43. The receiving environment forms part of the context in which the risks associated with dealings involving the GMOs are assessed. This includes: any relevant biotic/abiotic properties of the geographic regions where the release would occur; intended agricultural practices, including those that may be altered in relation to normal practices; other relevant GMOs already released; and any particularly vulnerable or susceptible entities that may be specifically affected by the proposed release (OGTR 2009).
6.1 Relevant abiotic factors
44. The abiotic factors relevant to the growth and distribution of commercial cotton in Australia are discussed in The Biology of Gossypium hirsutum L. and Gossypium barbadense L. (cotton) (OGTR 2008). To summarise, factors restricting where cotton can be grown in Australia are water availability (ie irrigation or rainfall), soil suitability and, most importantly, temperature. Cotton seedlings may be killed by frost, and a minimum of 180 frost-free days of uniformly high temperatures (averaging 21-22°C) are required for crop growth. Growth and development of cotton plants below 12°C is minimal and a long, hot growing season is crucial for achieving good yields.
45. The size, locations and duration of the proposed limited and controlled release are outlined in Section 3.2. The proposed dealings involve planting GM cotton in established farmlands in the LGAs of Narrabri, NSW, Wyndham-East Kimberley, WA, and Central Highlands, Qld. Rainfall and temperature statistics representative of these planting areas are given in Table 1.
Table 1. Temperature and rainfall data representative of proposed release sites*
|LGA||Weather station||Mean temperature (C°)||Mean monthly rainfall (mm)|
|Summer max.||Summer min.||Winter max.||Winter min.||Summer||Winter|
|Shire of Wyndham-East Kimberley||Kimberley Research Station||36.3||24.6||31.5||15.1||185.3||2.8|
|Narrabri Shire||Narrabri West PO||33.3||18.7||18.8||4.5||74.0||45.2|
|Central Highlands Region||Emerald PO||34.1||21.0||23.3||7.8||98.0||27.8|
*Data were taken from the Australian Bureau of Meteorology website. Temperature and rainfall data are an average of at least 40 years of records. Summer entries are averages of monthly data from December to February, and winter entries are averages of monthly data from June to August.
6.2 Relevant biotic factors
46. The biotic factors pertaining to the growth and distribution of commercial cotton in Australia are discussed in The Biology of Gossypium hirsutum L. and Gossypium barbadense L. (cotton) (OGTR 2008). In addition, the following points are of particular relevance to this release:
- Narrabri Shire and the Central Highlands Region are commercial cotton growing regions, whereas cotton is an experimental or occasional small-scale crop in the Shire of Wyndham-East Kimberley
- Insect resistant and/or herbicide tolerant GM cottons constitute the majority of Australia’s cotton crops (see Chapter 1, Section 6.4).
6.3 Relevant agricultural practices
48. The limits and controls of the release are outlined in Section 3.2 and 3.3 of this Chapter. With regard to the agricultural practices, the GMOs proposed for field release would be planted with a standard cone seeder and grown following standard cotton agricultural protocols. Herbicides applied to the GM cotton fields would include the herbicides to which the GMOs are tolerant and other herbicides commonly used in commercial cotton cultivation. Part of the trial may assess the efficacy of the introduced insecticidal proteins against the target pest, Helicoverpa armigera (cotton bollworm), under Australian conditions. Introduced infestations of Helicoverpa armigera larvae would be contained inside mini-cages and destroyed prior to harvest.
6.4 Presence of related plants in the receiving environment
49. Commercial cotton cultivation is established in the Narrabri and Central Highlands regions. Experimental cotton crops have been grown for over a decade in the Ord River Irrigation area in the shire of Wyndham-East Kimberley.
50. Data on the commercial cultivation of cotton in Australia are discussed in The Biology of Gossypium hirsutum L. and Gossypium barbadense L. (cotton) document (OGTR 2008). Cotton commercially grown in Australia is predominantly G. hirsutum species.
51. Herbicide tolerant and/or insect resistant GM cotton plants are used widely in commercial cotton production. Over 95% of Australia’s cotton growers planted GM cotton in the 2007/08 season (Cotton Australia website). For a list of relevant approvals for commercial releases of GM cottons in Australia, see Section 7.1.
52. In southern Australia, ephemeral populations of cotton may be present outside of cultivation. Cultivated cotton can persist as a perennial plant in tropical areas and small populations of naturalised cotton (G. hirsutum and G. barbadense) exist in northern Australia, particularly in areas associated with a prolonged supply of fresh water (Hnatiuk 1990). The majority of naturalised cotton populations occur in the Northern Territory and eastern Queensland (Australian Virtual Herbarium).
53. There are 17 native species of Gossypium in Australia, most of which can be found in the Northern Territory and the north of Western Australia (OGTR 2008). G. australe is the most widely distributed species, occurring from the east to west coast of northern Australia (Australian Virtual Herbarium). The native Gossypium species prefer well-drained sandy loams and are rarely found on heavy clay soils favoured by cultivated cotton (OGTR 2008). Generally, they are found in native vegetation and not in disturbed/modified habitats such as agricultural areas (Groves et al. 2002).
54. Well established genetic incompatibility prevents crossing of native cotton species with cultivated cotton in the natural environment (discussed in OGTR 2008).
6.5 Presence of the introduced genes or similar genes and encoded proteins in the environment
55. The introduced genes for insect resistance were originally isolated from Bt. Bt is a common natural soil bacterium in Australia. For several decades, the use of microbial Bt formulations in products for insect control has resulted in occupational exposures of agricultural workers (e.g. inhalation of sprays), smaller-scale exposure in domestic gardens, and dietary exposure through consumption of Bt-treated fruit and vegetables. For a decade, commercial GM cotton plants containing Bt genes have also contributed to the levels of Bt genes in agricultural areas of Australia. For these reasons, Bt insecticidal genes and their encoded proteins are ubiquitous in the Australian environment.
56. The introduced genes for herbicide tolerance were derived from organisms that are widespread in the Australian environment. The antibiotic resistance selectable marker gene was isolated from a common bacterium.
57. Additional information relevant to the presence of the herbicide tolerance and antibiotic resistance genes in the environment is covered by CCI. The confidential information was made available to the prescribed experts and agencies that were consulted on the RARMP for this application.