We have conducted in field experiments for the past two years to develop a food product that can be used to attract, conserve and augment natural enemies especially predatory insects in cotton fields and utilized them as basic components of IPM programme to manage Helicove1pa spp and other pests on cotton. The results of these experiments are reported here.

The HEAPS (HE.licoverpa d.rmigera and l!.imctigera Simulation) model embodies all of our current knowledge on the ecology of Helicoverpa within cotton cropping regions. It differs from other models of Helicoverpa population dynamics in two main ways. Firstly it operates over an explicitly defined spatial representation of the agricultural landscape within the region being simulated, and secondly it simulates multiple sub-populations of Helicoverpa, each of which have their own demography and resistance gene frequencies. By necessity the model is a simplification of the real world, and there are many underlying assumptions governing its predictions. The HEAPS model is still in the process of being validated on a regional scale, and therefore the accuracy and precision of its predictions remain to be proven. However the model has already been a useful research tool for studying a range of issues relating to the regional population ecology of Helicoverpa. It is in this regard that we outline the use of the model to simulate the demographic and genetic response of H. armigera populations to IRM strategies (see Tabashnik, 1990)

Questions are often raised about whether trace elements are required on cotton. Zinc deficiency has been confirmed in areas where topsoil has been removed, and zinc application is common in many areas, despite a lack of evidence for a general zinc response. More recently, copper has been proposed as deficient in some areas. With this background it was decided to sample soil and plants from a number of cotton fields from Warren to Boggabilla. The soil was sampled to 30 cm depth as near to planting time as possible. Leaf and whole plant samples were taken from the same fields during flowering. These samples were analysed for zinc, copper, iron and manganese. In addition plant samples were taken at regular intervals from experiments at Narrabri to determine the pattern and extent of uptake of each trace element.

Growers with cotton in their rotations achieve higher returns over the rotation cycle, compared with growers with solely grainbased rotations. And improvements in variety characteristics, performance and technology traits over recent years have simplified the process of growing raingrown cotton making it a safer, more reliable and consistent performer

the industry's researchers and scientists got together in Toowoomba for the Australian Cotton Research Conference (proudly supported by CottonInfo partners CRDC and CSD). Over 130+ research presentations covered the fields of plant, soil and systems; cotton breeding; weeds; entomology; energy; carbon and climate; nutrition; NRM; pathology; irrigation; fibre and processing; and social science. In today's enews, we're bringing you some of the (many) highlights. You can read the abstracts from all 130+ presenters in the Conference booklet.

Water availability will be a key consideration for some (if not all!) growers during the coming season. So in this edition, we take a look at management options for growers with a limited water supply.

In this edition of the CottonInfo enews, we bring you two of the key things you need to know from the Guide: the herbicide and insecticide resistance management strategies.

Establishing the cotton crop is a critical operation, setting the standard for the entire season. Here's what you need to know, courtesy of CottonInfo partner CSD and the Australian Cotton Production Manual.

Drip irrigation has been of interest in regions where water is scarce or expensive (e.g. Israel and Arizona). In Australia the water supply is very variable, while the cost of water, though cheap by some standards, could become more expensive in the future. Claims by distributors and agents of improved efficiency of irrigation and heavier yields of cotton due to drip irrigation in 1981-82 and 1983-84 had not been validated for Australian conditions. This created the need for an objective assessment of drip irrigation for cotton. This project compares two types of drip irrigation and standard furrow irrigation in a randomized and replicated experiment.

Several factors influence the nitrogen demands of a cotton crop and the ability of the soil and fertiliser to satisfy these demands. Some of these factors (eg weather) are beyond the control of a cotton grower. One of the skills of cotton growing is having agronomy , especially fertiliser application strategies, that are least penalised by adverse conditions. Additionally, and especially during times of low prices, no grower can afford to miss any yield. This article outlines key principles arising from nutrition experiments and describes the options when deciding on fertiliser rates.