Disease Surveys. Commercial cotton (Gossypium hirsutum L.) fields in the Mcintyre, Gwydir, Namol and Macquarie valleys of New South Wales were inspected in November and March each season. Commercial fields in the Bourke area were also inspected during March surveys. The incidence and severity of bacterial blight on Deltapine cultivars has been significantly reduced in recent years. The disease was not observed during the November 1991 survey. Verticillium wilt was present in a significant proportion of the fields inspected in all areas. The disease was most prevalent in crops in the Namoi valley where it was present in over 90% of crops and where the mean incidence for the last three seasons has been over 25%. The increasing incidence of verticillium wilt in individual fields that have been surveyed on several occasions during the last six seasons is of particular con cern. Seed/seedling losses have varied from 27.5% in the 1991/92 season to 41. 2% in 1989 /90 with the greatest losses occurring in the Macquarie Valley. The incidence of Phytophthora boll rot has generally been low although wet conditions in February 1990 resulted in a mean incidence of 2 .67% with up to 26% of bolls affected in one crop. Alternaria leaf spot was rarely observed in New South Wales with the exception of some isolated areas. The disease was regularly observed causing some defoliation late in the season in crops on the property 'Red Mill' north-east of Moree. Low infestations of Alternaria leaf spot are often seen in the Maules Creek area east of Narrabri and the disease was also observed on crops of 'Pima' in the Bourke area in February 1992. Over recent years and in most gin yards there h as been an increasing occurrence of module rot associated with the entry of water into the module - especially around tarp ropes. The seed cotton becomes discoloured and a species of Coprinus (the 'inky cap' mushrooms} is often present.

SUMMARY We have generated an antibody which is absolutely specific for H. armigera over H. punctigera. Specificity has been demonstrated in a number of ways. For example, the antigenic protein from H. armigera and its homologue from H. punctigera were purified and probed with the kit MAb. No detectable reaction was observed against H. puncti.gera under conditions where a very strong reaction was observed versus the H. armigera protein. The experiments indicate that a very high level of species-specificity is an inherent property of the kit antibody. We have incorporated the anti.body into a prototype ID kit which has now been tested under field conditions. The kit is not yet of commercial quality and reliability. Nevertheless, for eggs collected from the field at a single time and place, there is a high correlation between the % H. armigera detennined by the kit and as determined by rearing (Trowell et al. 1992). This indicates that the basic design of the kit is sound and further development is worthwhile. We are working on reliability problems which have been thrown up in the field tests and have made significant progress in overcoming them. The problems are of the kind normally encountered in development of this type of test kit Together with a partner experienced in immunodiagnostic production, we expect to be able to produce a kit of commercial quality

To develop, validate and implement a regional model of Helicoverpa population dynamics which considers the abundance, movement, oviposition, development and mortality of H.armigera and H.punctigera on all major hosts within a given region. The purpose is to provide an interactive simulation model which can predict the regional dynamics of Helicoverpa populations in response to climatic, biotic, and agronomic conditions.

During August 1990, in company with Dr Norm Thomson, Mr Reid visited a number of research institution and companies form California to Mississippi. The main purpose of the trip were to survey trends in US cotton breeding, to get to know American breeders personally, and to become more familiar with the US cotton belt.

I was invited to speak at the conference to give a paper at one of the sessions. My paper was entitled "Mechanical Problems in Soil/fool Interaction", and covered the soil mechanics of tillage and compaction by vehicle tyres and tracks. The talk was based on my work in the cotton industry over the last few years.

A 20 saw gin was bought for $13,000 from the USA. It was installed and fitted with a motor in time to be used in the 1991 harvest It operated satisfactorily throughout the 1991 season.

This project was concerned with the transfer of cotton fibre testing from the Division of Wool Research, Geelong Victoria to the Cotton Research Unit at Narrabri Agricultural Research Station (NARS). It involved the construction of a fibre testing laboratory within the CSIRO field shed, the purchase and installation of a Spinlab 900 series HVI length, strength and micronaire instrument by January 1989 and the purchase and installation of a Shirley Fineness Maturity Tester (FMT III) the following year. The project also called for the employment of casual staff to operate the equipment under the supervision of CRU staff and provided for the maintenance of the equipment.