AZADIRACHTIN is a terpinoid chemical !ound in Meliaceous trees (e.q. White Cedar) but especially concentrated in the seeds of the Neem tree (Azadirachta indica). After considerable research in India, En<~land, the U.S.A., Japan, Germany and Australia; plus three international conferences, it is generally considered that this molecule is our best hope !or a safe and selective insecticide !or the 1990 s and beyond. It acts specifically on the sensory receptors of insects and their allies and also on their neuro-hormonal system, effectively disrupting their behaviour, growth, moulting and reproduction. The several modes of action of azadirachtin make it much more difficult for insects to become resistant to it. Not one case of an azadirachtin resistant insect species is known.

The Australian Bureau of Agricultural and Resource Economics is one of the few organisations that publish cotton pri ce forecasts t o assist growers in making their planting decisions. The US Department of Agriculture, for example, is forbidden by legislation from publishing cotton price forecasts for fear of influencing actual market outcomes. Consequently, the Bureau has a responsibility to ensure t h at its forecasts are as sound and as accurate as possible, given the data available to it at the time. Thus , the objective of recent research has been to improve the subjective forecasting process that was previously used by the Bureau through the development of an economic model of the world cotton market. Using this model, structural characteristics of the market have been studied and the effects of US farm policy have been analysed .

Australian Cotton Conference. I have been asked to speak to you on the effects on the industry of the US Farm Bill and other political moves. To be frank, I have to admit that as a non-researcher in a technical sense, I am much happier talking on this subject than on blight, spray technology, genetic engineering and the like. I would commend the Association for including in its Conference a sector on marketing and the industry. The simple fact is, without an open market and the capacity to trade internationally, your research activities become rather academic.

I will admit, nonetheless, that there are opportunities to be grasped on occasions such as this, since one can use them (whether they be publicly documented or not) to say things that wquld be inappropriate in one's normal work. And what I invariably find myself saying is this: be sceptical; the geographical and ideological divisions in the raw cotton market distort your picture much more than you imagine.

Ripping (deep soil working ) can give conflicting responses. Sometimes it i ncreases cotton yields and other times it de creases cotton yields. The aim of this paper is to summarize t he position on ripping and to draw basic principles from the information we have. Some basic principles are discussed below as 'rules for ripping'.

In addressing this topic I have been asked to consider the development of management strategies for farmers faced with a shortage of irrigation water, a situation that appears endemic in the Gwydir Valley. Ten years ago Greg Constable and I showed in an analysis of our experimental data that 8 Ml per planted ha are needed for maximum yields in the driest years, while 7 Ml/ha gives the greatest remrns per Ml on average by allowing a larger area to be planted with a given allocation. When the allocation is reduced, greatest returns would be obtain on average when the crop area was reduced to allow 6 to 7 Ml for each planted ha. With less than 6 Ml per ha the risks of obtaining yields below the breakeven point were very great and there was no advantage in delaying the first irrigation or increasing the interval between irrigation

Having outlined the complexity of this topic, I now intend to summarise the soil and plant mineral relations during waterlogging, followed by a brief review of the scientific principles to improve understanding of the problem and to point to methods of dealing with it. Key references are listed to enable those who wish to delve further into the scientific literature.

Proper nutrition is one of the many factors necessary in achieving the high yield and quality standards we have set for our cotton crop. Laboratory testing can reveal situations where more or new nutrients should be added to a crop. Unfortunately there have been bad experiences with predicting fertiliser use based on laboratory tests, but these experiences, plus research and new equipment should be used to our advantage. Most cotton growing soils are relatively fertile. However there are three categories of deficiency where fertiliser use is necessary for maximum production:

Nematodes are regarded as a major pest of cotton in many parts of the world. It has been claimed that "nematodes cause economic losses to cotton everywhere it is grown" (Watkins. 1981). Apart from yield reductions resulting from nematode activity alone, nematodes are often involved in interactions with other plant pathogens. The interaction between fusarium wilt and the root knot nematode is well documented. Nematodes usually are favoured by well drained light-textured soils. In recent years plant parasitic nematodes have been found in wheat growing on the heavy textured soils of north-west NSW.