This project funding supported two workshops held in the Upper Namoi area; one in Spring Ridge, and one in Boggabri. The objectives of the workshops were twofold; 1) To provide opportunity for both cotton growers and others in the farming system to hear firsthand about the best practices of spraying to offset risk of direct or indirect spray drift

2) Increase industry awareness about the consequences of drift/inversion and safe herbicide application

The workshop aims to reiterate changed to the new legislation for the application of 2,4-D over the summer spray period, spray drift risk management and best practice spray application.

The 1998-2003 strategic plan of the Cotton Research and Development Corporation (CRDC) set

research goals in three main areas: (i) sustainability, (ii) profitability and competitiveness and (iii)

people and communities. This study contributes to the last of these areas by developing a framework

for monitoring the socio-economic impacts of the cotton industry on people and communities in the

cotton growing regions. The specific aims of the study are to:

1. identify long term trends in the cotton industry that are likely to show socio-economic impacts in

the cotton growing regions,

2. identify the main linkages between the cotton industry and the regional economies in the cotton

growing regions,

3. gain an appreciation of the socio-economic impacts that are currently being experienced in the

cotton growing regions due to changes in the industry, and

4. identify the important socio-economic impacts that the industry will need to monitor in the medium

term, and propose appropriate socio-economic indicators to do this.

Pressures on the Industry

The cotton industry faces global competitive pressures as do many other primary industries. Within

Australia, cotton production appears to be stabilising in some regions, such as the Gwydir and Namoi

valleys, while it continues to increase in others. Cotton research and development has played an

important role in the introduction of new transgenic cotton varieties, the steady increases in yields and

the improvements in management that are underpinning productivity growth. Management is

becoming more knowledge-intensive, while the demand for spraying and chipping services is

decreasing. The availability of irrigation water will remain an important issue for the industry.

Growers have already made significant adjustments to improve water efficiency and this can be

expected to continue in the medium term. The economic and social changes occurring within regional

economies and communities can no longer be understood solely in terms of the changes occurring in

primary industries. This means that care has to be taken in identifying changes attributable to the

cotton industry. The causes of these changes are clearest where cotton dominates agricultural

production and the size of the non-farm economy is relatively small. In other areas, broader changes

in community aspirations, retailing and transport may result in social and economic impacts that

outweigh any effects of the cotton industry. Compared to most other agricultural industries, however,

the cotton industry with its input and knowledge intensiveness and local processing is more likely to

have impacts on regional economies.

The report provides a detailed description of a series of surveys and reviews, supported by basic

research, through which indicators in the areas above can be regularly measured.

The greenhouse effect is widely considered one of the major threats to Australia agriculture. There is increasing evidence that carbon dioxide, methane and nitrous oxide concentrations are reaching levels that will cause a significant warming of the earth’s atmosphere over the next 10 to 100 years causing great changes in seasonal weather patterns. Forecasts in Australia suggest a reduction in rainfall in the interior regions and increased incidence of drought. If a concerted effort is made to reduce global greenhouse gas emissions, these changes can possibly be avoided.

Cotton is one of many agricultural industries heavily reliant on nitrogenous fertilizers to maintain high levels of production. The inclusion of legumes also provides a boost to the nitrogen economy of the system. Surplus nitrogen is a direct contributor to nitrous oxide (N2O) emissions which has a Global Warming Potential (GWP) approximately 300 times that of a single molecule of carbon dioxide (CO2). Reducing N2O emissions from cropping systems has been widely identified as the highest priority in greenhouse gas abatement in crop production and for ensuring profitability through enhance N and water use efficiency.

The project is the first dedicated analysis of greenhouse gas emissions from soils in cotton based farming systems and its relationship to sustainable cropping practices. Field based estimates of greenhouse gas emissions, specifically nitrous oxide, from an alkaline grey clay under cotton receiving up to 200 kg N/ha of fertiliser, ranged from 0.5 – 2.2 kg N/ha during the 10 week period after the first irrigation. On average only 0.35% of the nitrogen applied as fertiliser was emitted as N2O, which is low compared to global estimates of emissions from fertilisers. Emissions increased to over 1.5% of applied nitrogen when 300 kg N/ha was added, which surpasses the IPCC’s estimated value of 1.25% for deriving N2O emissions from fertiliser sources. Laboratory and simulation studies carried out within this project indicate N2O emissions equivalent to 3% of applied fertiliser nitrogen for a range of clay soils from across the industry.

More field data is urgently needed to ensure current and future management practices are tailored to minimise emissions and maximise nitrogen and water use efficiency. A continued shift to sustainable farming practices, reductions in fallow periods and rotation crops will provide a win-win situation to the cotton and associated industries. This will include enhanced carbon sequestration (and fertility) of soils and a significant reduction in the amount of nitrogen fertiliser which is left unused in the soil profile and potentially lost to the atmosphere as nitrous oxide. More efficient nitrogen management will reduce emissions and increase profitability whilst contributing to the abatement of climate change and its impact on Australian agricultural systems.

Unispray have developed a new centrifugal energy nozzle, the "Unimiser", for the aerial application of

pesticides. The new nozzle is designed to substantially resulting from the

aerial application of pesticides in the cotton industry. The nozzle was designed to generate a very low

range of droplet sizes, (having a relative span of less than 0.8 compared with 1.2 -1.6 for most

currently available nozzles) and a volume median diameter of 250 pm,

Testing of prototype models have demonstrated that that the Unimiser nozzle is able to generate a

narrower range of droplet sizes, as indicated by a lower span, than any other commercially available

alternative. It is expected that drift from this nozzle is likely to be lower than for other nozzle used on

aircraft in the cotton industry.

During the course of this project Unispray decided to initially concentrate on a Helicopter version of the

initial prototype. The results from the single flight line deposit measurements showed that there was a

consistent area of low deposit beneath the centre-line of the helicopter. Since it was impractical to

mount an air driven rotary nozzle in the slow moving air close to the airframe beneath the centre line of

a helicopter, a small number of additional hydraulic nozzles were fitted. This small modification

improved the uniformity of the deposit. The tests showed that more uniform ground deposit patterns

were obtained when three Unimiser nozzles were operated on each side of the helicopter.

Based on results from the wind tunnel studies, pattern testing and market requirements, Unispray

decided to concentrate on a "retro fit" version that can easily be added to existing Micronair units.

Droplet size was measured over the range of nozzle rotational speeds, liquid flowrates and airspeeds

that are likely to be encountered in the field. Testing was initially undertaken with water only but was

later repeated with a Water + 0.1% Agral mix. The Agral was added as it is oflen considered to be

more representative of an actual tank mix. In general a slightly larger range of droplet sizes (larger

span) was generated with the Water + Agral mix. From the measurements a regression analysis was

undertaken to enable prediction of droplet size using the range of variable tested in the wind tunnel

From this analysis an EXCEL based "nozzle calculator" was developed and a full working copy of the

calculator has been included with this report.

The commonly used Micronaire value for cotton is related to both fibre fineness and maturity. There is a need for a new measurement technique to separate these. This is of particular importance to the Australian industry where varieties of fine mature cotton have the potential to be wrongfully discounted commercially by misinterpreting a low Micronaire value as indicating immaturity in a coarser fibre.

This project extends the work of a previous CRDC funded project (CWT 4C). The earlier project demonstrated that a new approach using an instrument called the Sirolan-Laserscan is able to measure the fineness of cotton fibres independent of fibre maturity. Further, using the experimentally measured fibre fineness value, a process for mathematically 'unravelling' the Micronaire value has been demonstrated leading to accurate fibre maturity values.

The current project aimed to simplify the instrument and increase its speed with a view to matching the speed of the current HVI systems.

A new prototype instrument was designed, built and tested. The results to date are positive. The computer controlled instrument can measure the fineness and maturity of cotton samples and is currently undergoing further testing.

More than 2000 cotton industry personnel (including growers, spray operators, consultants

and spray contractors) participated in spray application workshops conducted throughout all

cotton growing areas. The workshops were organised at a local level and dealt with a range

of topics including setup for endosulfan; nozzle selection and setup; drift management;

weather conditions and spray targeting.

Most CRC Extension Team members attended one of the 2-3 day spray application

workshops to build their skills in this area and to allow them to deal with sonic spray issues

in their own local areas. The Extension Team is a primary contact source at the local district

level and a number of IDO's subsequently conducted their spray application workshops.

Key indicators of the success of the project include:

The workshops dealing with setup for endosulfan had to change the thinking of the whole

industry in relation to the droplet size being used for insecticide application. For years the

push had been to use small droplets but overnight the industry had to embrace the concept of

"medium" spray quality.

• Since the start of the project there has only been 8 samples with endosulfan concentrations above the export tolerance for beef (down from 229 in 1998/99) (National Residue Survey 1995-2002)

• The incidence of samples with reportable endosulfan residues has dropped from 21% to 1.2%.

The project confirmed the continued superior performance of flat fan nozzles (in relation to

newer ingestion active insecticides). These nozzles help to overcome some of the off target

losses associated with drift and evaporation compared to hollow cone nozzles.

• Use of flat fan nozzles for insecticide application is becoming the norm. More than 85% of ground applications are carried out using flat fan nozzles. (Cotton benchmark Survey 2001)

• Sales of hollow cone nozzles have decreased with an increase of flat fan types of featured during the workshops including drift reducing types ( as proscribed on the endosulfan label), conventional flat fan s and twin jet types.

The issue of weather- conditions and spraying was a focus at most workshops. Growers and

applicators are more aware of the issues and monitoring conditions as part of all spray

operations.

• Records are kept for 100% of spray applications. With 75% of respondents using the SprayLog. (Cotton benchmark Survey 2001)

• More than 6000 copies of the SprayLog record book have been distributed in the last three year.

Cotton production in Australia is vitally dependent upon the safe and efficient application of

pesticides. Timely and of insecticides, often only possible using aircraft, is required to maintain adequate control of pest species such as heliothis spp. However if pesticide droplets are transported downwind away from a sprayed area, significant contamination of susceptible areas can occur. For example, contamination of pastures due in part, to endosulfan spray drift, led to significant disruption of the Australian beef cattle industry during 1998.

Previous research (Woods et al. 2001), quantified typical downwind insecticide deposition

profiles for ultra low volume (ULV) and low volume (LV) application of insecticides and

showed that a combination of application parameters could reduce spray drift values. Subsequent to this work, the Australian Pesticide and Veterinary Medicines Authority (APVMA) introduced a regime for the 199912000 cotton season that stipulated that the insecticide endosulfan should be applied by aircraft using Large Droplet Placement (LDP) techniques. Fundamentally, this application technique specified the application of sprays from agricultural aircraft using droplets with a Volume Median Diameter (VMD) greater than 250 pm, water volumes greater than 30 Llha and the use of spray booms where the distance between the two outermost nozzles did notexceed 65% of the wingspan. Used in conjunction with appropriate management strategies, it was postulated that a droplet spectra with a VMD greater than 250 pm could reduce downwind drift levels as a result of the inherent higher droplet sedimentation velocities.

LDP technology requires the use of relatively large water volumes (30 Llha and above)

compared to ULV (3-5 Llha). However aqueous droplets can evaporate rapidly, particularly

when conditions are hot and dry (eg. >30•‹C and RH < 40%). As droplets evaporate they become smaller and may travel longer downwind distances thus increasing the potential for spray drift. One solution is to add an anti-evaporant adjuvant (AEA) to the formulation. Many materials are available which are capable of modifying pesticide behaviour eg. wetters (surfactants which increase droplet spreading and penetration), thickeners (which increase initial droplet size) and stickers (which help droplets adhere to leaf surfaces). Most AEAs are thought to work by adding a skin to the water droplet thereby slowing down the rate of evaporation. There are many claims made regarding the ability of such adjuvants to modify the spray drift behaviour of pesticides.

Some claims are unsubstantiated and rigorous evaluation is required. With increased reliance on water based application from aircraft there is thus a need to investigate the evaporative process and optimise LDP technology for the aerial application of insecticides in cotton.

This project was therefore undertaken to quantify the performance of aircraft nozzle systems,

establish if any, the reductions in spray drift resulting fiom the adoption of LDP technology,

quantify the influence of certain adjuvants and investigate the impact of atmospheric stability on the downwind dispersal of droplets.

Along with length, strength, micronaire and leaf content, the colour grade of cotton is a critical component of the set of characteristics used to assess the overall quality of a sample of cotton, and thereby determine its value. The current ‘base grade’ for colour for Australian cotton is Middling (31). If the colour grade falls to even the next lower grade of Strict Low Middling (41) then a significant discount to the value of the cotton will be applied. Wet, cloudy weather at harvest, a factor beyond a grower’s control, is one of the main causes of deterioration in the colour grade. The extent of the impact of wet weather on colour grade may also be influenced by a range of factors including presence of honey dew, the type / source of the honey dew, crop architecture, crop stage (degree of boll opening), amount of sunshine following the wet and cloudy weather that the crop is exposed to, trash levels in the seed cotton, the moisture of the lint when harvested and the length time between harvest and ginning.

Honeydew studies conducted as part of CSP 1401 “Enhancing IPM in cotton systems” provided information on honeydew characteristics and behaviour under various weather conditions and was followed by a pilot study on the effect of rainfall on cotton colour during 2015/16. This study showed that extended exposure of cotton to rainfall had a marked negative effect on colour. The two-year project herein was developed to continue research into the factors affecting cotton colour in the field and reports on the results of the pilot project and further investigations into the impacts of weather, sooty mould, fungicides and effects on yarn quality.

Industry Development Officer (IDO) of Gunnedah is part of the National Extension Service. This position has been successful in increasing technology adoption by local growers. As well as playing a role in national extension activities, the position has also worked with local growers and consultants to develop extension programs focusing on local production issues.

Large scale farm trials / demonstrations, grower groups under the charter of local area wide insect management form a critical component of extension activities. The promotion of BMP to growers and the local community are also key components of this position. The position provides strong links between growers, consultants, researchers and the wider community.

The Australian industry efforts were reviewed by Dr Patrick Colyer, a plant pathologist with extensive experience in cotton, from Louisiana State University, USA. The Australian Cotton CRC, CRDC and CSD supported Dr Colyer's trip. Dr Colyer arrived in Australia on Saturday 9'" February 2002, to begin a 'tour' through Fusarium-infected cotton growing areas. Along the way, he met and spoke with cotton growers, researchers, seed companies, and consultants. Starting in Narrabri, he met up with CSIRO breeders, the pathologists at ACRI, and toured the CSD seed production facility. Meetings followed this with Deltapine breeders, growers and co~lsultantsin the Goondiwindi and Pampas areas. The tour continued with farm visits and meetings with researchers at QDPI, Toowoomba, and in Brisbane. After a weekend of relaxation on a stretch of the Queensland coast, Dr Colyer participated in the Biotechnology and Fusarium reviews on the 18"' and 19"' of February. Though not knowledgeable in the area of molecular biology, Dr Colyer was able to contribute to general discussion during the Biotechnology review and played a part in the discussion during the Fusarium review.