Chapter 2 Genetically modified canola
This chapter describes genetically modified (GM) canola and GM crops generally. The first section describes herbicide-tolerant canola; the second section provides a worldwide overview of GM crops. The third section describes GM crops generally in Australia, while the last section describes GM canola varieties in Australia.
2.1 Herbicide-tolerant canola varieties
Canola (Brassica napus L.) is a plant that originated from either the Mediterranean or northern Europe. It is also known as oilseed rape or rapeseed (Warwick et al. 2000). The crushing of canola seed produces canola oil, which is used in margarines, cooking oils and some processed foods such as biscuits, salad dressings, snacks and frozen foods. The byproduct of the crush (canola meal) is used as a feed supplement in livestock diets, mainly pig, poultry and dairy rations (Spragg and Mailer 2007). Demand for canola oil and canola meal (and thus canola seed) has been rapidly increasing in recent years. The canola industry is extremely competitive, and global production has increased by almost 40 per cent by tonnage over the past five years.
To compete globally, canola varieties have been bred to improve yields, reduce costs of production and improve oil content and quality. A particularly important development has been the breeding of herbicide-tolerant crops, which allows chemical based weed control without affecting the crop. In canola, herbicide tolerance has been introduced using both conventional breeding methods and gene technology (see box 2.1).
Box 2.1 What are biotechnology and gene technology?
Biotechnology is a broad term used to describe any technique that uses living organisms or parts of organisms to make or modify products, or improve plants or animals, or to develop micro-organisms for specific uses in industry, technology, medicine or agriculture. Biotechnology is used, for example, in the production of foods and medicines, the removal of wastes and the creation of renewable energy sources.
Gene technology is one of a number of tools used in some biotechnology processes. The generation of genetically modified plants (for example, GM canola), whereby the genes of a plant are modified, is one of a number of applications of gene technology.
Production systems for canola in Australia are largely based on reduced tillage, whereby the land to be planted is sprayed with herbicide to eliminate weeds before seeding, rather than the land being ploughed. Estimates of the costs of weeds in agriculture vary, but one estimate puts the direct financial impact of weeds at $3.5 billion a year, covering both production losses and control costs (Plant Health Australia 2002).
In Australia, the use of herbicide-tolerant canola is a relatively new technology. Conventionally bred herbicide-tolerant canola was introduced into commercial production in 1994 and has been readily adopted by Australian growers. The first commercial herbicide-tolerant canola varieties contained inbred tolerance to triazine herbicides (for example, Gesaprim®). Triazine tolerant (TT) canola varieties were developed by conventional breeding methods from naturally mutated plants found in Canada. The TT canola varieties are less energy efficient than non-TT canola, yielding 10–30 per cent less seed and lower oil content than conventional canola yields (Robertson et al. 2002). Compensating for this lower yield, however, is the ability of growers to better manage weeds and also sow their canola crop earlier (Carmody et al. 2001).
In 2000, canola with inbred tolerance to imidazolinone herbicides (for example, Clearfield®) was introduced. This seed is sold with the herbicide. The Clearfield® trait does not carry the inherent yield penalty of TT canola (Carmody et al. 2001).
The use of herbicide-tolerant canola has produced a major shift in cropping in southern Australia, essentially due to superior weed control (Carmody et al. 2001). Effective weed control can increase yield and thus increase the value of the crop. The use of herbicide-tolerant canola increases the weed management options available to growers, such as using fewer types of chemical and having greater flexibility in timing operations to adjust to variable climatic conditions.
Additional weed management benefits include the chemical thinning of crops, increased seed purity and the ability to cultivate new areas of land where weed problems previously made growing the crop unmanageable and unprofitable. An estimated 80–90 per cent of the canola crop of Western Australia and 30–40 per cent of the canola crop of the remaining states comprise conventionally bred herbicide-tolerant canola (Norton 2003).
2.2 Overview of genetically modified crops worldwide
GM crops have been grown commercially since 1996. In 2006, 10.6 million farmers in 22 countries (11 developing and 11 industrial) planted a total of 102 million hectares of GM crops (James 2006). Argentina, Canada and the United States accounted for 60 per cent of that area. Six countries in the European Union (France, Germany, Spain, the Czech Republic, Portugal and Slovakia) are also now planting commercial GM crops, predominantly insect-tolerant maize. The global area planted to GM crops has increased more than 60-fold over the first 11 years of commercialisation, reputedly making GM crops the fastest adopted crop technology in recent history (James 2006).
In addition to canola, international agricultural commodity markets now accept large volumes of GM crops such as soybeans, maize and cotton (see Brookes and Barfoot 2006a; Fernandez-Cornejo and Caswell 2006; Gomez-Barbero and
Rodriguez-Cerezo 2006; James 2006; Trigo and Cap 2006). In the three years to 2005-06, more than 60 per cent of the world trade in soybeans, maize, canola and cotton came from countries that grew GM varieties (US Department of Agriculture 2007). In the case of soybeans, GM varieties dominate world trade, with only 8 per cent of trade in certified non-GM soybeans (Foster and French 2007).
2.3 Genetically modified crops in Australia
GM cotton, tolerant to herbicides and/or resistant to insects, is the only broadacre GM crop that Australian farmers grow. In 2005-06, Australia produced more than 840 000 tonnes of cotton over 335 000 hectares in New South Wales and Queensland (Australian Bureau of Statistics 2006). The Australian cotton industry is valued at approximately $1.5 billion, with GM varieties making up 90 per cent of all cotton grown. This is the maximum amount of GM cotton that can be grown, given the isolation and trap crops required for sustainable pest management. Apart from cotton lint, the uses of cotton seed almost mirror those of canola: GM cotton seed protein is used in the animal feedlot and dairy industries and as drought feed for cattle, while cotton seed oil is used extensively in commercial cooking in Australia.
The Panel is aware of a number of economic and scientific studies that have assessed the impact of GM crops worldwide on economic, environmental and human health grounds (notably, Brookes 2007; Gomez-Barbero and Rodriguez-Cerezo 2006; James 2006). Appendix 6 provides a detailed account of these reports.
2.4 Genetically modified canola varieties in Australia
In July 2003, the Federal Office of the Gene Technology Regulator (OGTR) issued a licence (DIR 021/2002) to Bayer CropScience Australia, approving the commercial release of seven GM InVigor® hybrid canola lines. InVigor® canola consists of a unique hybrid breeding system using a male sterility gene (barnase) and a fertility restorer gene (barstar), both derived from a common soil bacterium. The InVigor® technology enables production of hybrid seed, which allows increased plant vigour and seed production.
An additional gene confers resistance to the active ingredient (glufosinate ammonium) in the herbicides Liberty®, Basta® and Finale®. The Australian Pesticides and Veterinary Medicines Authority (APVMA) has registered the herbicide Liberty® for use with InVigor® canola crops.
In December 2003, the OGTR issued a licence (DIR 020/2002) to Monsanto Australia for the commercial release of GM Roundup Ready® canola. Herbicide tolerance is enabled by the introduction of two genes from a common soil bacterium. The Monsanto Roundup Ready® GM canola is tolerant to the herbicide glyphosate, which is the active constituent of a range of proprietary broad spectrum herbicides (including Roundup®) registered by the APVMA. Glyphosate is also registered for use in non-selective (general) weed control in broadacre agriculture, horticulture and non-cropped areas (including industrial areas and roadsides), and it is a widely used chemical in all these situations. It kills plants by inhibiting an enzyme in a biochemical pathway for the synthesis of aromatic amino acids. This pathway is not present in mammalian, avian or aquatic animals.
Monsanto Australia has licensed Roundup Ready® canola technology to Pioneer Hi-Bred and Nufarm, and has also sold Nufarm its Roundup Ready® canola germplasm, developed specifically for the Australian market between 1996 and 2003.