Each furrow irrigation waterlogs most of the root zone of cotton in cracking clay soils. This deprives the roots of oxygen, they take up less water and nutrients. and this reduces growth and yield. Recent research at Narrabri has measured how much yield is lost through waterlogging, how much can be recovered by the tactical use of foliar applied N fertilizer, and to what extent irrigation management can reduce waterlogging.

Managing riparian vegetation for multiple benefits

A research project at the Australian Cotton Research Institute, Narrabri aims at developing biocontrol agents for cotton seedling diseases and Verticillium wilt. This paper describes some of the aspects concerned with the project.

Commercial cotton crops throughout NSW have been surveyed in November and March of each season since 1983 to determine disease distribution, incidence and severity. Cropping history, field preparation, seed rate, plant stand and the amount of crop residue remaining from the previous cotton crop have been recorded for each field inspected. Between 80 and I 00 commercial fields have been inspected in each survey.

Auscott's Midkin property at Moree has a long history of environmental and riparian management. It's been 14 years since work on the regeneration of riparian areas was initiated at Midkin back in 2001.

After 2 light mite years (1991/92 and 1992193) the cotton industry experienced a season in which outbreaks of mites were widespread. In most regions mites were reported from seedling cotton and mite populations began to increase in mid-December to early-January, about a month earlier than usual. A number of factors contributed to produce the potential for such outbreaks to occur and other factors made management of outbreaks very difficult. The key factors involved, as I see them, are detailed below.

The value of lucerne as a trap crop for cotton pests has been recognised in America for some time (Deloach and Peters 1972, Robinson et al. 1972, Sevacherian and Stern 1974). The major use of this cultural control technique in America has been for trapping the Lygus bug. Although possibilities of strip cropping for insect control have drawn considerable interest from Australian farmers, few studies have been done on the effects of strip cropping on the pest/predator complex of Australian cotton. Mirids, the Lygus bug's Australian relative, are an occasional pest of cotton in the Macquarie valley of NSW. An experiment was devised to determine the effect of strip cropped luceme on the spatial and temporal distribution of pests, including mirids and Helicoverpa, and predators within a commercial cotton crop.

From a humanised viewpoint cotton may be thought of as a lazy plant. It "employs" microscopic fungi to do some of the hard work of collecting nutrients from the soil. This type of relationship, a symbiosis, is known as a mycorrhiza (literally: "fungus root"). Usually both partners in a mycorrhiza benefit from the relationship.

The overall aim of the project is to examine the response of cotton to Pix (mepiquat chloride) under different growth rates in the Macquarie Valley. The plan is to target a variety of cotton crops over two to three seasons that have dissimilar growth rates and fruit retention. The work will evaluate whether research completed at Myall Vale Research Station (near Narrabri), is pertinent to the shorter season growing conditions of the Macquarie Valley or otherwise.

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.