Raingrown cotton in Northwest NSW and Southwest Queensland is not grown on metre beds, rarely has aerial applications, relies to a large extent on stored water, uses little or no fertiliser and large areas are harvested with brush strippers. Whilst this production system seems a far cry from its irrigated cousin, the production costs and returns on a per bale basis are similar. Since the early 1980's raingrown cotton has grown from a fledging industry to become established as a reliable dryland summer crop. Dryland cotton producers now possess cotton specific planters, cultivators, spray rigs and harvesters. They have adopted management practices to ensure returns in all but the toughest of seasons. They forward sell cotton using innovative marketing tools. Only a major reduction in the price of cotton or a strong recovery in grain prices will see the expansion of dry land cotton stifled.

This paper looks at some of the differences between raingrown and irrigated cotton in Central Queensland, in particular: differences in basic inputs and differences between major problem areas. The important management practices and the research needs of the raingrown crop in Central Queensland are also briefly discussed.

The Australian cotton industry relies heavily on chemical pesticides for management of a diverse array of pest insects, weeds and diseases. Pesticide use is a major economic and environmental liability for the industry and all measures to reduce this dependence need to be taken. The bacterial pathogen of Helicoverpa, Bacillus thuringiensis (Bt) is one avenue for reducing the use of conventional chemicals. Bt produces a series of endotoxins which are highly specific for particular insect groups and is thus ideally suited as an environmentally friendly pest control agent. One Bt strain is toxic to Lepidoptera and is being increasingly used for Helicoverpa control in cotton. Many chemical companies are investing heavily to produce efficiacious, reliable and cost effective Bt products and their use is likely to increase dramatically over the next decade. Coincident with this change the industry will see the release of genetically engineered cotton varieties which have been transformed to produce the delta endotoxin from Bt, making them highly resistant to feeding by Helicoverpa larvae.

The genetic material (DNA) of living organisms is structurally the same whether it is found in humans, plants, fungi or bacteria. This fact enables the genetic engineer to use molecular genetic techniques to transfer genes from one species to another and so produce, for example, transgenic cotton plants expressing bacterial genes for novel characteristics such as herbicide and insect resistance. This fact also makes it possible to universally employ related techniques to help in the genetic identification of individual people, varieties or strains in human, plant or microbial populations. Thus, the methods used in the compilation of human genetic fingerprints for the identification of people in immigration, forensic and criminal cases could equally be used to differentiate between plant species, cultivars and progeny in plant breeding programs, to identify the particular pathogen strain in an outbreak of plant disease, or to characterise the varieties of mycorrhizal fungi in an agricultural field. The sensitivity of such techniques rests in their ability to detect the rare or subtle differences that exist between the genes of one individual and another.

Traditional plant breeding techniques have had a major impact on the Australian cotton industry through the production of the widely successful CSIRO varieties Siokra and Sicala. This science will continue to provide the Industry with the most relevant varieties for Australia's unique environmental conditions, but now it will be enhanced by the new technology of genetic engineering. Breeders in the past have been very restricted in the genetic resources that they can call upon for variety improvement and have only been able to produce new re assortments of genes already present in existing cotton varieties, or at most their very close wild relatives. Potentially useful genetic resources present in other plants or even non-plants have been inaccessible because of the sexual barriers to crossing between unrelated species. This genetic resource has now become accessible because of recent advances in recombinant DNA technology, the science of studying and manipulating genetic material. It is now possible to produce transgenic organisms, organisms containing genetic material from novel sources. The technology has been used in a variety of organisms from simple bacteria, yeasts and fungi, up to more complex organisms such as plants and even animals. The techniques have recently been extended to cultivated cotton, opening up tremendous possibilities for the improvement of our existing Australian cotton varieties.

Outbreaks of native budworm, Helicoverpa punctigera, often arise after egg laying by emigrant moths from distant populations. We would be in a better position to control this pest if (i) we could find genetic differences among populations allowing identification of moth origins, and (ii) if we understood the nature and extent of heritable regional differences for ecologically important traits. Towards this end we looked for genetic differences among moth populations originating from widespread Australian sites.

The insecticide, endosulfan, is still an effective weapon in the arsenal against Hellothis pest species. It fs used extensively in spring and summer as a cheap alternative to the synthetic pyrethroids. This is despite the recurrence of endosulfan resistance first observed in the 1970's (Kay et aL 1983). According to the monitoring data obtained by Neil Forrester ( 1992), NSW Agriculture & Fisher1es, endosulfan resistance was present at levels of 10- 30% in the Namoi Valley during years 1986-1989. However, in the past two years resistance has undergone a sudden increase, with frequencies of up to 50% during summer. A similar pattern was observed in Emerald, although resistance frequencies are higher than in the Namoi Valley (Forrester 1992).

The Cotton Research and Development corporation (CRDC) is funding a comprehensive 3-year project to discover the environmental fate of endosulfan sprayed on cotton for insect control. Experience overseas suggests that endosulfan is in quite a different class to organochlorines like DDT, rarely if ever accumulating in soils or flora and fauna. However, apart from the routine testing performed by the manufacturers, there was no independent data on the fate of endosulf an under Australian conditions. This project was funded by CRDC to overcome this lack of data.

The suspected importance of pyrethroid metabolism in resistant H.armigera. made the investigation the biochemical basis of pyrethroid resistance in H. armigera imperative. In this background paper, we summarise our findings.

It has been 9 years now since the introduction of the Summer Crop Resistance Management Strategy in 1983/84 season. This voluntary Strategy has been well accepted by all segments of the industry and has underpinned the development of the thriving rural success story that is the Australian cotton industry.