A project investigating the molecular and histological effects of silicon application on cotton infected with Fov was inspired by promising preliminary results obtained by Dr Linda Smith (QPl&F) in glasshouse and field trials. Silicon application has been demonstrated to effectively ameliorate or reduce the symptoms of disease caused by fungal pathogens in many plant-pathogen interactions, including those involving host species such as rice, cucumber and wheat. The mechanisms of resistance attributed to silicon treatment include the creation of a physical barrier to pathogen penetration, and the induction of defence responses associated with the increased production of defence related compounds and alterations in defence gene expression. The feasibility of applying silicon to reduce incidence or severity of Fusarium wilt in cotton was investigated utilising two forms of silicon and two cotton cultivars with different resistances to Fov. The following defence responses were assessed with and without silicon treatment:

a. Disease severity and incidence, effect of silicon on nutrient acquisition

b. Histological defence reactions including the accumulation of phenolic compounds and lignin

c. Defence gene changes

d. Defence enzyme activity

As Bion has recently been registered for use by the Australian cotton industry, an additional aim of the project was to ascertain the effects of this chemical resistance inducing agent on cotton infected with Fov. Bion is applied to cotton seed as a seed treatment for the control of both Fusarium wilt and black root rot, whilst it is also commonly applied as a foliar spray to induce defence responses in other plant species. The aim of this research was to determine if defence responses in Fusarium wilt infected cotton, including defence gene expression changes and changes in the activities of defence related enzymes, were affected by Bion treatment; and to determine if these responses were more pronounced following Bion application in the form of a seed treatment or a foliar spray.

The Australian cotton industry has had in place since 1997 a voluntary environmental

management system – its Best Management Practice (BMP) Program – that has successfully

overcome the limitations of a purely regulatory approach to natural resource management. The

BMP Program focuses on the management of pesticides and petrochemicals, soil and water, and

native vegetation.

The industry is looking to build on the success of the BMP Program, and is in the process of

negotiating for it to provide an alternative means for cotton farmers to comply with any existing or

new regulations governing how land and water is managed in Queensland.

Reviews of the BMP Program and of its outcomes highlight that it has led to a decline in

pesticides used on cotton farms, a decline in pesticides found in riverine environments, improved

stormwater management, improved farm management and a reduction in the regulatory burden

on cotton farmers.

This paper will outline the structure of the cotton industry’s BMP Program, highlighting the factors

that have been critical to its success, including a detailed discussion on the rationale behind the

partnership approach, between the industry and regulators, seen as necessary to achieve onground

change. The paper will then touch on the benefits the Australian cotton industry sees in

working with the World Wide Fund for Nature (WWF) on its ‘Better Cotton’ initiative.

The objective of purchasing a Nikon stereo microscope was to improve the capability of identifying

pathogens of cotton. More than 40 samples for diagnosis have been received at the Ecosciences

Precinct laboratory since mid November 2013. The ability to identify pathogens of cotton from

diagnostic samples has been greatly improved due to the magnification range of this instrument (5X–

378X) and ability to attach a camera to photograph pathogen structures such as the various types of

spores produced for use as reference material. Pathogens identified include Fusarium oxysporum f. sp.

vasinfectum, Verticillium dahliae, Alternaria macrospora and Thielaviopsis basicola.

There is also a need for new equipment to successfully identify pathogens of cotton from samples

received from researchers, consultants and growers for general diagnostic enquiries.

Deep drainage is essential for the removal of salts from the reach of crop root systems. The disadvantages are less water which could be used by the crop and the removal of essential nutrients transported the draining water. There are also concerns for the movement of salts and nutrients into groundwater. Shallow water tables that were reported by Willis et. al. (1997) are examples of excessive deep drainage and illustrate the dangers of irrigation on lighter soils.

The performance of the first generation of transgenic (INGARD) plants released in Australia since 1996 was disappointing at a commercial level, despite the considerable reduction in pesticide usage required to grow the crop. This was primarily because of the variable performance of the plants in insect control, either across farms, or at different times of the season. A decline in efficacy had previously been noted at the end of the season, but many cases of serious decline in insect control have been reported much earlier, requiring immediate spraying to control insect outbreaks. This decline in expression appears to be a consequence of the decrease in the activity of the 35S promoter driving the INGARD gene probably in response to either environmental or physiological influences on the plant. These problems cannot be corrected in the short-term using gene technology and we must rely on our breeders to select for individual plants that show more robust expression from the promoter driving INGARD. Monsanto has been able to resolve some of the problems with INGARD in their second generation Bollgard II cotton with higher levels of expression of the Cry2Ab gene. In the longer-term, for new biotech products, we can try to find better promoters that will express throughout the season or that at least are stronger during the period when the INGARD gene starts to decline. New gene constructs could then be developed that will either complement the existing genes or replace them and the same promoters could be used in conjunction with a number of other genes in the biotechnology pipeline. Using new genomic technologies we have identified a couple of possible promoters that might show the desired pattern of expression throughout the season, but they need to be fully evaluated in transgenic cotton plants. One promoter from a photosynthetic gene has been developed into gene constructs and introduced into both an easily engineered model plant and also into transgenic cotton, so that we can test its performance under field conditions. All the data is not yet to hand, but we hope that this, and other promoters to be analysed later, will give robust field expression in transgenic cotton and add to our toolkit of genes and pieces of genes from which we can develop more robust transgenic products for the cotton industry as well as provide biotechnologists with a greater selection of promoters to produce new biotech products.

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.