This project had two major aims consistent with the overall goal of controlling Verticillium wilt in cultivated cotton (Gossypium hirsutum). The first aim was to employ molecular genetic techniques to differentiate between isolates of the fungal pathogen Verticillium dahliae in order to develop a better understanding of the epidemiology of Verticillium wilt disease in cotton. The second aim was to produce molecular genetic fingerprints of the wilt-tolerant cotton cultivars currently being developed by the CSIRO to assist in the identification and tracking of potential genes for disease resistance in the plant breeding program.

aims of this study were to: obtain base-line data against 12 pesticides and to conduct an initial evaluation of the current resistance status of field-collected cotton aphid strains. To that end laboratory studies were required to establish base-line data for Australian cotton aphid. Susceptible strains of cotton aphid were established and breed in purpose built cages. When sufficient numbers of aphids were available they were assayed against a range of established and potential pesticides to establish base line-data. Once generated, the base-line data was used to screen a number of field-collected strains for resistance.

To develop resistance management strategies for organophosphates (OP's) carbamates, insect growth regulators (IGR's) and new insecticide groups, such as the pyrroles based on a sound understanding of resistance mechanisms 2. To evaluate the importance of a newly discovered pyrethroid resistance mechanism and develop low cost, rapid biochemical techniques for the detection of pyrethroid, carbamate and organophosphate resistance.

Pyrethroid resistance levels in Helicoverpa armigera have continued to escalate slowly to around 80-90% but endosulfan resistance has stabilised at about half that level. Resistance to the partial resistance breaking pyrethroid bifenthrin has increased slightly but on average, resistance levels to this product are about half those to the other conventional synthetic pyrethroids. Profenofos resistance is still low in all areas except for an incipient problem in central Queensland. Via tolerance curve analyses indicate the emergence of elevated levels of pyrethroid resistance mechanisms. These ire synergisable by alternative mfo (mixed function oxidase) inhibitors to Pbo (piperonyl butoxide) and are overcome by synergophore pyrethroid analogues such as Series Two and prallethrin but not by esterase inhibitors nor by a non-ester pyrethroid analogue (silafluofen). This indicates the possible development of new isomorphs of P450 monooxygenases (mfos) synergised by alternate chemical classes of mfo inhibitors such as the propynyl ethers but not fully synergisable by Pbo. Laboratory studies indicated some potential synergists for field evaluation (ethion, malathion, phosmet) but most compounds tested were ineffective, including profenofos, trichlorfon, phoxim, azamethiphos and other esterase and glutathione inhibitors. Cyclodiene resistance did not give cross resistance to the avennectins. Baseline susceptible data and discriminating doses were evaluated for three classes of new insecticides; spinosad, the pyrrole chlorfenapyr and the avermectins (abamectin and emamectin benzoate). Abamectin was identified as a potential new replacement for endosulfan for early season Helicoverpa punctigera control. Helicoverpa punctigera resistance levels to both endosulfan and pyrethroids have remained low. )

A Heliothis NPV formulation, GemStar, showed promise as a basis for successful selective, non-chemical insect control on cotton. Trials were conducted with the virus as a stand-alone insecticide on dryland cotton at Dalby, Q. by D. Murray (QDPI), and in conjunction with Envirofeast on irrigated cotton at Moree by R. Mensah, (NSW Agriculture). On dryland cotton at Dalby, Qld, yields were equivalent to those with conventional chemical control at one of the two sites. The virus failed to contain a heavy infestation of Heliothis in February 1996, but neither did conventional insecticides. In an IPM programme on cotton with lucerne strip cropping at Moree involving 4 Envirofeast sprays followed by 3 sprays of the virus combined with Envirofeast and a clean-up chemical spray, yields were similar to those obtained with a conventional insecticidal regimen. Predator numbers were higher in the Envirofeast/GemStar plots than in other "soft11 treatments", Envirofeast/endosulfan or Envirofeast/Bt endosulfan, suggesting that any disruption to predators by GemStar was at a low level. Bioassays indicated that GemStar maintained its potency during on-farm, refrigerated storage. Levels of infection achieved on cotton were variable but the overall average was about 55%. This suggests that the use of the virus should be integrated with other Heliothis control measures. Thresholds frequently exceeded 2 larvae per row metre without undue damage to the crops, suggesting that this biocontrol system provided greater flexibility in control response than with chemical insecticides. This aspect requires further investigation to determine appropriate thresholds.

The project was teminated by CRDC after two years and therefore could not meet its final objectives. Good technical progress was made and the resources and information that were obtained remain available for the future. One particular benefit of the project was seen by the CRDC review. held in January 1995. as being that the knowledgeledge gained would assist in resistance management for Bt. In an unexected way it did this by highlighting the need for us to create a genetic ma Heliothis armigea. In the case of CSE36C. The re-existence of a genetic ma of the related American species. Heliothis virescens. Allowed us rapidly and cost-effectively to decide whether endosulfan resistance was due to a mutation in the GAB~ gene. Our abilty to use information from the American species relied on the ha1) y and unusual coincidence that endosulfan resistance is sex-linked (i.e. its chromosomal location ii/. Armigera is known). This is a rare. If not unique. Situation and almost certainly we will not have this advantage when we are faced with H. armigera resistant to Bt cotton. Creating a genetic map iii/.armigera before Bt resistance appears in the field would eliminate reliance on luck and greatly facilitate characterisation and detection of resistance genes when they a ear. It would do this by providing markers which could be used to determine the chromosomal location of any resistance genes. Even at the crudest level this would be a ve1y valuable tool. It is therefore one of the most cost-effective steps that the cotton industiy can take as insurance against Bt resistance.

The cotton plant has two main sets of traits that contribute to its resistance to pests: (1) chemical (e.g. gossypol) and morphological defences (e.g. okra-leaf) and (2) compensatory mechanisms for regrowth (e.g. bud dormancy). Defences are aimed at damage avoidance, while compensation refers to the ability of the plant to recover after damage. This project investigated compensatory growth in cotton on the grounds that a better understanding of the underling mechanisms could assist in better pest management practices. In two years of experiments we have advanced considerably in our understanding of cotton responses to three main types of damage: i) fruit damage, as caused by Helicoverpa and mirids; (ii) leaf damage, as caused by mites; and (iii) tip damage, as caused by earlyseason pests. Important physiological and morphological responses of the cotton plant have been identified that will be used to improve the capacity of the CERCOT cotton model to predict crop responses to pest damage. We envisage that such an enhanced version of CERCOT will be the core of the next generation of packages for pest management in the Australian cotton industry.

Capacity Sharing is an institutional arrangement and property rights structure for allocating water among multiple users of water resource systems which include storage reservoirs. It provides each user, or group of users, of reservoir water with perpetual or long-term rights to a percentage of reservoir inflows and a percentage of total reservoir capacity or space in which to store those inflows, and from which to control releases.

The aim of this book is to help cotton growers, field consultants and agronomists correctly identify the wide range of pests and beneficials that can be found in the crops they manage. Accurate identification is one of the foundations for making sound pest management decisions. When pests are correctly identified, the relevant thresholds can be applied and appropriate control measures selected. For beneficials, correct identification means that their potentially important role in regulating pest populations can be utilised more effectively

Instrument fibre tests indicate that there is no difference between the fibre from transgenic Bt cotton and non transgenic. However there is assumed concern from the spinning and textile sector. To overcome any doubts, and to improve confidence in the Australian transgenic varieties, a full commercial evaluation needs to be undertaken. Similar work with non transgenics has been supervised by the 1Fibre Research Management Group' (TexSkill, Rocklea, Bonds, University NSW, CRDC - plus occasionally CSD, CSIRO and Dr Stuart Gordon). In the past this group has organised parallel assessment by Schlatborst (Germany) and further testing by Zellweger (Switzerland) to add international confirmation.