of current CRDC funded research projects.

The Grains Research & Development Corporations (GRDC) also contributed an allocation of capital funds ($786,216) to the establishment of the 2 new facilities at ACRI. GRDC acknowledged that many cotton growers are also grain growers and that grain production is component of the cotton farming system.

The Supporting Southern Cotton Production project (DAN2001) was established in 2019 to research production issues identified from the agronomic information in grower surveys conducted by a previous project (DAN1701) over the 2016 and 2017 seasons. The survey found that cotton establishment and replanting remained the most difficult management challenges in the Southern 
valleys, with 30% seedling mortality and replanting outside the 2-week planting window resulting in a yield loss of 1–2 bales/ha. Other major influencing factors around these challenges included soil temperature, hot and cold shocks, seed depth at planting, irrigation water temperature and soilborne diseases in back-to-back cotton.
Operating alongside the Supporting Southern Cotton Production project was the Southern Cotton Crop Protection project (DAN1903). It was established in 2018 to address the crop protection issues faced by southern cotton growers and provide disease and invertebrate pest research and development expertise to the expanding Southern cotton industry. Real and perceived disease and insect threats to Southern grown cotton identified at the time included its relatively short production window, a high proportion of back-to-back or short rotations with cotton, a lack of southern specific management guidelines, and strong drivers towards continued high pesticide use with new growers being unfamiliar with cotton physiology and many relatively inexperienced 
consultants, primarily working for resellers, making crop protection recommendations, The two projects were merged in 2020 under DAN2001. All milestones for both projects were retained.