To quantify and explain patterns of soil compaction caused by cotton pickers and to develop a set of practical recommendations for minimising soil damage during harvesting operations.

Evaporation losses during sprinkler irrigation are perceived by the irrigation community to be high and is a major impediment to the adoption of sprinkler irrigation. Previous overseas experimental studies have reported losses up to 45% of the applied water and that a large proportion of the loss is droplet evaporation. However, a recent field experimental study conducted over a cotton crop at the University of Southern Queensland showed that the total evaporation is low (about 8%) and that droplet evaporation would be less than 1%. The additional evaporation during sprinkler irrigation would be about 4% of the applied water.

Energy costs have risen significantly over the past decade and cotton growers continue to look for ways to improve their on farm energy use efficiency. Pumping costs on irrigated cotton farms consistently account for 60 to 70% of total energy consumption on farm (Baillie and Chen 2008). The National Centre for Engineering in Agriculture (NCEA) has developed a Pump Efficiency Monitor (PEM) to assess energy consumption by the large mixed flow pumps found across the Australian Cotton industry. The ability of the Pump Efficiency Monitor (PEM) to continuously record pump station parameters provides data to assess combined motor and pump efficiency over an entire pumping event. This project highlights the importance to test each individual pumping set-up to identify the optimum operating point to achieve maximum efficiency. Significant cost savings are possible for individual growers and the industry collectively.

The Problem Silverleaf whitefly is costly to manage. Understanding the factors that help control whitefly populations is valuable in preventing and managing outbreaks to reduce the risk of costly sprays and of lint contamination. In experiments over 3 years we followed the survival of whitefly eggs and nymphs in the field and attributed mortality to: parasitism, predation, dead or missing. This allows us to understand both the magnitude of natural mortality and also start to identify the main factors causing it.

Issue being addressed Peak summer weather in the central Highlands region can be highly variable with potential for cloudy wet monsoonal influences or high temperatures and humidity which reduces a crops capacity to keep cool. We are investigating tactics to enable substantially earlier planting and crop development to reduce crop exposure during boll filling to mid to late summer conditions. This may improve the management of climatic risk for cotton production in the Central Highlands environment and lift aggregate yield potential and lint quality.

Contamination is the major issue of concern to the ginning, and textile industry. In our study cottons with and without foreign matter were processed into yarn. The cotton was carded but the contamination was not fully firmed by the card as foreign matter often flattened in carding. The contamination tends to fibrillate and behave as coarse fibers. The contaminated cottons fiber always appears to interfere with the drafting process and the ring travelers during yarn formation resulting in increased end breaks, thus lowering the strength of contaminated yarns

The Problem Periodically, late season outbreaks of pests such as thrips, jassids, cluster caterpillar and spur-throated locusts may cause damage to the cotton canopy and/ or flowers. Research over 4 years investigated potential consequences for cotton by manually removing all leaves from the top 6 or 9 nodes at different dates from flowering to beyond cutout or removing 50 or 100% of leaf area. We also evaluated flower loss for a 1 week period to test if this interacted with leaf damage

In 2001 a comprehensive review of centre pivot and lateral move (CPLM) irrigation systems in the Australian cotton industry was undertaken by Foley & Raine (2001). Interviews of 31 growers provided a detailed look at the design, management and performance of these systems. Although there is no definitive information on the total number of irrigators using CPLM in the cotton industry, it is apparent that since this study, the number of CPLM systems used within the cotton industry has significantly increased. With the accelerated adoption under infrastructure funding programs has come more questions surrounding design, operation and management.

A major threat to the longevity of Bt cotton is Helicoverpa's ability to develop genetic resistance to high doses of Bt toxins. To counter this threat, refuges are planted to produce large numbers of moths to dilute any moths emerging from Bt crops which could be carrying Bt resistant genes. Using cages (Fig. 1), we compared the number of moths emerging from Bt cotton and productive refuges and their levels of resistance.

In the Australian cotton industry nutrition is a significant cost with 75% of irrigated cotton respondents to the 2012-13 grower practice survey spending between $300 and $600 per hectare on nutritional inputs for their 2012-13 cotton crop (Anon, 2013). Within nutrition expenditure nitrogen (N) is the most significant input however, nitrogenous fertiliser use has increased to the point where significantly more is being applied in commercial crops than is recommended as part of industry best practice. This additional N is a significant additional cost to growers that can equate to many thousands of dollars spent that does not always result in lint yield increases. The Regional Development Officers (RDO) initiated N trials as a means of gaining an understanding of how N fertiliser management influences Nitrogen Fertiliser Use Efficiency (NFUE) as a simple tool to review crop performance