Weather and climate news 27 September 2015

Weather and climate news 07 September 2015

The Grassroots Program offers Cotton Grower groups the opportunity to apply for community based assistance.

Weather Station Upgrades: The Darling Downs Cotton Growers Inc (DDCGI), and individual growers established 21 weather stations between the period 1996-1998, to provide growers with localised weather information to assist with on-farm management operations. The DDCGI has maintained these stations over this period, and in recent years, been working on major upgrades to digital technology to enable text communication with growers rather than the old analogue voice system. To date 11 stations have been upgraded by the DDCGI, and funding from this grant contributing to upgrading another four stations.

Chemical Application Workshops: It is vital for growers to maintain a high level of responsible chemical use and efficient crop protection through continued improvement, uptake a new technology and adoption of best practice. Spray drift is not only a risk of susceptible crops, non-target and sensitive areas but also to the future access of certain groups of chemicals. In addition, poor application methods and reduced efficacy contribute to the development of resistance. The DDCGI is committed to responsible chemical use and the stewardship of agricultural chemicals. The DDCGI plans to use funding from this grant towards organising three training and extension days across the region, the focus will be on chemical application best practice, spray drift risk management, understanding the local weather conditions and record keeping compliance. The DDCGI will engage the services of Mary O’Brien Rural Enterprises to deliver these workshops.

The cotton industry spends about $8M on P fertilizers and about $5M of K fertilizers. This indicates the extent of recognised P and K deficiency. It is envisaged that many cotton-growing soils are nearing deficient status, as continual cotton cropping quickly depletes these nutrients. Identification of these soils through soil and plant testing and formulation of improved fertilizer management practices will avoid nutrient deficiencies that reduce the productivity and profitability of cotton cropping.

Inadequate P and K nutrition are responsible for substantial losses of yield and profitability in cotton farming. Deficencies of both nutrients have been linked with the premature senescence syndrome, although confusion arises between the importance and the interactions of these two nutrients.

Previous research has indicated levels of available soil P at which response to P fertilizer is expected and P fertilizer recommendations for maintaining levels of soil P to adequate crop P nutrition. Similarly, research has been conducted on the association between K nutrition and premature. However, the influence of soil sodicity on the P and K nutrition of cotton has now been recognised and a significant effort is required to determine its importance and economic relevance to production.

The cotton simulation model, OZCOT, is an important component of a number of current and future projects. It is a key tool both for exploring cotton crop responses and as a means of extending the outcomes of science into the industry. In this project we aimed to ensure the ongoing maintenance of the model as well as the continued incorporation of new science to improve our capacity to deal with current industry issues.

The project covered three main research components: 1.) exploring varietal differences in determinacy, 2.) exploring the model’s capacity to simulate compensatory growth responses to insect damage, and 3.) implementing a new soil water balance in the model. These areas were identified as being of current high importance by a meeting of researchers associated with the project, including Drs Greg Constable, Lewis Wilson, Mike Bange and Brian Hearn. Ensuring the model’s capability to simulate compensation is important for specific applications but the issues of growth form and soil water extraction are important for the general performance of the model and hence its application to a range of issues.

A complete review and restructure of the model has been undertaken. In addition to meeting existing usage requirements, the restructure has allowed considerable advances to be made towards making the science included in the model readily available to a much wider audience through conforming the model components to CSIRO Plant Industry’s Common Modelling Protocol.

Modifications have been made to the model to allow it to respond to pest damage. Research is underway to refine these modifications with the aim of developing a version of OZCOT that can be linked with EntomoLOGIC to improve pest management decisions and reduce insecticide use.

Coding for the use of the Montieth-Passioura approach in the Ozcot model has been completed is a version of the model using this approach has been developed. Collection of data for validation and for the development of a database of parameters for different soil types has been impared by drought and the reduced plantings of dryland crops.

This is the first study of which we are aware to attempt to derive an objective, quantifiable measure associated with determinacy in cotton. Two indices were developed which were well correlated to the breeders’ field assessment of determinacy, suggesting that they might provide a suitable basis for an index of determinacy. The measure based on rate of decline in nodes above last flower is the simpler of the two for field use.

This project has produced data which confirmed past findings of the robustness of cotton to compensate for levels of insect damage exceeding those of current industry thresholds for Helicoverpa and mirids. We have further quantified cotton’s ability to recover from damage by compiling a significant database of yield outcomes in a variety of single and multiple damage situations across a wide range of agronomic conditions (i.e. cultivar, plant density, N and Pix application) and in a number of regions from northern Australia to Queensland and NSW (to assess compensation under diverse climatic regimes). To link artificial damage, which is normally implemented evenly within a row of cotton, with the more patchy damage caused by insects, we assessed the effects of various spatial distributions of damage within a stand on growth and yield.

This project was based on the results of extensive research on fruits, ornamentals, vegetables and cotton (in NSW) in which the effectiveness of petroleum-derived spray oils (PDSOs) on insect and mite pests has been unequivocally demonstrated. Oils kill susceptible pests through suffocation (e.g., mites, thrips, aphids and scales). They also influence the feeding and oviposition behaviour of some pests that are not generally susceptible to suffocation (e.g., Helicoverpa armigera and H. punctigera). This has led to behavioural effects on a very broad range of pests becoming much more important than suffocation, the traditionally accepted mode of action, of a much narrower range of pests. Contemporary PDSOs classed as either horticultural mineral oils or agricultural mineral oils are not toxic and pose no threat to human health or the environment. Their impact on natural enemies is generally negligible and arthropod resistance to PDSOs has not been empirically demonstrated in over 100 years of use.

The Strategic Plan builds on the work undertaken by previous Audit activity since 1997 and is directed at providing data and information that will underpin the monitoring and evaluation of investment by the Australian Government and State and Territory Governments and regional organisations in improved natural resource management.

The National River Contaminants Program is a significant research and development program jointly funded by Land & Water Australia and the Murray-Darling Basin Commission. It expands and builds on the highly successful National Eutrophication Management Program, which concluded in 2000 and provides a broad indication of the scale of the challenges Australia faces in maintaining or restoring landscape health.

ANNUAL REPORT NATIONAL LAND AND WATER RESOURCES AUDIT 2000 - 2001