During the 2008/09 season, a number of cotton fields in Theodore had problems with seedling establishment in areas where large numbers of symphyla were present. Plants also showed signs of water stress and the roots displayed a distinctive branching pattern known as a 'witch's broom'

Soil compaction is a well known risk with most cotton soils and can have significant consequences for productivity. The cotton industry is well aware of compaction risk and operations/rotations to manage ongoing problems. Cotton picking has changed dramatically with the rapid adoption of round bale pickers. The substantial increase in weight raises the question -what is the implication for compaction ?

This project commenced in 2002 to monitor DD across a range of irrigated cropping lands in the upper Murray Darling basin. At its peak, there were 11 sites where lysimeters were installed (all but one in commercial, irrigated cotton fields) giving a total of 33 lysimeters with one near the head ditch, mid field and tail ditch in each field. This monitoring has continued but the project has widened to consider the related aspects of change in root zone salinity, whether DD (or other surface water events) are linked to groundwater rise, and most recently rootzone salinity change with new irrigation technologies aimed at improved WUE. This paper will present results from the five main subject areas of the project: (i) deep drainage, (ii) WUE and soil salinity implications with a lateral move, (iii) DD leachate water quality, (iv) resistivity imaging showing deep "pools" of water and salt below irrigated fields and (v) links of surface irrigation with groundwater response.

Soil organic carbon (SOC) increased throughout a 10-year monitoring period (1998-2008) in an experiment that compared five cotton-based cropping systems. These systems included faba bean, vetch and wheat crops, as well as fallows of up to 10 months. All crops were grown on permanent ridges using minimum tillage. Topsoil (0-30 cm) contained between 40 and 42 t SOC /ha in 1998 and increased by 0.28 t C/ha/yr (or 0.51 to 1.69 t CO2e/ha/yr) across the five cropping systems. Between 2006 and 2008, SOC was measured to 90 cm depth; this indicated that on average 2.2 t C/ha/yr was sequestered (equivalent to 8.1 t CO2e/ha/yr). The greatest accretions of C occurred in the subsoil: 13%, 38% and 49% of the sequestered-C was found in the 0-30, 30-60 and 60-90 cm depth intervals, respectively. SOC was 7% higher in the cropping systems that received legume stubble. Faba bean and vetch stubbles averaged 2.89 and 3.89% N, whereas wheat and cotton stubbles averaged 0.78 and 1.56% N, respectively. Carbon (C) inputs from crop stubble (excluding roots) ranged from 11.8 to 29.6 t C/ha over the 10-year period. Sequestered C vastly exceeded the estimated CO2e emissions typical of irrigated cotton cropping systems.

Whilst managing for fibre quality is in the title of this presentation, most of the focus is on yield. However, if you're producing high yields, generally you're also producing good quality; particularly the parameters of fibre length and staple strength.

Bioassays developed and extensive screening undertaken between 2007-10 * No changes in resistance factors in cotton from 2007 to 2010 * Elevated resistance factors recorded in horticultural regions for pyriproxyfen (Admiral) emphasise the importance of the cotton IRMS and a maximum one application Admiral per season * No changes recommended to current insecticide resistance management practices in cotton * Registration of spirotetramat (Movento) in the 2010-11 season with a unique mode of action will assist the insecticide resistance management strategy in cotton * Future directions in resistance monitoring need to address correlating resistance factors with field performance

The survey data showed a wide range of irrigation performance and water volume estimation and measurement across the industry. It found the average GPWUIfarm for the cotton industry was 1.14 bales per megalitre. This figure is a representative benchmark for the cotton industry for 2008/2009 and confirmed the previously revealed 40 per cent improvement by NSW DPI, since the last industry estimate 10 years ago.

The widespread adoption of glyphosate tolerant cotton in the last 10 years has substantially modified the weed control practices used in irrigated and dryland cotton crops. Data on changes in the weed populations, infestation levels and flora, and control tactics were compiled from field and industry surveys to compare changes in the weeds and practices used since the introduction of herbicide tolerant cotton. The focus was on three regions: Darling Downs with 36% dryland cotton grown, Gwydir (12%) and Lower Namoi (9%). Across the crop rotations, flaxleaf fleabane had increased dramatically in both dryland and irrigated systems, and there were more residual weeds in dryland than irrigated systems, particularly for bladder ketmia, flaxleaf fleabane, sowthistle and barnyard grass. The main weeds surviving within glyphosate tolerant crops, prior to implementation of remedial actions, were cow vine, flaxleaf fleabane, nut grass, bladder ketmia and barnyard grass, although relative importance differed between the regions. The approach to weed control over the last decade moved from pre-emptive use of residual pre-emergent herbicides to tactics for control of weed seedlings and survivors of glyphosate applications. Weed management practices were similar across the regions but differed somewhat between dryland and irrigated crops. The weed flora shift, threat of glyphosate resistant weeds, and the extent of weeds surviving in the other components of the rotation indicate the need for a more strategic approach to weed management to be applied across the whole cropping system.

Commencing in October 2009, the 12 month pilot program will measure the industry's responsiveness to government funded irrigation modernisation programs aimed at water recovery. Importantly STBBRG will also assist in guiding the development and implementation of future programs in other NSW Murray-Darling catchments

Aphis gossypii Glover (cotton or melon aphid) is an important pest of cotton due to its ability to reduce yield through feeding damage. Until the introduction of Bt-cotton to Australia in the mid 1990s cotton aphids were considered late season secondary pest because they were suppressed by insecticides used against other pests. However, from 1998-1999 season aphids have been more troublesome initially with control failures against pirimicarb (Pirimor) and omethoate (Folimat) making sticky cotton a real possibility and subsequently nearly a decade later more failures with neonicotinoids. Chemical control failures necessitated a complete re think and modification of the aphid IRMS that is still developing and evolving to this day. The strategy is underpinned by resistance monitoring and mitigation methods based on chemical alternation and no sequential use. This is augmented by a series of adjunct methods of aphid control that help put the resistance gene(s) at a selective disadvantage. Although the newly emerged neonicotinoid resistance in cotton aphid is a serous concern the Australian cotton industry is now much better placed to cope with resistance than back in 1998-1999. With the help of good resistance management Pirimicarb (Pirimor) and omethoate (Folimat) now work and from the 2010-2011 season new chemistry called spirotetramat (Movento) will be available