Development of sustainable, efficient, integrated weed management systems for cotton production is the primary goal of the weeds programs (CRDC and CRC funded). This goal is being achieved through a range of approaches including determining a base level for weed management in the cotton industry, scientifically evaluating a range of alternative weed management strategies including different herbicide combinations and rates, alternative herbicides with transgenic, herbicide tolerant cotton varieties and alternative cultivation and stubble management practices, and developing specific weed management packages for difficult to control weeds. This project has furthered the weeds goal in all aspects. An important highlight has been the development of a management strategy for nutgrass. Preliminary field evaluation of a range of weed management options including normal and transgenic cotton has also been undertaken. Work over the next 3 years will examine options for peach vine management, and management options with stubble retention.

The objectives of the project were (I) to evaluate potential biocontrol agents for seedling disease control, (2) to evaluate potential biocontrol agents for the control of Verticillium wilt of cotton and (3) to develop and compare strategies for the biocontrol of Verticillium wilt. It was also proposed that some preliminary work would be carried out to investigate the feasibility of biocontrol methods for the control of black root rot, Fu sari um wilt and Galathera syndrome. A major development in the course of the project was the shift in the emphasis from research on biocontrol of Verticillium wilt to that on biocontrol of Fusarium wilt. By the 1995-96 cotton growing season it was clear that the varietal resistance was working effectively against Verticillium wilt. Fusarium wilt, although largely confined to Queensland, was becoming a concern to the NSW and Australian cotton industry.

The results of disease surveys have indicated a declining incidence of Verticillium wilt and seedling diseases and an alarming increase in the prevalence of Fusarium wilt, black root rot and Alternaria leaf spot. Bacterial blight and Alternaria leaf spot have become significant problems for Pima growers in the Bourke area

This project helped to identify the factors that affected the efficacy of transgenic Bt cotton plants to control Helicoverpa punctigera and H. armigera. This knowledge contributes the design and refinement of the resistance management strategy for the commercial use of transgenic cotton plants

This project aimed to estimate the capacity of Helicoverpa armigera to develop resistance to INGARD cotton, to examine the possibility of cross-resistance to other Bacillus thuringiensis (Bt) toxins and to elucidate the mechanism(s) underlying that resistance. We have used several approaches to selecting H. annigera for resistance to CrylAc, the toxin expressed by INGARD cotton. This involved presenting the toxin in two different formulations and selecting insects for the next generation on two different criteria. By the end of the current project we were seeing the beginning of resistance in at least two distinct selection lines. The slow rate at which H. armigera developed resistance is encouraging for the industry but has delayed our investigation of cross-resistance and mechanisms. In parallel with the selection experiments we investigated the potential of various factors to increase the toxicity of Cry1Ac. We have tested the interactions between Cry1Ac and different Bt toxins, some proteinase inhibitors (to reduce the degradation of the toxin), and chitinase (to provide the toxin easier access to the midgut epithelium). There was no interaction between Cry1Ac and Cry1Ab or other Bt toxins that have very slight toxicity for H. armigera. Surprisingly, the two most potent toxins (Cry1Ac and Cry2Aa) proved to be antagonistic, although only slightly so and this antagonism is not expected to be evident in pyramided plants. Although the proteinase inhibitors and chitinase showed some effects on growth rate of H. annigera, the effects were not large enough to be useful.

Nine insecticide trials were carried out for control of silverleaf whitefly. The evaluation of control performance was greatly hampered by the considerable variation in whitefly numbers. The insecticides acetamiprid, imidacloprid, pymetrozineand trizapentadiene and the mineral oils, DC Tron and Synertrol gave evidence of good control. Bifenthrin showed variable efficacy. Some rotation strategies (pruticularly beta-cyfluthrin followed by imidacloprid and bifenthrin followed by imidacloprid and imidacloprid + Syne1trol followed by betacyfluthrin + Synertrol and bifenthrin + Synertrol followed by imidacloprid + Synertrol) were effective.

The review was initiated by the Australian Cotton Industry Council in response co grower concerns and m part dissatisfaction with aspects of rhe present classing system. 1.1.2 The project was managed by a project sub-committee which included representatives of growers, researchers, classers and shippers.

Objectives The dynamics of beneficial insect communities in cotton agroecosystems and the role of alternative crops in producing natural enemies for cotton * To quantify the seasonal phenology and abundance of key benefi.cials of cotton pests in other parts of the agroecosystem, including uncultivated habitats. * To evaluate the potential of a range of nursery crops for beneficials. some of which may also be effective trap crops for Helicoverpa, and explore methods of integrating them into cotton production systems

A variety of proteins were purified from cotton seeds and were analysed by amino acid sequence determination (automated Edman degradation) and by state-of-the-art electrospray ionization mass spectrometry (ESMS). The amino acid sequences of about 40 vicilin-related cotton proteins were precisely defined. The molecular masses of the deduced sequences were in agreement with the masses observed by ESMS to within about 1-2 Da (i.e. to within the mass of 1-2 hydrogen atoms). A further major cotton seed protein was purified and shown to be a y-conglutin-related protein with 2 component subunits and a molecular mass of 46250.3 1.3 Da. The vicilin fractions and the yconglutin variously have anti-fungal activity against a wide range of fungi tested including the cotton pathogens Fusarium oxysporum and Verticilium dahliae. This precise work is potentially useful for classical and transgenic approaches to cotton plant breeding for pest resistance. Cotton leaves also contain anti-fungal components and a defensive component with larvicidal activity against the blowfly Lucilia cuprina and the mosquito Aedes camptorhynchus. Large-scale purifcation procedures were developed to enable further biological testing. Protein and non-protein fractions from cotton are variously active as inhibitors of animal cyclic AMP-dependent protein kinase and of the proteases trypsin and chymotrypsin

The commonly used Micronaire value for cotton is related to both fibre fineness and maturity. There is a need for a new measurement technique to separate these. This is of particular importance to the Australian industry where varieties of fine mature cotton have the potential to be wrongfully discounted commercially by misinterpreting a low Micronaire value as indicating immaturity in a coarser fibre. Recently CSIRO Division of Wool Technology has developed a new instrument for measuring wool fibre diameter, the Sirolan-Laserscan. It is now in commercial use worldwide. Recent preliminary studies using wool have demonstrated that the Sirolan-Laserscan can be used in a new mode of operation to give independently both the average fineness of a sample as well as information on the fibre cross sectional shape i.e. fibre maturity. This preliminary project was designed to extend these studies to see if the Sirolan-Laserscan, in this new mode of operation, can be applied to cotton. Fourteen cotton samples whose fineness and maturity values had been measured in previous work sponsored by CRDC formed a useful set to evaluate the approach. These samples covered a broad range of both fineness and maturity values. A good correlation was found between the average fibre fineness measured by the Laserscan and the previously reported values. These encouraging preliminary results indicate that, in this novel mode of operation, the Sirolan-Laserscan can be used to determine the average fibre linear density or fineness of cotton samples. Following this successful preliminary study the next stage will be to examine possibilities of simultaneously measuring fibre maturity using the Sirolan Laserscan and the scope for scaling up the technique from the laboratory to become a useful commercial measurement technique