In 2000/01, the Australian cotton industry produced approximately 3.4 million bales with a gross estimated value of 1.7 billion dollars. Although cotton production in Australia is efficient, diseases, such as Fusarium wilt, are causing severe production losses. Unfortunately, the incidence of fusarium wilt in Australia has been increasing since it was identified in NSW daring the 93/94 season (Kochman, 1995). The disease is now present in many commercial cotton fields in NSW and Queensland. Although the resistance of elite Australian cotton cultivars is improving steadily, increasing the Fusarium wilt resistance of cotton cultivars remains a priority. While Australian cotton breeders are actively trying to enhance resistance to Fusarium wilt in their current breeding materials, they are also searching for novel sources of resistance genes. One possible source of new gales may be the native Australian Gossypium species, that are distant relatives of the cultivated cottons.

Australian cotton production areas are prone to significant damage by hail storms. Following a hail strike, a grower is left with trying to make the most out of what remains of his crop. There are few guidelines or criteria available to assist growers in making management decisions in regard to their hail damaged crop. A three year project looking at the management of hail damaged cotton crops, instigated and funded by the Cotton Research and Development Corporation, was begun in the 1993/94 season with the aim of developing some guidelines for managing hail damaged cotton crops

Black rootrot of cotton has been observed in 98 per cent of the farms regularly surveyed by NSW Agriculture in the Macquarie, Namoi, Gwydir and Macintyre valleys. The disease has potential to cause up to 40 per cent yield loss. The disease develops over time when the fungus T. basicola is present in adequate numbers within the vicinity of cotton roots when the environment is favourable for infection. The management strategy for this disease, therefore, could be based on four important components of the disease pyramid host, pathogen, environment and their interaction over the time.

A project examining ways of improving the water use efficiency of cotton through breeding has now been completed. This paper summarises the results of four years research. There was an interaction between cultivar and water environment, created by two okra leaf cultivars, Siokra L23 and Siokra 1-4 yielding relatively better under raingrown compared to irrigated. Cultivar maturity was highly correlated with raingrown yield and for each day increase in maturity yield increased by 34.4 kg/ha. Longer season cultivars had greater agronomic and leaf WUE than shorter season cultivars. This maturity, together with okra leaf produced the greatest WUE. Heritability of WUE traits in breeding populations was moderate to low and may still have some utility as selection criteria. A breeding strategy is presented which incorporates new techniques into the current breeding programme

Spray application technology

The intent of this guide is to give cotton growers information relating the impact of known concentrations of a herbicide on crop growth, exposed at a given crop growth stage, on crop growth and development and final yield. While every crop and every season is different, this information should provide some guidance as to the likely impact of herbicide exposure to a cotton crop.

The Herbicide Damage Guide is a work in progress and covers only a limited range of herbicides and exposure rates. This data base will be expanded over time.

Information can be sourced directly where the nature of the herbicide exposure is nown via the Herbicide Damage Information, or indirectly, using the Herbicide Damage Identification Guide to identify the likelyherbicide or herbicides that may have caused the damage.

There is an truism of journalism that the founding, and very successful, executive producer of 60 Minutes, Gerald Stone loved to repeat to his staff. It is one that will have special resonance for cotton growers. It is 'no-one is interested in flood control. Everyone is interested in Noah'. In other words, it is people and their experiences, which capture the media's interests, rather than the explication of issues. Tragedy will draw interest, but so too should good news stories, though they can often work well when you least expect it.

Soils of high acidity are a major limitation to crop productivity in much of the world. In Australia acid soils covers about 40% of the total land area. Although soil acidification is a natural process but modern agriculture practices have accelerated acidification of soils compared with natural ecosystems in southern Australia (Bromfield et al 1983; Lewis et al 1987). Approximately 30 million hectares of acid soils have developed after land clearing since European settlement. Among various soil acidifying processes, leaching of nitrate produced by legume nitrogen fixation and from the application of ammonical fertilizers, and removal of bases in crop harvests, are the most important factors in increasing soil acidification rates in Australia. Heavy clays, predominantly used for growing cotton in northern NSW, are generally alkaline and contain some free calcium carbonate in subsoil. Therefore, presently there appears to be no cause for concern from soil acidification in such soils. Other soils particularly, lighter textured Red Earths and Red Brown Earths characterised by neutral or slightly acidic pH, are also used for cotton production. These soils may have a potential acidification problem.

The textile industry is well aware of the different bleaching conditions for cotton and wool. For the bleaching of cotton/wool blends, techniques that are efficient for both fibre components and cause minimum fibre damage, are essential. In order to minimise the damage to the wool component, industrial jig bleaching procedures for cotton/wool blends are based predominantly on the conventional wool bleaching process with hydrogen peroxide under mildly alkaline conditions, followed by a reductive bleaching treatment. Under these bleaching conditions, the cotton component in the blend cannot be adequately bleached, leading to an overall unsatisfactory bleaching performance and product quality of the blend. In addition, due to the relatively tight structures of woven substrates, a longer treatment time and/or more severe conditions are often required for wovens to achieve an equivalent white to the corresponding knitted goods. Although slight modifications of the peroxide bleaching conditions have been attempted in industry to improve the bleaching effectiveness, they often compromise the product quality.

Fusarium wilt was identified on the Darling Downs in the early 1990's and the disease has now been found in most cotton growing areas. The extreme levels of plant death and yield decreases from the disease, coupled with the rapid spread, have seen Fusarium emerge as a major threat to the future of the cotton industry in Australia. Soon after the disease was recognised CSIRO began screening our locally bred lines and numerous introductions from all around the world. Unfortunately we found very little resistance to the disease. The best of our varieties was SiCot 189, but it could not cope with high levels of Fusarium. Some of our varieties such as Siokra 14 were extremely susceptible. There was some correspondence with Verticillium wilt resistance (SiCot 189 and SiCala V-2 have some resistance to both) but not in all cases (Siokra V-16 has some Verticillium resistance but is very susceptible to Fusarium). Amongst the introductions tested only MCU-5, a variety from India, showed significantly better survival. Using the results of the screening nurseries a large crossing and selection program was initiated to tackle Fusarium.