In 1990, a C.R. & D.C. co-operation with the funded research project was begun, Industry Hail Scheme Insurers, to investigate and evaluate the hail response of cotton varieties currently grown in the Australian cotton industry. While the research will increase our understanding of the cotton plant's response to hail damage and may also identify better management practices to maximise recovery potential, the information collected will also enable the current loss assessment procedures to be updated as necessary.

As the Cotton Breeder for Deltapine Australia this presentation will concentrate on the breeding program and aim to cover the following *The performance of Deltapine Varieties in 1991 /92 *The specific factors Deltapine is breeding for in Australia *The future

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 (ACCT). CSIRO and the QDPI have been running these trials since the 1974/75 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.

The CSIRO breeding programs aim to produce varieties for all the different growing situations in Australia. Situations where special varieties are very important are for cooler growing areas and for Verticillium wilt infected soils. This paper will discuss our short season varieties and Sicala V 1 which, although not early maturing, is adapted to the cooler and Verticillium prone areas. A discussion of our varieties developed for the mainstream production areas can be found in the paper by Norm Thomson

Last season there were four (Siokra 1-4, Siokra L22, Sicala 33 and CS 189) CSIRO mainstream varieties being grown commercially in most districts. In addition the new variety CS 50 was trialled in most areas as was Sicala 34, the higher strength replacement for Sicala 33. In some districts, our three special purpose varieties (Sicala Vl, CS 7S and Siokra S324) were a.lso grown. Peter Reid will discuss their performance in his article.

This article will refer to narrow row cotton only as that currently being grown in 75 cm rows (30"). The older system of high density stripper cotton will not be discussed.The great theoretical advantage of narrow rows is to reduce early season competition between plants, giving potential earliness and yield advantages. This is achieved by maintaining the same sowing rate while decreasing row space. All results of high density and narrow row experiments show clearly that plant competition at the squaring and flowering phases reduce fruit retention and boll size, particularly of early bolls. The theoretical yield and maturity advantages of narrow rows depend on good retention of lower fruit.

Nitrogen management plays a key role in cotton production. It is the nutrient required in greatest quantity by the crop and it is the nutrient most often deficient. Despite a large investment in fertilizer N in cotton cropping systems, the efficiency with which it is used by the crop can often be very low. This efficiency can vary greatly from season to season, between different forms of management and between cotton cropping systems. Much of this variation can be attributed to variations in the amount of N lost from the cotton cropping system.

This project was established to find a simple, repeatable and reliable technique or series of techniques for consultants, extension personnel and managers to use to assess soil structural conditions in the field. These techniques are also being related to the more precise teclmiques that are used by research persormel. All of these techniques, both advisory and research, are being related to cotton root growth and yield.

Cotton growers began to realise in the late 1970's that compaction of clay soils may have been a cause of declining yields. Research over the last 10 years has confirmed those suspicions. Compaction can be a widespread and severe limitation to yield; it can also be avoided or repaired . Research findings are of little use on their own. Users must be convinced of the magnitude of the problem and be given ready access to information which can help them overcome a problem. The SOILpak project set out to address these issues by promoting the importance of good soil management, by drawing together existing research results and practical experience, and by presenting the knowledge in a decision-support system. A loose-leaf manual was the medium chosen to deliver the decision support system. This medium makes the information easily accessible, especially in the field where many management decisions are made.

The companion project to SOILpak, "Soil management training for advisers to cotton growers" has made a good start in familiarising consultants and agronomists with structural recognition. The series of soils workshops for consultants and agronomists that started in 1990 in the Macquarie Valley (Abbot 1990) is now complete following the running of the Central Queensland workshop at Emerald in May 1992.