Scepticism on the applicability of models is not due to their rarity nor lack of exposure. A recent survey of models targeted at farm production and catchment management (Hook, 1997) recorded over 90 models or computerised decision support systems (DSS) developed and/or supported in Australia. The compilation included models relevant to the cotton industry, the OZCOT and CBRCOT cotton models and the now defunct STRATAC DSS. It would be safe to assume that there are probably runny more such products than those listed in this report. Yet, in Australia (Cooke, 1994) and world-wide (Plant, 1997), farmer acceptance of models and decision support systems has been disappointingly low. In this paper, our objective is to relate our experiences of how some farmers and consultants have benefited from the application of systems models in their farming operations. We argue that this recent effort in applying models within industry has important distinguishing features from past efforts on decision support systems and that the current market pull for commercial access to systems models may be sustainable. We conclude with proposed plans to progress towards commercial delivery of systems simulation to farmers in the northern cropping region

Residues of agricultural chemicals in soil and run-off water are a major cause for concern in cotton production. Microorganisms are known to be important in residue degradation but the role of soil fauna in this process has received much less attention. In some cotton-growing soils the Collembolan, Proisotoma minuta, is a predominant species and may contribute to residue reduction. The effect of herbicides used in cotton-producing areas on P. minuta is being examined to determine whether residues are likely to be metabolised by the insect.

Dryland cotton production is an important component of cropping systems in the northern grain belt. It has been a difficult crop for many growers to integrate into their existing cropping systems because of its high soil water usage, narrow planting window, long growth period, and high pesticide inputs, to name just a few factors. A number of cotton industry research projects have commenced in the last 5 years to look at different aspects of dryland cotton cropping systems. This work, in conjunction with the practical experiences of many growers who have been developing conservation farming systems over the last decade is providing some clear guidelines towards the development of sustainable cropping systems and best management practice for this section of the industry.

The commercial release in Australia, in 1996, of transgenic cotton containing the Cry1Ac gene of Bacillus thruingiensis Berliner var. Kurstaki (Bt), was a significant step towards reducing the use of conventional pesticides on cotton crops, for the control of Helicoverpa armigera. It is possible, however, that H. armigera could develop resistance to the Bt toxin, as has occurred with the use of other insecticides. The seasonal variations in the efficacy of Bt transgenic cotton, reported from field trials (Fitt et al 1994), could exacerbate the development of resistance (Daly, 1994), so there is a need for these variations to be better understood.

Cotton leaf roll dwarf virus (the causal agent of Cotton blue disease) or a virus closely related to this species was detected in an asymptomatic Sea Island cotton plant (Gossypium barbadense) in Laivai, Timor Leste.

Precision agriculture (PA) as a crop management philosophy was first hypothesised in the early 1990's as a way of utilising the development of technology such as the Global Positioning System (GPS) and variable-rate crop applicators to produce crops in a more sustainable fashion. Historically, fields have been managed as homogeneous units, receiving equal amounts of crop production inputs. The rational behind precision agriculture, or site-specific crop management, is that by identifying within-field variability in crop and soil attributes (e. g. cotton yield, soil nitrogen levels) and their origin, it then becomes possible to optimise crop production inputs such as pesticides and fertilisers on a point-by-point basis. Implicitly, this lowers the potential for the over and under-application of these crop production inputs, thus increasing profitability for the grower whilst simultaneously reducing the probability of adverse environmental impacts such as groundwater or surface water contamination from the over application of agrochemicals. While progress in developing a filmy integrated PA system has been slow over the past decade, research from a number of industries worldwide has highlighted there will be many benefits to be galled from adopting such a system. Secondly, triller technological advances in airborne imagery collection, on the-go sensor development and computer processing techniques means there is an unprecedented number of tools available to aid in crop management. Furthermore over the last decade it has emerged that each country and crop will its own unique requirements within the larger framework of PA.

Cotton fibres, or lint, are very long single cells containing almost pure cellulose. The fibres develop in the weeks after flowering from single cells on the surface of the young seed. Each fibre cell is single at first but elongates and develops rapidly, eventually forming the mature cotton fibre. These processes require the ordered expression of genes which mate enzymes, structural proteins and signalling molecules that together determine the properties of the fibre. Domestication has modified fibre development to produce cotton varieties with greatly improved fibre length, strength and quality. However, the selection and breeding of plants with desirable fibre characteristics is slow and expensive. As such, future crop improvement is likely to depend upon genetic engineering and the cotton industry has been a leader in research and commercialisation of transgene technology, with momentous consequences for the agronomic properties of the crop such as insect and herbicide resistance. Whilst fibre improvement has not been the initial focus of the application of DNA technology, research to this end has been vastly accelerated in the last decade, particularly in the USA. The recent formation of the international Cotton Genome initiative between scientists in USA, France and Australia represents a global effort to develop a saturated and fully integrated genetic and physical map of the cotton genome. Gene discovery is also advancing rapidly, with the release of over 20,000 partial gene sequences (called ESTs) from elongating fibres of both diploid and tetraploid cotton, and the use of CDNA microarrays to facilitate global expression profiling.

White speck neps cause significant financial losses to the textile industry and the following studies look at several factors that may affect white specks. Processing factors, such number of lint cleaners used at the gin, mill card settings, and combing are studied, as well as varietal differences, to see the effect on white specks in the finished fabrics. This paper examines the white speck phenomena as seen in the US and Australian studies. The first study has 4 extreme US varieties that were grown specifically to produce different levels of white specks. In this study, it happens that the tandem card was improperly set during insulation results in much higher levels of white specks than single carding, showing the importance of proper settings and maintenance. The second study looks at 26 US leading varieties studied (LVS) by AMS (Agriculture Marketing Service of the USDA, they measure what are perceived to be the important quality measurements on all cotton produced in the USA). This study also includes five extreme varieties grown in the same field (similar to the first study) and processed identically in the gin and mill. This shady also compares carding with combing. Four varieties from the 26 Leading Variety Study by AMS were carded and combed and the fabrics are analysed for white specks. The final two studies are collaborative studies between US and Australia. The cottons were gown in Australia and the studies compare ring to rotor spinning and different levels of lint cleaning at the gin. The first year used small seed cotton samples (300lbs) and the second year used full modules of seed cotton. Combing was found to reduce the white speck problem, while other processing seems to open and separate the immature fibers spreading the white speck problem. Ultimately we would like to develop strong predictions of white specks from high-speed instruments that test bale fibers, and have the white speck potential included in the classification of cottons.

As with all post mortems the aim is to work out what happened and why. By understanding this we will be better able to address the issue of how much of Australia's cotton will be affected by this pest and what is the level of the threat. A good starting point is the basic set of requirements for a silverleaf whitefly outbreak and here we need to consider the &quote;outbreak pyramid&quote; (Fig. I, modified after Peter Ellsworth, University of Arizona, Maricopa). The two most critical factors are climate and cropping systems, without both of these an outbreak is unlikely.

Helicoverpa spp remain the most important pest in the Australian cotton industry. They are resistant to most of the insecticides used by the industry. The cotton industry is determined to reduce their independence against this pest. As a result there is a strong push by the industry in recent years to adopt a true IPM program in order to minimise insecticide use. Semio (signalling) chemical that may impact on pest behaviour are currently being studied to isolate potential chemicals for efficacy against cotton pests. Chemicals on the leaf surfaces of refuge crops, cotton cultivars and other plant species will be isolated , purified , formulated, bio assayed against cotton pests and the potential ones deployed in cotton IPM. Field and mesh house trials of different plant species and refuge crops have been screened for oviposition and feeding preference against Helicoverpa spp adults and larvae. Results, so far showed that several less preferred crops and plant species deter Helicoverpa ssp. adult oviposition and also cause mortalities in the larvae. An unidentified plant, codenamed &quote;PlantX&quote; was found to reduce Helicoverpa spp. Egg lay by 94 %. The top, middle and base leaves caused 89, 78 and 89 % mortalities respectively to H. punctigera second stage larvae. The seeds also caused 74% mortality to the larvae. Further studies are continuing to extract toxic compounds in PlantX and bioassay it against Helicoverpa spp. If successful a new IPM tool will be developed for cotton growers for use in IPM programs.