Aims: 1. To determine the rates, form and placement of fertiliser appropriate to alleviate potassium deficiency and premature senescence. 2. To further research the role of potassium in the resistance of cotton to Altemaria leaf spot.

Report on Overseas Travel, June-July 1994 Helen McFadden

The funds requested in the application were for Dr Christian to spend 6 weeks in the laboratory of Dr Art Mcintosh and Dr Carlo lgnoffo in Columbia Missouri, working on aspects of the project "Genetic Engineering of Heliothis Nuclear Polyhedrosis Viruses: Pre-commercial Development" Dr Christian and Ors Mcintosh and lgnoffo have an on-going collaboration looking at various aspects of the biology and ecology of Helicoverpa nuclear polyhedrosis viruses (HaNPV). As part of this collaboration Dr Christian had previously spent three months in Columbia in 1992 studying aspects of the in vitro production of HaNPVs and their in vivo activity against a variety North American noctuid species. The collaboration continued further when Dr Mcintosh undertaking a six month McMaster's Fellowship in 1992/93 in the Division of Entomology to develop new cell lines from Australian Helicoverpa species

In order to obtain information of its environmental fate under conditions of use in the Australian cotton industry, this major study was initiated in 1990-91. It represented the first case of a systematic analysis of the fate of endosulfan under Australian conditions. The experimental strategy used was to conduct random sampling of soil throughout the year on several fields used for cotton growing. From analysis of these soil samples for endosulfan residues, it would be possible to discover the rate of breakdown and to estimate half-lives (the time to reduce the concentration in soil to half its current value) and to identify the chemical products. This would allow an assessment of whether endosulfan was likely to cause long-term problems related to its accumulation in soil and its potential threat to the environment.,

During this trip I was able to liaise successfully with the following colleagues concerned with resistance and its management: Drs Rick Roush (Cornell), Alan Devonshire (Rothamsted), Chris Curtis (London School of Hygiene and Tropical Medicine) and Alan McCaffery (Reading University). Outcomes of the discussions were: (1) I received affinnation that the likely nature of the pyrethroid resistance recently detected in St George, was an esterase-mediated mechanism, as suggested by Dr Robin Gunning. I established contacts relevant to the new project on the esterase resistance in Helicoverpa armigera. Clones for the para gene for kdr resistance and for esterases were made available. (2) I was given up-to-date information on pyrethroid resistance studies in H.. armigera in India and Thailand, and Heliothis virescens in the USA. It appears that kdr type resistance is not common in Asian populations of resistant H. armigera as was first thought. In particular, the dominant form of pyrethroid resistance in India is metabolism Endosulfan resistance has been detected in Pakistan H. armigera. (3) I discussed different aspects of resistance management to transgenic plants. As a result, I have become concerned about the directions being taken in models overseas that seem biased towards seed mixtures as the preferred control strategy. This bias arises more from social/political constraints in the USA cotton industry than because it necessarily is the only viable option to manage Bt plants. However, seed mixtures do seem to be the 'best' biological option in potato crops for the control of Colorado potato beetle because this insect is not very mobile

The first process in facing up to a season without water is to set some rules and make certain assumptions. Assumptions can be based on previous experience, fact or fiction and can incorporate any degree of risk. In essence, its a question of looking at the known e.g. available land, water currently available from the dam and on farm storage, then taking a position in respect of future outcomes. For example, expected average rainfall, (more or less) and the likelihood of future irrigation water from storage and surplus flows. Then, you need to provide enough flexibility in the system to take advantage of changed circumstances and opportunities.

Cotton is but one of a number of fibers which the consumer can use to satisfy the need for clothing, household articles and industrial products. Among natural products, in addition to cotton, there are animal furs, animal hairs such as wool and mohair, silk, flax, jute, coir, sisal, henequen, abaca, ramie and minerals such as asbestos. Among synthetic products there are nylon, polyester, acrylics, polypropylene and glass fibers. Rayon and its filament form -- acetate -- are technically artificial fibers, made from natural cellulose usually in wood but dissolved and recombined in a fiber form

Pengelly Farming Pty. Ltd. is a family owned and operated business in the Bowenville area of the inner Downs. our business is a mixed enterprise of grain, cotton and cattle fattening carried out on an aggregation of 6,500 acres which is land owned, sharefarmed and leased. Soil types vary from brigalow scrub and box to heavy black flood country. We have been growing dryland cotton for five years.

Simulations were run to test the sensitivity of OZCOT to varietal differences in developmental characteristics known to influence fruiting dynamics in cotton. Thirty one years of historical weather data from Myall Vale were used. The results indicate that the model is responsive to varietal differences over the actual range measured in two field experiments; both in terms of yield and time to 60% bolls open. Simulated changes in time to 60% bolls open were consistent with experimental evidence. It is therefore necessary to allow for these differences as inputs to the model and to measure the developmental characteristics for new cultivars to keep the model relevant to current production practices.

Australian Rainfed Cotton has been grown with startling results over the last 10 - 15 years. We have had some growers in the more favoured areas averaging over 2 bales/ acre while growers in more marginal areas have left the industry due to unprofitability. As the bulk of our crop has always been irrigated, the largest part of the research dollar has been spent on irrigated cotton. Rainfed cottongrowers have largely taken this data and used it directly on their farms. In more marginal situations this would appear to have some drawbacks.