Sorghum is extremely attractive to ovipositing heliothis (Hencoveipo armigero) moths. Some cotton growers on the Darling Downs are intercropping cotton with sorgum because they believe that sorghum may act as a beneficial nursery, and that the beneficials may move into the adjacent cotton. Here we report on a trial comparing the levels of heliothis egg parasitism and predator abundance in cotton adjacent to intercropped sorghum. The heliothis egg parasitoid Trichogramma pretioswm was released into half of the sorohum, and the levels of egg parasitism in the adjacent cotton were compared between the release and non-release sections of the field.

The maintenance of biodiversity in intensively farmed landscapes in Australia relies mainly on small patches and linear strips of native vegetation - what's been left behind to delineate paddock and property boundaries, alongside roads and stock routes, where soils were unsuitable for farming, or wherever landholders wanted to retain trees. The agricultural matrix itself provides some habitat opportunities but these are limited, especially in areas where irrigation is used.This project set out to answer the simple question: what is more important for the conservation of insect and spider biodiversity in these landscapes -is it the amount of native vegetation, where that vegetation is, or the condition it is in? As with all ecological studies, the question is simple but the answers are complex. Taking three &quote;typical&quote; cotton landscapes that included either or both irrigated and dryland cropping systems, we sampled arthropods and analysed the species richness and functional diversity of the ants, and the morphospecies (identifiable as distinct species but not named) diversity of all other arthropod groups. We used 2 sampling techniques: pitfall trapping and suction sampling of arthropods from ground vegetation. We also recorded vegetation condition and local habitat variables, and calculated landscape metrics based on the proportions of major land use types within circular zones of 100, 500 and 1000m radius of sampling sites. On average there were no differences between landscapes in vegetation condition. However, condition was significantly higher in linear strips than in patches in the medium native vegetation landscape, with this trend being reversed at higher levels of native vegetation. This is almost certainly due to the impact of livestock grazing, which is more diffuse at higher levels of native vegetation, and more or less absent at lower levels.Different components of the arthropod fauna appear to respond in different ways to what happens in the landscape, so there is no &quote;one size fits all&quote; answer to the question posed above. Ant assemblages were different in each landscape, but did not respond to the type of habitat they were found in, e.g. discrete patches or linear strips of vegetation. Similarly, other ground active arthropod groups showedno habitat specificity, and differences werefound only between the verylow (Jandowae) and low (Broadwater) native vegetation landscapes. Arthropods in the ground vegetation did respond to the amount of native vegetation in the landscape, although these relationships were not statistically significant. They also responded to habitat type, but only at the high native vegetation landscape, Callandoon, where irrigation infrastructure (dams, channels etc.) is thought to be responsible through removal of marginal habitats.There was a clear pattern of change in the ants within crops during the growingseason. Some species persist in the paddock during fallow seasons, and this might be assisted by stubble retention and no---till practices.Strategic management of retained native vegetation in intensively farmed landscapes such as these, including narrow roadside strips, can provide essential habitat resources for a range of biota, including arthropods that deliver ecosystem services of benefit to both production and conservation.

The Australian Cotton Production Manual 2013 is a critical reference tool for cotton growers. The manual is a one-stop-shop for growers, outlining all the various decisions that need to be made on-farm in preparation for, and during, cotton production. The manual provides an understanding of cotton physiology, and discusses important considerations for both productivity and profitability.

The Australian Cotton Production Manual is published by the industry’s joint CottonInfo team and is updated each year to incorporate consistent improvements in industry best practice.

Mortality of Helicoverpa in Bollgard II® cotton fields and implications for Bt resistance management Final report To prolong the utility of Bollgard II® against H. armigera, growers that use this tool must follow a resistance management plan (RMP). This strategy is largely based on information from studies of the ecology and population genetics of H. armigera, and the outputs of computer simulation models that use biological information to predict the likelihood of resistance under different scenarios. These models assume that any individuals which are resistant to Bollgard II® survive to successfully reproduce in cotton landscapes. In this project we developed novel methods to determine in the field how natural enemies in Bollgard II® versus unsprayed refuge crops affect the probability that Helicoverpa armigera will survive from hatching until adulthood. Part of this objective was testing how the application of pesticide in Bollgard II® fields to control sucking pests affects natural enemy communities and, in turn, survival of H. armigera. A secondary objective was to co-ordinate the collection of surviving Helicoverpa larvae from Bollgard II® crops and rear them for inclusion in the Bt resistance monitoring program. Survival of Helicoverpa larvae differed significantly across the main crops employed in the current Bollgard II® landscape but the particulars of this trend differed among small and medium larvae. Survival of small larvae was greater in pigeon pea and Bollgard II® cotton that was sprayed for sucking pests and mites compared with conventional cotton and unsprayed Bollgard II® cotton. However, this trend held during mid and late season but early in the season there was no difference in survival across the crops. Survival of medium larvae was greater in pigeon pea compared with conventional cotton and unsprayed Bollgard II® cotton and this trend was consistent across the period during which these crops are attractive. The similar survival in unsprayed Bollgard II® and conventional cotton is intuitive based on past work showing similar communities of natural enemies in these crops. The higher survival in pigeon pea (for both size classes) and Bollgard II® cotton that is sprayed (for small larvae) suggests that these crops may have fewer natural enemies compared with unsprayed Bollgard II® and conventional cotton. The survival results also suggest that spraying Bollgard II® fields for mirids and mites may reduce the abundance of natural enemies (relative to unsprayed Bollgard II® fields), and that this process affects mortality of smaller larvae. It is possible, for example, that sprays reduce numbers of predators that specialise on small larvae. These suggestions are supported by data on arthropod communities across replicate fields. In particular, spiders appear to play a significant role in mortality. For small and medium larvae there was a strong negative relationship between survival and abundance of spiders in open tents but not with any other category of predators (arthropods <5mm, arthropods 5mm or >, ants, ladybeetles) or parasitoids. Moreover, across replicate fields the abundance of spiders mirrored the mortality of larvae in open tents in the same crops. For small larvae there was a strong positive relationship between survival and the abundance of small non-predatory arthropods. In addition, across replicate fields the abundance of these arthropods opposed the mortality of larvae in open tents in the same crops. These results suggest that alternative small prey may improve survivorship of small larvae.During the past three seasons, surviving larvae were found in Bollgard II® fields on some properties in all main cotton valleys. We determined (through collaboration with CSE112) that Bt resistance, or the absence of Bt proteins in the host or surrounding plants, is not the mechanism allowing these larvae to survive on Bollgard II®. This information will be utilised in an upcoming forum to assist with reviewing the current Resistance Management Plan for Bt cotton.

Central Queensland (CQ) has had a long history of cotton production, with a modern industry spanning over 30 years. The hot tropical climate of CQ presents both constraints and opportunities for cotton production. Production constraints have traditionally included more severe insect problems and weather-related stresses relative to cooler growing areas. Grower records show that over the last 30 years cotton yields and profitability vary dramatically between seasons, among farms and even fields within farms. Reasons for this high variability are thought to include external factors such as variable weather conditions and variable crop management practices. On the flip side, the warm climate translates into a relatively long growing season, which in turn facilitates flexibility in sowing times and opportunities for compensatory yield.

This project continued CRDC sponsorship of a development extension officer in a co funding arrangement with DPI&F in Queensland. An industry-sponsored review of the national extension effort for cotton determined such positions should actually reside within the State Departments of Agriculture.

Drainage from below the plant root zone is not only a waste of water resources but a potential driver of rising water tables and salinity. Better estimates of the quantity and timing of drainage are required in the clay plains of the northern Murray Darling Basin to improve understanding of drainage processes, in particular under irrigation. This will allow better assessment both of how and where improvements can be made in irrigation management and of the risk of salinity. Current drainage estimates are based on indirect measurements - such as chloride mass balance - or on calculations using measurements or estimates of other components of the water balance. Both approaches lead to large uncertainties in drainage estimates. Direct measurements of drainage are difficult because most instruments disturb the hydraulic gradient in the soil, which is the main driver for drainage, and therefore affect the amount of drainage measured.A variable tension drainage lysimeter was built at the Australian Cotton Research Institute near Narrabri to provide accurate measurements of drainage under an irrigated cotton-wheat rotation on a Grey Vertosol typical of the region. Such lysimeters are designed not to disrupt the hydraulic gradient by being 'hydraulically invisible' so as not to interfere with the rate of drainage. The lysimeter consists of an array of six steel boxes whose upper surface is made of a porous, sintered steel sheet that, once saturated, allows water to flow but can hold a vacuum of up to 32 kPa. The boxes were installed at 2.1 m depth via tunnels excavated horizontally from a concrete access shaft. Thus the soil over the trays is undisturbed. The trays cover an area of 1.8 x 0.9 m. A method of preparing the soil on the ceiling of the tunnel was developed that uses a resin peel to remove any smearing. A contact material to connect the upper surface of the tray to the soil ceiling was designed and manufactured by grading silica flour.The system mimics the hydraulic gradient in the soil by regularly measuring the soil water potential at 2.1 m depth with tensiometers and then applying a vacuum equal to this potential to the inside of the trays. A data logger continuously adjusts the vacuum to the soil water potential. Water in the soil above the trays therefore experiences the same hydraulic gradient as if the trays were not there and flows at the same velocity into the trays. The trays have sloping floors which direct the water to a drain and thence to cylindrical collection vessels that are continuously weighed allowing the rate of drainage to continuously measured. The system is designed to be fully automated.Apart from providing accurate measurements of drainage over time, the lysimeter will be used as a benchmark against which to test other simpler - and less expensive methods - that can be deployed in a wider range of situations. Barrel lysimeters, wetting front detectors, and instruments to measure other water balance components have been installed near the lysimeter. Chloride mass balance measurements are also regularly made nearby.In addition, the data from the lysimeter will be used to improve water balance models that provide the only way of estimating the long-term drainage of current and alternative management systems for a variety of soil and climatic conditions.

Australian cotton is purchased for a premium as it meets spinner's requirements on the basis of quality and consistency. Coarse (high micronaire) fibre, high nep counts and excessive short fibre content are aspects of Australian cotton that spinners would like to see improved. Fibre quality in the field is affected by a large number of interacting factors: variety, seasonal conditions, crop and harvest management. This project continues explicit and important research employing a combination of both in-field and post-harvest research efforts to improve the quality of Australian cotton, key strategies of both the CRDC and CRC. Improving the understanding of the links between agronomy and textile performance will allow us to better refine in-field crop management recommendations to ensure cotton produced meets or exceeds market expectations.Specific objectives were to: (i) Improve the understanding of the effects of crop stress on micronaire and its components fineness and maturity. (ii) Reduce neps in the field through development of monitoring approaches to identify instances where crops have an increased risk of neps. (iii) Identify management practices that improve the consistency of cotton taken from the field. (iv) Conduct research to establish the value (price and textile value) of blending/segregation of lint quality based on quality attributes. (v) Identify other unique fibre quality attributes of Australian cotton to enhance its market value. (vi) Maintain research capability and activities into fibre quality research from the 'field to fabric'. This project was successful in providing new knowledge on fibre quality issues through:- Improved understanding of the changes in crop management practices and climate that affect micronaire and its components of linear density and maturity.- A new methodology to predict micronaire using temperature

This project has addressed issues that have emerged with the widespread adoption of Bollgard II cotton, and the resulting reduction in insecticide use.

The Rural Water Use Efficiency Initiative ran from July1999 to June 2003. The key achievements were:Greater than 75% awareness and participation in the program Cotton and grain irrigators investment of $3.6 million with a government contribution of $1.5million 78% of cotton irrigators had become involved in Cotton BMP by August 2001A 12.8% increase in water use efficiency (equivalent to ~ 60 000 ML). An increase in GPWUI ranged from 45% to 55% and the change in IWUI ranged from - 11% to 30% shown below when compared to the baseline for WUE in the Australian Cotton Industry was determined by Tennakoon and Milroy (2003).