Final Report - Variety development and tillage systems for cotton production in the Ord Stage 2 development

In June this year, I spent three days in a light aircraft traversing what seemed like the length of the country, looking at cotton farms and meeting with the people who are making their living out of these enterprises. I have had a unique privilege of being invited to be on the judging panel for your cotton grower of the year awards. May I take the opportunity to thank the organisers of the awards for inviting me onto your panel. And can I especially thank the families who so kindly welcomed me onto your properties. It is truly a sign of the times that an industry such as yours cares to invite someone like me, who is pigeon holed as a greenie by many, to participate in this showcasing of your industry to the rest of the world It was an excellent opportunity to see first hand how your industry works on the ground.

Manual calculations of yield loss from pest infestations are complicated and time consuming. The CottASSIST Aphid Yield Loss Estimator allows the user to enter current Aphid samples to estimate a rate of pest increase and the potential effect on yield. This allows crop managers to ‘look ahead’ to decide on control options or if natural enemy populations are providing sufficient control.

It has been ten long years since the CoAG reform agreement was first formalised between the state and federal governments. In that time much has changed including how regional parties today approach and affect discussion on water reform. In the early days both sides (government agencies and water users) approached with caution, then anger, which was followed by consideration of fact, some more anger and then more recently a desire on both parts to listen, accommodate and try to achieve workable solutions. At least that is how it has been in the Fitzroy Basin, which covers approximately 142,000km' is Queensland's largest externalIy draining basin, home to seven major river systems, over 1400 licensed water users and innumerable plant and animal species. With such area and diversity it becomes easier to comprehend the enormity of the task that faced agency staff when they first addressed water reform in the Fitzroy, but at the time department officials felt it would only take six months. That was in 1997 and the participants are still tackling these issues today. The process has been long, the consultations many with mixed results, participants increasingly difficult to find, budgets cut during the process and fewer from industry coming back to the table each year. Despite all this, the results of engagement between industry and government in the Fitzroy have been impressive, and this paper highlights some of those achievements and the processes by which they were gained.

The winter edition of CRDC's magazine, Spotlight, tackles the ongoing threats posed by diseases and weeds. It investigates the partnership between growers, extension officers and pathologists, who are working together to make a breakthrough in the management of Verticillium wilt.

It also looks at research into weeds management and the development of tools to help growers manage herbicide resistance - helping to avoid scenarios experienced overseas, where weeds are becoming resistant to many modes of herbicide resistance. A newly developed predictive modelling tool can help growers determine both the resistance and economic outcomes of weed control programs.

This edition also explores developments in two CRDC-supported projects, aimed at specifically addressing the farming systems research needs of dryland cotton growers and cotton production management in Southern NSW. And it highlights examples of our investments in people and the impact they are making: from Nuffield Scholars to Young Farming Champions and Science and Innovation Awardees.

Finally, this issue also contains CRDC's list of R&D projects for 2018-19. This list highlights the scope and direction of our research investments as we enter the final year of the 2013-18 Strategic R&D Plan.

This project aimed to develop farming systems and extension materials and processes that support growers in producing high yielding / high fibre quality cotton more consistently, profitably and sustainably. It thereby contributes directly to the profitability and competitiveness of the industry. This has implication both on-farm but also for cotton's role in the catchment through more rational management of inputs, especially, water, pesticide, fertilizer and energy. A second contribution is to co-ordination and integration of much production related research and the linkages with myBMP.Key Outcomes: Interrogation of industry data relating management inputs to lint yield and fibre quality has demonstrated that positive changes have occurred over the past eight years. Although rates of nitrogen application continue to increase, the range of application rates has narrowed. The number of insect sprays has declined as has the number of in-crop irrigations, providing a positive image for the industry. The management factors affecting productivity and fibre quality tend to vary between seasons and regions, reflecting differences in soils and climate.The project has shown that planting date and cultivar selection has an effect on resource use efficiency and does not impact productivity, except for delayed planting.The project has also shown that there may be potential for thin biodegradable film in promoting emergence and for conserving soil moisture at planting. The benefits may be greatest for cooler regions as soil temperatures are elevated beneath the film, thereby accelerating germination and emergence.The current system of inter-cropping cotton and legumes in close proximity is not commercially feasible. The concept of spatial rotation is attractive given developments in precision agriculture, where crops can be precisely planted in the landscape. There are perceived benefits in being able to rotate cotton and legumes in the same space over time; soil physical, chemical and biological properties will change which may improve cotton root growth, water availability, nutrient supply and pest and disease resistance. There are no practical benefits at this point in time. Preliminary measures of soil strength have highlighted the possibility of subsoil compaction developing from the use of increasingly heavy harvesting equipment. Strategies need to be developed to minimise subsoil compaction and for amelioration in the long-term.An assessment on changes in soil organic carbon in three long-term experiments at ACRI was undertaken; where one has demonstrated nitrogen and carbon benefits from rotation with legumes, one has shown a benefit in soil carbon from rotations with both wheat and legumes and one the benefit from minimum tillage and including wheat in the rotation.

Wheat is nearly exclusively a dryland crop in the northern grains region of Australia (bounded in the south by Dubbo in New South Wales, and in the north by Emerald in central Queensland (GRDC 2010)). Cotton has traditionally been the favoured irrigation crop in the region, due to its higher profitability in comparison to wheat. In seasons of favourable water supply and prices, up to 400,000 ha of cotton has been produced in these irrigated areas (ANRA 2009). Wheat is commonly considered a beneficial dryland rotation crop that improves the yield and profitability of subsequent cotton crops (Hulugalle et al. 2006), through improved soil structure and decreased inoculum of cotton-specific diseases in the soil (Hulugalle et al. 1999 & 2006).In 2007/ 2008, grain prices improved to record levels in response to socioeconomic influences in Asia, an international push for bio-energy crops, and the impact of local droughts. With wheat prices nearly 300% of those received just three years earlier (Brown et al. 2008) high levels of optimism were generated for future grain prices. This increase in agricultural commodity prices sparked increased investment in grain farming from the corporate sector, and initiated a paradigm shift amongst the irrigated farming community of the northern grains region. These irrigated enterprises no longer viewed themselves as cotton growers, but rather, commodity growers needing to make the greatest return on the available irrigation water. And while grain prices have since eased, demand for food grain is predicted to increase over the next 20-50 years as the world's population expands (FAO 2006; UN 2007). Demand-driven increases in grain prices are therefore likely to result in increased irrigated wheat production across the northern region.Therefore there is a need for improved advice to irrigated crop producers that have traditionally grown cotton, but are now commodity producers who need to make tactical responses to water availability and commodity prices in order to maximise on-farm water use efficiency. This project aimed to assist irrigated growers in the northern region by producing irrigation scheduling recommendations for irrigated wheat, in conjunction with the CCC CRC 'High Yield Grains in Cotton Farming Systems' (HYGICFS) project.

To purchase additional instrumentation which will enhance existing experiments such that the rigorous scientific measurement and comparison of the water use efficiency of transgenic and conventional cotton systems can be made.

Integrated Pest Management (IPM) in cotton emphasises conservation of beneficial species (mainly insects and spiders) to suppress pest populations and reduce the need to apply insecticides. Many beneficial's encountered in cotton are ‘generalists’ allowing them to consume a range of prey, subsisting on non-pest prey when pests are scarce. These generalists are very important in managing pest species especially when the pests are at low densities. Disruption of these generalist beneficial populations, and the resulting reduction in mortality on pest species, can lead to outbreaks of secondary pests. This is especially a risk for fast life cycle species such as mites and aphids but also for pests such as SLW and Helicoverpa and probably also mirids and green vegetable bug(GVB).

Given the significance of generalist predators in biological control (75% of studies quantifying the impact of generalist predators report a positive suppression on pest species), it is surprising that we have a poor understanding of which species have the greatest effect on pest abundance in Australian cotton. This is further compounded because a number of pest species are also generalist predators, such as ‘phytophagous’ thrips species, green mirids and apple dimpling bugs. The lack of information reflects the difficulty in measuring predation by observation and impracticality of remote methods (eg video). However, knowledge of the key beneficial species would be valuable so that they can be targeted for conservation in crops. Further, it can also focus research to understand how these predators survive within the agroecosystem which may lead to strategies to enhance their abundance (e.g. conservation of native vegetation remnants on farm).

This project used ‘molecular diagnostics’ to identify the key predators of silverleaf whitefly (SLW; B. tabaci MEAM1, commonly known locally as B-biotype) and green vegetable bug (GVB, Nezara viridula) both important pests in current Bollgard II dominated cotton systems. This involved collaboration with Professor James Harwood, University of Kentucky, who has pioneered this technique and has extensive experience with its application in agricultural systems.

The Australian Cotton Comparative Analysis provides the industry benchmark for the economics of cotton growing in Australia. The report focuses on the economics of the 2016 crop from growers across the different cotton-growing valleys. It also presents trends that have been measured against more than ten years of data. This year, the report also includes per bale figures and excerpts from three industry reports which analyse cotton growing practices, workforce turnover and water productivity. The Cotton Comparative Analysis is a joint initiative of CRDC and Boyce Chartered Accountants.