The cost-benefit analysis of 43 fields of cotton defoliated using at least one pass with variable rate chemical application, showed significant benefits for the farmers involved. The average savings in chemicals when compared to what would otherwise have been applied was $11.82/ha. The farmer was able to save, on average, 25% of his chemical bill. In most situations this savings in chemicals more than covered the cost of the Belt-Wide Agriculture service ($10/ha) and left around $4.23/ha in the farmers pocket.

High temperature stress adversely affects cotton growth and development. This paper presents preliminary results of studies evaluating methodologies that measure the ability of cotton to tolerate high temperatures. Simple methodologies that measure cell damage and loss of enzymatic function are being employed to measure the tolerance of cotton cultivars to high temperatures. Early results suggest that there is some variation among cultivars in their ability to withstand high temperatures under laboratory conditions. These methodologies will be further evaluated to establish their value in identifying thermotolerant cotton cultivars for potential use in cotton breeding programs

Northern Australian regions could become significant cotton producers in the future if regulatory issues and negative industry perceptions can be overcome (Yeates 2001). In Western Australia, significant production-based research has been conducted at Kununurra and Broome in order to evaluate the feasibility of a winter cropping strategy for cotton. Sustainability has been a focus of research and the development of a RMP for Bollgard II is an essential prerequisite to obtaining regulatory approval. For seven years, between 1997 and 2003, a range of crops was assessed for their usefulness as refuge crops in a future Ord Stage 2 cotton industry and a draft RMP produced.

Magnet is a blend of synthetic plant volatiles that attracts Helicoverpa moths, especially females. Currently, research is determining strategies to utilize this product in cotton pest management. One strategy is to mix Magnet with synthetic insecticides and use the product as attract and kill (Pyke et al. 1987) on Bollgard ) cotton to reduce Helicoverpa populations on adjacent conventional cotton crops. The study reported here showed that, Magnet mixed with insecticide and applied to Bollgard cotton crops, can reduce populations of Helicoverpa spp. on adjacent conventional cotton crops. The study also showed that using Magnet in this way, growers could reduce insecticide use and costs for control of Helicoverpa spp. on conventional cotton crops

Here we report on the on-going investigation into mirid damage assessment in Bollgard II with the objective to determine action thresholds for mirids at different stages of Bollgard II growth in irrigated and raingrown systems.

In Australia, problems with mirids, Creontiades spp. have increased substantially following the adoption of Bollgard II. According to Cotton Consultants Association (CCA) 2005-06 season survey, over this past cotton season two to four insecticide sprays were required to manage mirids. Unlike conventional cotton, in Bollgard II mirids are causing damage from seedling through to late boll formation stage (Khan and Bauer 2001; Lei et al. 2002) and require management intervention throughout the season. Integrated pest management (IPM) is becoming a popular management approach for mirids in the Australian Cotton Industry. With the IPM approach, insecticides are not excluded as a management option; instead judicious application of insecticides is encouraged to maximise use of beneficial arthropods in cotton fields. In Australian cotton, IPM options for sucking pests include the use of reduced rates of insecticides and use of adjuvants/additives with insecticides to obtain greater benefit. The adjuvants/additives used in Australian cotton include table salt (NaCl) and petroleum spray oil (PSO). Several studies have investigated salt mixture with insecticide against green vegetable bug, Nezara viridula (GVB) and mirids in cotton in Australia (Khan et al. 2002; Khan 2003; Khan and Murray 2004). When salt is mixed with reduced rates of insecticides, efficacy is enhanced and is equivalent to the full rate of the chemical alone. However, information on the rate of salt mixed with chemical was not clear cut. Some confusion has arisen since salt is used in pulse crops at 5 g/L of water while the cotton use rate is 10 g/L of water. It was therefore necessary to clarify this issue. The objective of this study was to determine the optimum rate of salt mixed with reduced rates of chemical to obtain maximum mortality of target pests with minimum disruption to the beneficial arthropods in cotton.

The survey was a pilot study as a precursor for an industry wide survey to be conducted in the coming season. Below are the results of the study. Because of the small sample size and non-independent nature of the data collected (the same individuals provided information on more than one spray event) statistical analysis of these results is difficult. Nevertheless the results indicate some interesting trends.

Targeting the last generation of Helicoverpa armigera that typically escape cotton fields prior to pupae busting with the use of summer trap crops has been an integral component of the central Queensland Bt resistance management strategy. A superior method for targeting these escapes might be to use area-wide applications of the attract and kill product Magnet on late season cotton fields. Experiments that aimed to assess the potential efficacy of area-wide applications of Magnet laced with insecticide for Helicoverpa moth control in the Dawson Valley suggest considerable potential for such a strategy with significant reductions in Helicoverpa being recorded after each application. Further experimentation to test the validity of area wide Magnet applications as an alternative strategy to trap cropping will be conducted during the 2006/07 season. This paper outlines the progress of the research to date.

The last 23 years has involved both major change and subtle fine tuning of strategies taken by the Australian Cotton Industry in managing insecticide resistance in the cotton bollworm, Helicoverpa armigera. Early strategies linked chemical use across multiple crops and involved window restrictions focussing on pyrethroids and endosulfan. After 10 years the strategy retained a focus on cotton only, and the LepTon test kit allowed for specifically targeting H. punctigera populations which remained susceptible to pyrethroids. More recently integrated pest management (IPM) practises and the registration of numerous 'soft' chemistries with greater specificity have provided for less restrictive guidelines on chemical use, with beneficial preservation as a tool for minimising spray events and predating resistant survivors considered as part of the strategy.

Many insect natural enemies are omnivorous, in that they include extra-floral nectar, floral nectar, honeydew and pollen, as well their insect prey in their diet for at least part of their life. Access to these plant-based foods can reduce pest pressure by increasing both the individual 'performance' and local density of natural enemies. Commercial 'food sprays' that are rich in carbohydrates and proteins, such as Amino-Feed and Envirofeast, can be applied to cotton crops to act as artificial plant-based foods. *We examine the extent to which Amino-Feed and Amino-Feed UV benefit a predator, the Pacific damsel bug, and a pupal parasitoid, the banded caterpillar parasite. These insects are important natural enemies of heliothis. *The provision of either wet or dry residues of Amino-Feed UV had no discernible effect on Pacific damsel bug survival and development rates. *In contrast, the provision of artificial nectar, cotton extrafloral nectar and Amino-Feed (plus extrafloral nectar) had a marked effect on banded caterpillar parasite longevity. Whilst fed female parasitoids lived longer, the total number of eggs they laid was unaffected by diet. This is because females exhausted their maximum egg supply around the same time across all treatments, and death occurred shortly thereafter in the water control treatment but after considerably longer in the other diets. Because females of the banded caterpillar parasite were also able to feed on small amounts of host body fluid, this alternative source of nutrition best explains why there was no effect of diet on fecundity (i.e., the number of eggs laid). *It is likely that providing natural enemies with a supplementary source of food will be more important during periods of prey/host scarcity or absence. Thus, from the perspective of integrated pest management, artificial and natural plant-based foods are worthy of further investigation because they have potential to improve the ecosystem service of biological pest control.