Transgenic Bt (Ingard) cotton has been the biggest step achieved so farm reducing insecticide applications to cotton in Australia. In the past two years there has been a 50% reduction in applications of insecticide to Helicoverpa on Ingard compared with conventional cotton (Long et al 1997). The reduction in sprays has been especially so with endosulfan in the early part of the cropping season when Bt production and efficacy of Ingard plants has been best. The technology has disappointed many growers because of marginal and variable efficacy. Although the full reasons for variability are not well understood, better efficacy is required to continue advances in non-chemical pest control over a greater area

In his paper to you, Mike Logan, our youngest Cotton Australia Board Director, said to you, &quote;unless we have the support of the local communities, we are doomed to extinction&quote;. To that I would like to add that unless we effectively police ourselves as an industry through complete adoption and adherence to best management practice, then environmental agencies, water regulatory bodies and ultimately some consumers led by green activists, will all combine to convert this industry from the profitable, economic driver of much of the bush in NSW and QLD to a marginal one

Microbial damage to raw cotton, sometimes referred to as weathering damage, is a common event in most parts of the world. Microbes, viz. bacteria and fungi, are omnipresent in the environment. In the case of cotton production, microbes form an essential part of the biology and health of the soil in which the cotton plants grow. After the opening of the boll, wind-blown dust and soil components are deposited on the cotton fibres, carrying with them various bacteria and fungi. Thus the microorganisms are always present and only require favourable conditions for their growth. Ideal conditions occur when rain delays the harvest.

Precision Agriculture (PA) involves the management of sites or regions within a field based on local requirements rather than field average requirements. Historical best management practice involves the careful determination of best average treatment for a whole field or farm. Where there is significant variability in the resources to which management is being employed within a field, &quote;best&quote; management must also be varied in order to accommodate local peculiarities. While awareness of within-field variability is not a recent phenomenon, the ability to accurately locate (using DGPS) and revisit sites in a field, for the purpose of conducting useful quantitative measurements or treatments is only a recent development. On-picker real-time yield monitors provide the opportunity to accurately measure cottonseed yield each second during picking. When this yield information is linked to a geographic location a yield map may be produced giving the grower or agronomist quantitative data for use in evaluating the degree of variability in a field.

Conventional plant breeding has done much to improve cotton's tolerance to pests and diseases. However, fungal diseases such as Verticillium and Fusarium wilts remain important factors minting yield under certain environmental conditions. In particular, the increasing spread of an aggressive strain of Fusarium wilt in cotton-growing areas is causing growers concern. As yet, no genes providing immunity to the vascular wilt diseases have been identified in cotton. Conventional breeding has been used successfully to generate cotton cultivars with good fungal tolerance. However, tilts tolerance can still be improved and we see the use of transgene-derived antifungal proteins for enhanced host plant tolerance as an important adjunct to the development of cultivars by conventional breeding methods. Our goal is to identify genes that confer improved tolerance to wilt diseases and express these genes in transgenic cotton lines.

Commercial cotton crops throughout NSW have been surveyed in November and March of each season since 1983 to determine disease distribution, incidence and severity. Cropping history, field preparation, seed rate, plant stand and the amount of crop residue remaining from the previous cotton crop have been recorded for each field inspected. Between 80 and 100 commercial fields have been inspected in each survey. The results of these surveys provide a basis for prioritising research efforts and give an indication of the impact of farm management practices on disease incidence and severity.

In a broad sense, biocontrol can be defined as the manipulation of a root or soil environment, through non-chemical means, to reduce the activity of pathogens. This broad definition includes the use of resistant cultivars, cultural practices and the introduction of beneficial microorganisms into the root zone. The cotton disease biocontrol program at the Australian Cotton Research Institute focuses on the use of beneficial microorganisms to control cotton diseases. Several naturally occurring bacteria are antagonistic to pathogens. These bacteria are referred to as biocontrol agents. When introduced into the root zone, the biocontrol agents can interfere with the activity of the pathogens.

It hardly needs to be said that the supply of irrigation water is a major issue for the industry and a major hint to production, and that there are economic and environmental dimensions to the debate about water, which is characterised more by rhetoric than fact. For example, we have heard. .... &quote;The cotton industry has a veracious appetite for water&quote; - &quote;You and I know 6Ml/ha is not enough to water a successful cotton crop&quote;. One assertion relates to the industry as a whole and the other to the operation of a farm, so providing a convenient introduction to two questions addressed in this paper. .. How much water does the industry actually use? and How much water does a cotton crop need?

Fungal diseases such as Verticillium Wilt, Fusarium wilt and black root rot cause appreciable losses to the Australian cotton industry, particularly in years when environmental conditions favour disease. Research in our group is focussed on genetic engineering approaches to increase the resistance of cotton to fungal attack

The silverleaf whitefly (SLW) Bemisia tabaci B-biotype is a major problem to cotton growers overseas and is a threat to the cotton industry in Australia. It is currently established in plant nurseries in most states and is a pest of various horticultural crops in the field in North Queensland. The genetically modified INGARD cotton contains a Bt gene which codes for an endotoxin that is active against major lepidopteran pests such as Helicoverpa spp. Bt cotton has been trailed in Australia over the last few years with some positive results (D. Murray pers. comm. ). However, the key to the success of transgenic cotton will be to integrate it with other management strategies, such as crop refuges, in an effort to slow resistance development (Fitt 1996). Pigeon pea is highly preferred by Helicoverpa spp. and is being used as a refuge or trap crop (Walker et al 1998). Lucerne is also being investigated as a refuge or breeding ground for beneficial insects (Mensah & Singleton 1998; Walker et al 1998), such as predators or parasites of Helicoverpa spp. Sowthistle, a common weed in cotton agro ecosystems, may also act as a refuge for beneficial insects or for the pests themselves. Cotton and lucerne are both hosts of the SLW overseas. These and other plants in the cotton agro ecosystem may become important hosts in Australia. This project assessed the suitability of these key hosts to SLW development.