A widespread problem of premature defoliation and physiological cut out of cotton has occurred in the Emerald Irrigation Area since the early 1980s. The problem was particularly severe in 1988 and 1989. This premature senescence has consistently been associated with a discolouration of the upper leaves towards plant maturity, and also with the leaf spot fungus Altemaria macrospora. Premature senescence can occur and lead to leaf loss even in the absence of leaf spot infection, although defoliation is neither as swift or complete. To enable comparison between visual estimates in the field, a standard scale of the symptom severity has been adopted (table 1). This is usually assessed at a time just prior to the first boll splitting.

Question: When is a cotton plant not a cotton plant? Answer: All the time. Healthy cotton plants are always part of a mycorrhiza.

Documentation of crop yields and varieties in the Toowoomba Royal Agricultural Show Irrigated Crops Competition since 1972 demonstrates the great advances achieved by cotton breeders as new varieties have been introduced to the industry. Data is based entirely on commercial crops entered in the competition on the Darling Downs. Agronomic data for those crops collected since 1987 also provides an interesting documentation of commercial crop management on the Darling Downs. Unfortunately, previous crop history, which influences nutrition inputs, and insecticide applications were not recorded, depriving us of a more complete picture. Crop yields are determined from the field area, precisely measured, required to produce a full module. The module is then weighed and ginned commercially at the ginnery

Cotton production is an increasingly complex business requiring continuous adaptation to changing circumstances. Resilience thinking is an approach designed to understand a complex and changing operating environment and maintain capacity to manage future challenges. CRDC undertook this resilience assessment of the Australian cotton industry at multiple scales to better understand how to best adapt to change and identify critical threats and opportunities for the industry, and strategically target investment and resources. This resilience assessment is structured around the three scales of cotton production in Australia – the farm, the region and whole of industry.

This Guide provides you with a comprehensive summary of the key cotton crop protection issues, and is brought to you by CRDC and the Australian cotton industry's joint extension program, CottonInfo.

During the 1990-91 and 1991-92 seasons planting date experiments were carried out at Narrabri Agricultural Research Station using a range of cotton varieties. These experiments form part of an on-going program to investigate the agronomic performance of new cotton genotypes and they also provide data for the development of crop simulation models. This paper presents the yield results from these experiments and draws conclusions about the most appropriate varieties for planting in various pans of the season.

This study tour and work experience opportunity was undertaken to give the student researcher a broader look at cotton, agricultural technology and general agriculture in America and Canada, in the hope of finding practices or technology to implement into our Australian industry. Whilst on tour, the researcher also attended the 2017 International Food and Agribusiness Management Association (IFAMA) Global Conference and participated in the student case study challenge, placing third globally.

A detailed research tour is documented in the Final Report.

The outcomes on return include the follow-up on implementing plant psychrometers to assess the commercial viability and benefit/gain to the grower and have approached Plant Phytech to conduct a trial this 2018 cotton season on the Liverpool plains. In addition, the researcher will be looking at the practical implementation of precision ag by trialling echelons approach to collecting, interpreting and uploading data without needing the farmer to export or upload data themselves.

Encouraged by a trial 1/2 acre result of 2.8 bales per acre from the 1990 cotton pick, Tandou has grown 70 acres in 1991 and 850 acres in 1992 installing one roller gin to process the 1991 crop and expanding the gin this year to four roller gins with provision to expand to a total of eight. The same Tandou gin also accommodates two saw gin stands with provision for a third.

It is anticipated that the IPM short course will develop sufficient interest, motivation and confidence in growers to implement appropriate IPM strategies. By learning together it is expected that growers will contiriue to communicate regularly in developing their lPM management systems. This will lead to quantifiable changes in farm management involving real adjustment in management of insect pests. There will also be long-term economic benefits and improved sustainability for cottongrowers.

This project supports the ongoing development of IPM in cotton by targeting emerging pest issues, and inappropriate management which may threaten IPM. Key outcomes were:

1. Green vegetable bug (GVB) uses broad leaf weeds as hosts on cotton farms and in refuge areas. GVB prefer to feed and oviposit in legume crops such as mungbean, pigeon pea and soybean. Management of these weeds and crops on farms could influence risks of problems in cotton. Parasitism rates by the egg and nymphal/adult parasites are generally low. 2. Information summarising effects of the new registered compounds (e.g. Shield) and the lower rates of dimethoate has been incorporated into the ‘Impact of insecticides and miticides on predators in cotton’ table in the Cotton Pest Management Guide 2010-11. 3. Leaf damage resulting in reduced leaf area at or after cutout is unlikely to affect yield unless it is high – probably > 50% leaf loss in the upper canopy (top 6-9 nodes). Damage in the boll fill period before cutout may reduce yield. A tentative leaf loss threshold of 30% to 40% could be used. Results are relevant in assessing effects of leaf loss due to locusts and cluster caterpillar. 4. The efficacy and IPM fit of two fungal biopesticides BC639 and BC667 was evaluated. Both reduced abundance of aphids compared with the control by about 10-50% but the results were erratic and slow. However, the bio-pesticides are more selective than most commercial options – hence the conservation of beneficials may be greater. 5 The spread of CBT from the transplant colonies (= ratoon plants) was greater than from the inoculation colonies (= influxes from host outside the field). Transmission rate increased from < 10% with 1-2 aphids to > 50% with 5-15 aphids. If single aphids infest plants the latent period is 3 to 3.5 weeks but could be a little as 9 days with greater infestations. In the latter case, early management of aphids would be required to reduce the risk. 6. Pale cotton stainer (PCS) females are more damaging than males or mating couples. Females caused up to 50% yield loss and reduced germination success when feeding on young bolls. Feeding on older bolls did not reduce boll weight, but did affect boll opening, harvestability and germination. 7. Bemisia tabaci B-Biotype dominated whitefly populations during 2008-09, with virtually no B. tabaci Eastern Australian Natives, few greenhouse whitefly (Trialeurodes vaporariorum) and no B. tabaci Q-Biotype found. Volunteer and ratoon cotton, sowthistle, marshmallow, turnip weed, noogoora burr and paddy melon are hosts through winter. This project provides new information to make better decisions about management of emerging pests. Many outcomes have been delivered to industry through presentations, published resources and the WWW. Benefits to the industry are more rational decisions on the need to control pests and awareness of risks for different control options to obtain a better management balance between control and environment.