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.

The performance of CSIRO varieties and new lines are evaluated each year in a series of regional trials, known as the Australian Cotton Cultivar Trial (ACCD. CSIRO and the QDPI have been running these trials since the 1974175 season. Currently the ACCT comprises thirteen sites representing all the major cotton growing areas. This wide testing provides a good estimate of overall performance while also enabling assessment of whether particular genotypes perform relatively better at some environments than others.

Raingrown cotton requires a considerable financial outlay hence many farmers seek to reduce their exposure or to 'hedge their bets' by planting in skip row configurations. Skip row provides a reserve of soil moisture beside the planted rows and use of these 'side' reserves extends, by a number of days, the period that a crop can continue to photosynthesise at a certain level compared to a solid planted crop. If effective rain occurs during this extension of time, it can translate to a yield increase and possible quality improvement. A deep profile of stored moisture works in exactly the same fashion, but this deep reserve is smaller than the skip reserve - combine the two, however, and the odds for a successful crop in a dry season are markedly improved. Figure 1 shows that the extra stored moisture at planting bas a big influence on final yield, especially in a dry year. Figure 2 shows how a skip row configuration extends the time period that higher levels of soil moisture are available to the crop. The plant is able to draw moisture from a distance of at least 2 metres from the plant line, drying the soil to the same degree as immediately below the row.

CSD conducts large scale variety trials in all the cotton growing districts each season. It is well known that variety performance often differs markedly from season to season. It is therefore desirable when choosing which varieties to grow to study results for as many seasons as possible. This has been done for a number of districts using the average variety yields from all the CSD trials conducted in various districts as a percentage of the CSIRO variety, Siokra 1-4. This variety in recent years has been included as the standard for comparison in all the trials. The Pioneer - Deltapine variety Deltapine - Acala 90 (DP90), grown in Australia for a number of years has also been included in almost all the CSD trials and its performance relative to Siokra 1-4 is also included. In some cases where a new variety has only had limited testing but is closely related to its predecessor (e.g. Sicala V-1 and Sicala V-2; and Siokra L22 and Siokra L23) results are combined ro allow a longer tenn perspective of performance

Rainfed or dryland cotton grown in the 550 to 600 mm. per year rainfall regions of northern N.S.W. and southern Qld. is a profitable summer crop alternative. The rainfall distribution tends to be slightly summer dominant while suitable soil has plant available water capacity of 1 00 to 140 mm. of water. The variability of in crop rainfall especially during late December and January co-incides with the maximum water needs of the crop, thus good sub-soiJ moisture is essential to reduce the risk of crop failure. In addition, soil surface in the crop needs to be rough with open cracks, or have a stubble cover to capture high intensity rain especially on sloping areas.