The objectives of this study were: (i) To study the population dynamics of Heliothis on the Darling Downs and to quantify the significance of the major controlling influences (predators, parasites pathogens, weather and host plant quality) on population changes within the species, and, (ii) To assess the potential for an area-wide management approach to the suppression of Heliothis populations through the identification of ecological bottlenecks and the practical manipulation of the controlling factors.

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This project utilises information from Emerald and other irrigation districts in the State to develop a scheduling system, WATERSCHED, as part of a Cotton Management Decision Program. OBJECTIVES 1. To determine cotton yield response functions to differing levels of irrigation water and nutrients, to enable farmers to make better decisions on use of those input resources. 2. To develop a Cotton Management Decision Program which provides commercially relevant options of water scheduling and fertiliser application for extension officers, consultants and cotton growers, to optimise crop profitability. To increase the adoption by farmers of beneficial water management and fertiliser practices.

The objective of this project was to evaluate preliminary and advanced breeding selections from the Narrabri and Biloela programs at up to five locations in Queensland. Over the period 1986/87 to 1988/89 this project played a vital role in selecting new cotton varieties for commercial production. Hundreds of lines from the Biloela and Narrabri breeding programs were evaluated in preliminary trials at Emerald, Biloela and Brookstead, while advanced material was tested in the Australian Cotton Cultivar Trials at these sites plus Theodore.

AIMS 1. To determine the mechanical and physical consequences of land preparation and harvesting on the soils and to relate these effects to soil water content. 2. To develop and assess methods for ameliorating undesirable physical conditions in heavy clay soils. 3. To develop and assess methods for predicting and classifying clay soils with relation to susceptibility to deformation, consolidation and shear under load during cultivation and harvest.

ABSTRACT: When searchinq for an ideal mass screening technique for cotton plant antibiotic resistance to Helicoverpa spp., a 48 hour feeding on squares using final instar larvae bioassay was found to be the most suitable. It correlated better, than the techniques trialed, with the Standard larval bioassay traditionally used as an antibiotic resistance measurinq tool and was more energy efficient than the 'Standard'. An ideal mass screening technique usinq the two spotted mite (Tetranychus urticae} on cotton seedlings failed to correlate with the 'Standard1 rendering it unsuitable for measuring antibiotic resistance to Helicoverpa spp . ...The widely reported finding that gossypols are very important to the antibiotic activity against the cotton bollworm (Helicoverpa arnigera was supported with highly significant correlations between gossypol content of plant material and percent larval weight gains. In contrast, condensed tannin content of 'fresh plant' diet incurred insignificant antibiotic activity against the cotton bollworm but important antibiotic activity against the two spotted mite (Tetranychus urticae).

Objective: Instigate research into application strategies for Pix on cotton in Australia and compare results with similar experiments from California. Of particular interest was the recent discovery that multiple applications of Pix gave superior yield results compared with a single application.

Objective of Research Project: To provide growers with knowledge of the workings and relative merits of available marketing options by making them aware of each marketing methods' revenue potential and income stability. * Extent to which project objectives have been achieved: Given the results and the wide exposure they received when they were published in The Australian Cottongrower, it appears that the project objectives have been achieved. *Research Results: It was concluded that no single marketing strategy would have returned significantly higher returns over the 1973-74 to 1987-88 period. Hence, the focus of the study became the price stability or risk characteristics of each alternative. The results indicated that a grower can trade off the costs of hedging through the call pool option provided by processors against the reduction in price risk that hedging provides compared to the alternative selling methods studied. This is because the basis risk faced when hedging is typically less than the price risk faced in the cash market In addition, it was concluded that yield variability must be taken into account when deciding on a marketing strategy. In certain circumstances, significant crop losses may expose the grower to additional financial loss.

Our objective was to undertake a collaborative research study to identify and investigate problems associated with the perceived "poor adoption rate of Siratac, and develop an action plan and advisory programme to significantly improve adoption