In 1993 a series of experiments were established in the Namoi and Macquarie valleys to study the effects and benefits of rotation crops for subsequent cotton crops. The results presented here, are the effects of 4 different rotations on soil moisture, in the Macquarie valley, during the 1993 season.

The aim of this research is to define the best rotation/management combination whereby yields and quality of subsequent cotton crops can be maximized and sustained over the long-term.

Competition for scarce water resources in northern inland New South Wales has raised concerns among irrigations about the specification of water property rights and the efficiency of use of water resources within and between sectors of the water industry. Recent severe drought conditions, questions concerning the extent to which water allocations are required for environmental management purposes, and speculation about long term urban and industrial demands for water, have fuelled these concerns.

The first Australian cloud seeding experiment was conducted by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in February 1947. In a spectacular demonstration near Bathurst in New South Wales, a single cumulus cloud seeded with 225 kg of dry ice produced an average of 13 mm of rain over an area of about 130 Ian2 while neighbouring clouds produced none. The Hydro-Electric Commission of Tasmania (HECT) first became involved with cloud seeding in 1964, jointly sponsoring a 5-year experiment with CSIRO which resulted in a statistically significant rainfall increase of about 23%. Recent discoveries In the field of atmospheric physics have prompted a re-analysis of CSIRO's early cloud seeding experiments with startling results. Some of their efforts including the New England Experiment, appear to have been far more successful at putting extra rain on the ground than at first thought Three separate cloud seeding projects sponsored by HECT in Tasmania spanning 14 years, have contributed further to our understanding and have confirmed that cloud seeding can routinely enhance runoff into Tasmanian storages by 10 - 20%.

Transgenic cottons expressing the crystal protein toxin genes from the bacterium, Bacillus thuringiensis (Bt) have progressed to the field testing stage and may soon become part of the Australian cotton production scene. Bt cottons offer the potential for highly efficacious use of the Bt proteins and for significant reductions in the requirement for pesticides to control Lepidopterous pests like Helicoverpa. These reductions should reduce environmental concerns associated with cotton growing, and from the viewpoint of IPM will allow the implementation of other novel management strategies which are not compatible with pesticide use (eg. food sprays, pheromones, various parasites and predators). In future these other methods may help in management of pests other than Helicoverpa. Bt cottons are thus compatible with many other IPM tools and will provide a new platform on which IPM systems can be based

What are the steps involved in producing a weather forecast? (a) Collection of meteorological information (b) Processing of this information (c) Preparation of the forecast (d) Distribution of this forecast (All this must be done in a time frame that enables step (d) to be actioned before the forecast period begins.) Advances in each of these four steps have been considerable over the last decade, and are resulting in more accurate and readily available information to assist with decision making in rural affairs. We will now look briefly at some of the progress in each area.

In 1992 we started work on an alternative way of detecting pesticide residues, based on the application of medical immunodiagnostic tests. This type of technology was introduced to the cotton industry last year, through the Lepton (R) test for Heliothis speciation. Immunoassays use antibodies that have been prepared in rabbits, mice or sheep to a particular pesticide. The pesticide molecules are too small to raise an immune response by themselves, so much of the art in developing a pesticide immunoassay consists of coupling a chemical analogue of the pesticide to a carrier, usually a protein that is foreign to the animal being immunized. The analogue must retain all of the characteristic features of the pesticide, but have a new chemical group in its structure that can act as a handle for coupling to the protein. Once coupled to the protein, the pesticide-protein "conjugate" is usually able to evoke antibodies, but for a useful test to be possible, antibodies must be evoked that can bind to the free pesticide, as it would appear in water and other environmental samples.

The irrigated cotton industry in Australia has been developed around major river systems to allow water to be pumped to farm storages and then recirculated on farm using flood irrigation techniques. Recent work conducted by the Department of Water Resources NSW, showed that levels of some pesticides, particularly endosulfan, exceeded ANZECC guidelines for the protection of aquatic ecosystems in river systems in northern NSW. Because of the close proximity of natural water courses to cotton paddocks, a major national research programme was established in 1993, jointly funded by the Land & Water Resources Research and Development Corporation (L WRRDC), the Cotton Research & Development Corporation (CRDC) and the Murray Darling Basin Commission (MDBC). An important part of this program has been a project designed to estimate the contribution that the aerial application of pesticides (specifically endosulfan), makes to chemical loads in the riverine environment by primary droplet transmission (drift), subsequent volatilisation and transmission on dust particles.

In 1994, the Australian cotton farmer must use a wide range of costly chemicals to harvest a profitable crop. These chemicals vary significantly in their degree of hazard. Some chemicals (e.g. the organophosphates) directly threaten humans and other animals, because of their effect on nervous function. Others, such as the pyrethroids, are innocuous to humans, but toxic to fish. Still others, such as the esters of 2,4- dichlorophenoxyacetic acid (2,4-D) used on crops like wheat grown in rotation with cotton, are of concern because of their mobility in air and their possible effect on nontarget crops such as grapevines or cotton. But currently, most attention is focussed on those that have potential environmental effects, such as endosulfan

In this article I will chiefly focus on the this problem on soils with adequate levels of soil potassium. First by briefly describing the factors that may cause a crop to develop premature senescence under these conditions and second by summarising some preliminary research on methods of predicting and preventing this problem.