Gisborne sweet corn investigation – Q&As
Gisborne sweet corn investigation – Questions and Answers
Thursday 7 August 2003
1. How can we be sure that the fields in Gisborne and others throughout the country won’t produce more GM corn?
For more corn to grow there has to be viable corn seeds or corn vegetation which can sprout into new plants. No evidence of corn seed or volunteer plant growth was seen either within the fields or within 3 metres around the perimeter of the fields.
Each of the four fields in Gisborne had visual inspections conducted by MAF. These inspections consisted of systematic walking ‘sweeps’ of the fields using four-person teams, which entirely covered each field. Inspectors were looking for evidence of corn seed, remaining corn vegetation (stubble) or growth of volunteer corn plants. The field teams reported a high level of confidence that nothing was missed, due to good visibility of the ground.
In addition, a leading New Zealand scientist at Crop and Food Research, specialising in maize and sweet corn breeding and growing, has provided MAF with recommendations that specifically relate to the control of volunteers in sweet corn fields. Based on this advice MAF considers that the four fields have been subjected to post-harvest cultivation treatments that would prevent any viable material remaining in the fields. Harvesting also occurs when the kernels are physiologically immature and therefore non-viable.
The other fields throughout New Zealand will be managed by a site management plan that will address a range of potential scenarios and risk. The initial indications are that many sweet corn fields are subjected to post-harvest treatments that result in a low risk of volunteer corn growing. Those post harvest treatments include measures such as immediate cultivation after harvesting so that fresh plant material is broken up and exposed to decay. Risk levels are therefore very low as any residual seed heads that might be present will be immature and because of mulching will not have the opportunity to develop further.
2. What happened to the corn that was harvested from other fields throughout New Zealand?
It is most likely that product grown in these fields has been sold and consumed. If the product had contained a presence of Bt11 sweetcorn, based on the extensive testing done on other products, it is considered highly probable that any level of presence would have been well below the 1 percent threshold for unintended presence allowed for in the Australia/New Zealand Joint Food Standards Code.
Food Standards Australia New Zealand (FSANZ ), which administers the Joint Food Standards Code assesses the safety of all GM foods before they are approved for sale. FSANZ concluded in its safety assessment that food derived from Bt11 corn was safe for human consumption.
The New Zealand Food Safety Authority therefore considers no further action is necessary in relation to product grown from these fields.
3. Where were the other fields located throughout New Zealand?
There were 16 fields in Gisborne, 74 fields in Marlborough and four fields in Canterbury.
4. What is the situation with further imports of seed from this company?
MAF, in consultation with other government departments, is reviewing the adequacy of the testing protocols used for imported sweet corn, maize, oilseed rape and soya bean seeds imported for sowing. Ministers will shortly be briefed on the conclusions reached.
5. Is there a tolerance or allowance for low levels of GM to be imported into New Zealand?
No. The law does not permit unauthorised GM seeds to be knowingly imported or planted. If GM seeds are detected, the consignment will not be allowed into New Zealand. However, there is always a chance that low concentrations of GM seeds may not be detected. The limit of reliable detection is about 0.1 percent (one seed in a thousand). This is not a barrier between what is detectable and what is not, but it indicates the level where we can confidently find GM seeds. Lower concentrations of GM seeds may be detected, but with much less confidence.
6. How are imports of seed tested?
The New Zealand testing regime is one of the strictest in the world. MAF tests imported seed for growing in the environment at the border and if there is any indication of unauthorised GM content it is not allowed in. MAF requires all consignments of sweet corn, maize, oilseed rape and soya bean seeds imported for sowing to be tested for the presence of GM material
Last year the sample sizes for testing for inadvertent GM content were increased from 1,400 to 3,200 seeds. This means that the current testing process will detect the presence of 1 GM seed in 1000 with 95 percent confidence.
7. So why wasn’t the GM picked up in the import testing process?
Unless every single seed is tested (thereby destroying it), MAF cannot guarantee 100 percent GM-free seed.
8. Why not stop all seeds from countries that produce GM varieties?
Banning imports of maize seeds would have serious negative effects in several agricultural industries, including dairying where green-feed and maize silage are widely used, but could still not provide a 100 percent guarantee to stop all GM seeds.
Imported seeds are important for many New Zealand agricultural industries – the price and quality of seeds affects the competitiveness of these industries. For example, maize is grown for food and is also an important stock feed in the dairy, pig and poultry industries. Many of the best quality seeds come from countries that grow GM crops, which are the world’s major seed producers. Banning seeds from those countries would limit access to those seeds and would probably raise the price of seeds, which would negatively affect those industries that rely on imported seeds.
Although the costs of a ban are not clear, the value of these crops gives an indication of their importance. MAF estimates that the annual gross value of maize is about $70 million and that it adds $60 million in extra production to the dairy industry. The annual gross margin of the canola/oilseed rape crop is about $1.8 million. New Zealand also has a seed multiplication industry worth about $20-$30 million. This issue highlights that as a trading nation, New Zealand faces both risks and benefits from trade. In this case, the benefits of importing seeds outweigh the risks.
9. Are GM plants already growing in New Zealand?
Testing at the border is rigorous and, when inadvertent GM content is found, MAF acts immediately to control the situation. With more and more GM crops being grown and traded around the world, there will be more opportunities for inadvertent presence in seed supplies. On the other hand, the systems to separate GM and non-GM crops are likely to improve, driven both by commercial pressures and demands from governments for assurances.
It is probably inevitable that there will be some instances of GM seeds being inadvertently imported, but with appropriate actions and ongoing assurance systems, it should be possible to keep them isolated. There is always a chance that some low levels of GM seeds may not be detected, but most of the time it will be detected by the assurance systems that are in place.
MAF will investigate the suspected presence of any GM seeds as it would for any other case where there is evidence of a breach of the Biosecurity Act 1993.
10. Is there any connection between this event and Pacific Seeds?
No. The two cases involve different GMOs and are kilometres apart.
11. If we got another call from Japan would we go through this exercise again?
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