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Interview with Christopher Preston

Genetically modified canola in Australia: "Coexistence is a question of the market."

Since 2008, genetically modified (GM) canola has been cultivated commercially in two Australian states. How the coexistence of GM and conventional canola cultivations has been managed was the subject of an interview between BioSafety and Dr. Christopher Preston, Assistant Professor for Weed Management at the University of Adelaide.

The area of cultivated GM canola increased from 9500 hectares in 2008 to 41 000 in the 2009/2010 season. This corresponds to about 10 – 15% of the area of canola in the two states. The seed industry and the government have agreed on certain voluntary measures to enable growers to choose which type of canola to grow. These comprise, among others, training courses for farmers growing GM canola on how to avoid an uncontrolled spread of GM canola and minimum distances between fields with GM and conventional canola.

Dr. Christopher Preston is an expert on weed control at the School of Agriculture, University of Adelaide. He has taken an active part in the public debate on the introduction of GM canola varieties in Australia. In his opinion, it will be the market that decides on whether Australia will still produce conventional canola in the future. Coexistence is in principle possible.

Canola (Canola) in Australia: Herbicide-tolerant varieties are predominantly grown. In 2008, the GM Roundup Ready canola variety was introduced. The seed industry developed guidelines for cultivation, to make coexistence with conventional canola possible. In Australia, conventional canola is allowed to contain up to 0.9% of GM components. For conventional canola seed a limit of maximally 0.5% of GMO fraction has been specified
Photo: Australian Government Department of Agriculture, Fisheries and Forestry

GMO Safety: Dr. Preston, why is GM canola grown in Australia?

Christopher Preston: The GM canola that has been cultivated since 2008 in the two States, New South Wales and Victoria, exhibits herbicide tolerance. Varieties of canola that are tolerant to herbicides are not new in Australia. Since we have big problems with weeds in canola cultivation, cultivation of canola in Australia has only significantly expanded after the introduction of herbicide-tolerant types of canola. This has made weed control very effective. Today, canola is, after wheat and barley, the third most important crop in Australia. Triazine-tolerant canola varieties have been grown since 1993, and imidazolinone-tolerant cultures since 2000. Both are conventional canola varieties. Now we have a genetically modified canola variety that is tolerant to the herbicide glyphosate. A further GM canola variety that is tolerant to the herbicide glufosinate has also received approval, but is not yet being cultivated. With these new GM varieties, we can use additional herbicides in canola cultivation. Through rotation of herbicide tolerant canola types we can slow down the emergence of herbicide-resistant weeds.

GMO Safety: What experience is already available on the coexistence of GM and conventional canola?

Christopher Preston: The introduction of GM canola and the corresponding measures for coexistence were a challenge in Australia. Last year we initially had a restricted cultivation of Roundup Ready canola in New South Wales and Victoria. Cultivation and processing of the harvest of GM canola were effectively anidentity preservation system. Farmers growing the Roundup Ready crop delivered their harvest only to specific sites that only accepted GM canola. The conventional farmers delivered their harvests to other sites. This year we have a more mixed system. Several delivery sites accepted both GM and non-GM canola, whereas others only took conventional canola. Farmers could choose to whom they sold their crops.

GMO Safety: How is it being ensured in Australia that farmers can continue to cultivate conventional canola? Pollen from fields with GM canola can uncontrollably reach neighbouring fields of conventional canola.

Christopher Preston: Co-existence is primarily a response to maket requirements. Growers have a series of requirements they have to comply with in order to grow GM canola. On buying GM canola seed, farmers have to agree to follow certain measures for cultivation. These comprise training courses for the farmers and the maintenance of a minimum distance of five meters between fields sown with GM and conventional canola. For seed production, a minimum distance must be at least 400 meters to a GM canola field. Farmers in the vicinity must be informed about the cultivation, agricultural machines have to be correctly cleaned after being used on fields under GM crops and canola volunteers emerging in fields in the season after GM canola production have to be controlled.

GMO Safety: Are there any governmental regulations for coexistence in Australia?

Christopher Preston: The only regulations that we have regarding co-existence are thresholds for GM adventitious presence in non-GM seed. These are 0.5% for seed for sowing and 0.9% for grain. Conventional canola must not contain more than this amount of GM seed. Through this measure we ensure that conventional canola complies with market requirements for import markets such as the EU. This responsibility lies with the farmers. We believe that the established management of cultivation is sufficient to maintain this threshold. If the threshold is exceeded in a conventional canola harvest, then the farmer can sell the canola as a GM crop. Thus, normally, there is no economic loss for the farmer. In Australia, higher prices for conventional canola are an exception. The price advantage of conventional canola is presently nil to at most 15 dollars a ton. In addition, in Australia, there is as virtually no organically grown canola. A few farmers have grown organic canola from time to time on small areas, but this is very uncommon. If this changes in the future, then naturally our handling of coexistence will be reconsidered.

GMO Safety: Is there a special liability law in Australia for that case that conventional canola is mixed with GM canola causing an economic damage?

Christopher Preston: As already said, coexistence here is a response to market requirements. We have a tradition here of as few statutory market regulations as possible. Regulations regarding GM crops are to protect the environment and human health. In Australia, GM canola is not considered detrimental to either health or the environment. Therefore, there are no special liability laws for the case that GM canola is found in conventional canola. Coexistence is a market tool and future directions in co-existence will be dictated by market requirements. This is greatly different to the case in the EU, where coexistence is statutorily controlled and governments decide how the market should develop.

GMO Safety: You said that the currently established coexistence measures in agriculture are sufficient to ensure that the GMO thresholds for conventional canola production can be met in nearly all cases. Have scientific investigations been carried out in Australia to show this?

Christopher Preston: Yes, the corresponding findings are available here. In Australia the canola fields are, on average, much larger than for example in Europe. Here there are fields of a hundred hectares or more. This greatly reduces the levels of undesired admixing of GM canola in conventional canola. In larger fields GMO pollen arriving from outside will be more diluted by pollen within the non-GM field. Our studies have suggested that GMO presence in a field of conventional canola due to pollen movement will not be higher than 0.5 percent, even when 80 percent of the surrounding fields have been cultivated with GM canola. Also, movement of GM pollen by bees has been investigated. This study suggested that only where canola fields are small, less than five hectares, could the amount of GMO present in the non-GM field reach 0.5 percent. Further investigations have evaluated the possible roles of volunteer canola and agricultural machinery in the unintentional spread of GM canola. Here as well the comparatively larger fields in Australia lead to a very low risk for the accidental entry of GMOs into conventional fields will result in GM presence above the threshold.

GMO Safety: Dr. Preston, thank you for this interview.