The Silverleaf whitefly (SLW), Bemisia tabaci Biotype B is a major production constraint in many parts of the world including the USA, Israel and other parts of the Middle East. Legumes, particularly soybean, have been virtually eliminated from many production systems in Texas and Arizona where SLW is now endemic. Cotton growers in the USA (Arizona) are faced with potential losses of up to $500 million annually, directly and indirectly from SLW. SLW was first discovered in Australia in 1994 by Dr. Robin Gunning (NSW department of Agriculture). Research by CSIRO scientists has since shown that it has spread throughout much of the east coast of Queensland and is now the dominant whitefly on both cultivated and wild host plants in the northern half of Australia. SLW has since become a troublesome pest of horticulture with frequent outbreaks in the Bower/Burdekin region and other coastal regions of Queensland and New South Wales. The spread of SLW into the central Queensland (CQ) cropping areas of Emerald and the Callide and Dawson valleys presents a serious and imminent threat to field crops including sunflower, peanut, grain legumes and cotton in these areas and other cropping regions further south.

Earlier maturity in cotton would counteract increasing production costs and facilitate the expansion of cotton production into areas with shorter growing seasons. Gaining earlier maturity without some yield penalty is difficult to achieve. Ultra-narrow row (UNR) cotton, a production system with rows spaced less than 40 cm apart, has shown potential for earlier maturity than conventionality spaced cotton (1m apart), without substantial yield penalties. In practice, this earlier maturity has been difficult to achieve consistently in UNR trials in both Australia and the United States. Information on the growth and development of UNR cotton is needed to find out why. A trial in southwest NSW near Hillston compared cotton in ultra-narrow (25 cm row spacing) and conventionality spaced rows. Despite greater dry weight and fruit production in UNR earlier in the season, the competition for light and resources later in crop development negated these early benefits and did riot translate into either earlier maturity or any increase in crop yield. The structure of the UNR cotton canopy meant that light was not penetrating through the top part of the plant to bolls lower in the canopy, perhaps delaying maturity. Studies are continuing into a greater range of environments and different population densities to further understand the key physiological processes of UNR production in order to optimise the system

Previous studies of soil used for cotton production has highlighted that soil structural decline may be a potentially one of the limiting factor restricting cotton growth (CRDC report MCK IC & MCK 2C). Surface soil aggregates of soil used for cotton production will slake and/or disperse in water. The implications vary according to the scale at which this phenomenon occurs. Generally slaking is a desirable process in terms of surface soil structural regeneration, a process termed self-mulching. If slaking is excessive, resulting in aggregates < 100 pin in diameter, there is a chance that a temporary surface crust may form (Loch, 1995). Further, if the slaked aggregates disintegrate to producing sand, silt and clay, an undesirable massive structure may result. Water and air movement, root penetration and function, and seedling establishment often are affected adversely (Field, 2001). In order to identify the potential for surface soil structural decline two soil stability procedures have been identified by the industry. One of the procedures is termed the aggregate stability in water test (ASWAD, developed by Field et al. (1997), which is a diagnostic procedure used to assesses the degree of dispersion aggregates experience when immersed in water. The advantage of the test is it requires little specialised equipment, is relatively expedient making it satisfactory for routine use by land managers in the field or at home. Consequently the ASWAT procedure has been incorporated into SOILpak for cotton growers (3&#39rd edition) making it accessible to workers in the cotton industry. The other procedure identified by industry is a modified end-over-end technique. This procedure is used to assess the rate at which surface soil slakes and/or disperses. By comparing these surface soil breakdown dynamics it is possible to assess the potential for a surface crust to form.

Soil type and climate both influence the cotton plants response to soil moisture status. Soil types differ in both the amount of moisture contained and more importantly how this moisture is available to the plant. Climate, through evaporative demand, influences plants requirement for water, mainly through changing evapotranspiration rates. The combination of these two factors has a large effect on the level of plant moisture stress and consequently irrigation scheduling for cotton. Our research investigates the effect of these factors on the cotton plant in the Australian cotton industry and our aim is to refine irrigation scheduling guidelines and promote increased water use efficiency

Our research addresses three questionsI. Is soil biodiversity reduced in agricultural soil compared with undisturbed soilsΓ2. Does cropping affect which groups of fungi are present in agricultural soilsΓ3. Do microbes increase carbon stored in soilΓ

The natural resources (including land and water) of this planet are not inexhaustible, and therefore require continual management for them to remain sustainable. However, the demand imposed upon these resources is huge and increasing on a scale more than natural cycles can replenish. Thus the sustainability and the management of these resources are vital for the survival of all living things, including the human race. Management of these resources require knowledge and information about them. In Australia and worldwide the importance of updating regional land resource maps has come to the forefront of many government and non-government organizations (Bui and Moran, 2001). This is due to increased awareness of environmental impact of land use and the fact that land is an important component of the agro-ecosystems, which needs to be conserved for the future generations. Knowledge of land feature distribution over large areas has become increasingly more important for numerous scientific and policy purposes (Cihlar et al. 2000). Digital land feature mapping can thus greatly increase the ease of which needed soil and land information can be assessed and applied to land use planning and resource management

Final Report - Digital soil mapping available water content in the Lower Macquarie Valley, NSW

FR

There is evidence the nep and short fibre content of Australian cotton is too high compared with other growths of similar quality1. These characteristics are a result of the productive and efficient harvest and ginning practices utilized by the Australian industry but the problem is exacerbated by current lint cleaner design. In particular, the combination of lint cleaner elements, i.e. the feed rollers and feed bar, grid bars and the doffing brush around the lintcleaner saw, and the transfer ratios between these elements affect fibre quality. The broad aim of this project was to adapt and re-engineer the widely used fixed batt saw lint cleaner to reduce short fibre and nep content. The main adaption proposed at the start of this project was an auto-levelling system for the lint cleaner feed such that the weight of fibre transferred onto the saw would always be constant. Typically the unit is powered by a single30kW motor, which regardless of the rate of fibre flow runs at full speed.Currently in lint cleaners there are no sensors to regulate fibre flow or draft settings. Excessive speed and large draft or combing ratios, i.e. a high saw surface speed to feed roller speed, increase damage to the lint. Implementing an auto-levelling system requires sensors and variable speed devices to maintain a consistent flow of material. It has been shown in previous work2 that low combing ratios reduced short fibre content and improved fibre lengthand length uniformity. Introducing constancy to the batt weight requires a greater degree of control of this combing ratio effect. Thus, the initial focus in this project was to test the possibility of sensor control of mechanical elements, in particular the feed mechanism, in the standard fixed batt saw lint cleaner and CSIRO's Modified Lint Cleaner (MLC). As well as testing fibre and batt weight variation through the lint cleaner machine, work also concentrated on the application of additional mechanical elements, e.g. a combed grid bar heel, designed to even the transfer of fibre onto the saw.Once achieved, the objective was then to link this mechanical control to moisture control systems being developed as part of New Ginning Technology for Australian Cotton: Part II (Moisture & Contamination) project. However, observations from flow and mass sensors applied to a commercial gin in the firstyear of the project, showed the delivery of fibre from the gin by the current system was too fast and too uneven to be controlled. Work on the project subsequently defaulted to proving and extending the veracity of the MLC to industry, with a view to commercialising the MLC technology.Alternate fibre conveyor designs to give a more even feed and allow time for the batt to be levelled and humidified were drawn up towards the end of this project. These designs require greater intervention to the ginning system than was originally foreseen in this project. A new project around these designs was proposed to the CRDC in a FRP in January 2009.

Final report to National Lippia Working Group steering committee and funding partners for the National Lippia Best Practice manual