The SOILpak project so far has concentrated on the grey and brown cracking clay soils used for cotton production. The aim of the project has been to collate the vast amount of information available on these soil types into a usable form. Many papers have been written and submitted to reputable journals and a lot of information resides within people's minds. The SOILpak team's aim has been to extract and gather the relevant information and present it in a single package.

AIMS 1. To extend the understanding of compaction/degradation of Namoi grey clays (developed in previous project) to cover the range of soil types important for irrigated cotton. 2. To classify the various soil types according to their susceptibility to degradation under a given set of conditions. 3. Hence to provide consultants, extension workers with guidelines for assessing compaction susceptibility of their soil types.

This project has achieved its stated goals in that a gene which confers tolerance to 2,4-D has been isolated and engineered for expression in plants. Good tolerance levels were observed in a model plant species and efforts have now turned to cotton. The project will therefore be funded through our genetic engineering of cotton project for which a separate application will be made in the 1990/91 financial year .

The objective of this project was to acquire graphics hardware and software to allow computerised production of high quality graphs, diagrams and maps for reports, publications and conferences.

The first aim of this project was to define a protocol by which regeneration of cotton plants from tissue culture can be consistently and regularly achieved

The aim of the project is twofold: to draw up a nitrogen budget for cotton under various conditions that are known to affect the crop's response to nitrogen; and to continue to develop the SJRATAC fruit model, in particular by refining the cotton nitrogen sub-model. The value to the industry will be to improve the efficiently of nitrogen fertilisation and pest management. Cotton growers apply between 100 and 200 kg/ha of fertiliser nitrogen to the crop, costing the industry as a whole approximately $15 million annually. At best only 50% of the nitrogen applied is taken up by the crop. Study in more detail of the fate of all nitrogen applied to the crop, and the factors affecting it, is a vital step towards improving the efficiency of nitrogen fertilisation. Incorporation of nitrogen in the SIRATAC fruit model with strengthen the application of SJRA TAC pest management to situations where nitrogen is limiting, and will be a step towards using the SIRATAC model for nitrogen management

AIMS 1. To determine the mechanical and physical consequences of land preparation and harvesting on the soils and to relate these effects to soil water content. 2. To develop and assess methods for ameliorating undesirable physical conditions in heavy clay soils. 3. To develop and assess methods for predicting and classifying clay soils with relation to susceptibility to deformation, consolidation and shear under load during cultivation and harvest.

Summary of results: This project was needed to assess the N fertiliser requirements of cotton under new tillage systems currently being adopted, particularly since the structure of cracking clay soils is prone to degradation under intensive cultivation and traffic of continuous cropping. With little chance of extreme drying and cracking to restore soil structure, the trend towards continuous cropping may force soil management towards systems that allow maintenance and natural regeneration of soil structure. Such systems are likely to be based on permanent beds with minimum disturbance. Following is a summary of results; a detailed report is appended.

Ms. McRae presented a paper titled 'Characterisation of enzymes in the spore matrix of Colletotrichum orbiculare". Attending this conference allowed the applicant to discuss her work with leading _plant pathologists in that field.

ABSTRACT: When searchinq for an ideal mass screening technique for cotton plant antibiotic resistance to Helicoverpa spp., a 48 hour feeding on squares using final instar larvae bioassay was found to be the most suitable. It correlated better, than the techniques trialed, with the Standard larval bioassay traditionally used as an antibiotic resistance measurinq tool and was more energy efficient than the 'Standard'. An ideal mass screening technique usinq the two spotted mite (Tetranychus urticae} on cotton seedlings failed to correlate with the 'Standard1 rendering it unsuitable for measuring antibiotic resistance to Helicoverpa spp . ...The widely reported finding that gossypols are very important to the antibiotic activity against the cotton bollworm (Helicoverpa arnigera was supported with highly significant correlations between gossypol content of plant material and percent larval weight gains. In contrast, condensed tannin content of 'fresh plant' diet incurred insignificant antibiotic activity against the cotton bollworm but important antibiotic activity against the two spotted mite (Tetranychus urticae).