Genetically Modified Organisms - Sweet Corn and Maize

About Maize

By our best estimates, somewhere between 40,000 and 50,000 hectares of maize is grown in a normal year in New Zealand. About one-third is for grain and two-thirds for silage.

The New Zealand grain production has been:
2002 - 150,000 tonnes
2003 - 165,000 tonnes
2004 - 175,000 tonnes

The projected 2005 harvest is 155,000 tonnes.

New Zealand imports about 100,000-150,000 kg of maize seed each year for sowing.

Maize for sowing can only be imported from 14 countries. Seeds imported for processing into food or animal feed must be completely milled or treated so that those seeds are not viable.

Growing and using Maize

Maize is used in a wide variety of foodstuffs, from breakfast cereals, popcorn, starch products, and baked goods. It is also an important stock-feed, either as silage, or in grain form or processed animal feeds.

Farming practice is such that farmers do not retain a quantity of last year’s crop to grow next season. Standard practice is to purchase hybrid seed from a seed merchant each season.

Maize does not grow "wild". Maize requires warm soil temperatures to grow, and would rot or be eaten by vermin in the non-growing months.

Processing techniques for maize into human food are such that the viability of the maize kernels is destroyed. The hybrids used for food are generally different than for animal feed and for silage but there are some crossovers.

Maize pollen does not spread as easily as that of other grains due to weight. Maize pollen has a short viability in the environment.

Field Events

Date Scenario
Sweet Corn 2006-07 Two consignments of sweet corn containing a very low presence of GM seed were erroneously cleared at the border. A query was raised by BNZ and re-testing was arranged by the seed supplier. Agreement was reached that the seed should not have been imported, clearances were revoked, and the unplanted seed and young plants were destroyed.
Maize 2005 The company informed MAF that their Quality Assurance tests had shown the presence of GM Maize. MAF commissioned testing to determine the level of presence and the construct(s) involved,and discovered that the GM presence was due to contamination from GM soy flour which had previously been stored in the same holding area.
Maize 2004 BGS "Operation Cracked Kernel". Audit of a testing laboritory in the USA indicated some potential issues with the way results were reported, and re-testing was undertaken for seed consignments imported the previous season. Re-testing found some seed positive for an FSANZ approved construct. The grain produced over the 2003-04 growing season was harvested, dried, stored and devitalised under supervision.
Sweet Corn 2003 "Operation Sunshine" A GM presence was discovered in sweet corn product exported to Japan from New Zealand. The presence was detected during a routine test undertaken as part of an industry-based QA programme.
Maize 2002 "Operation Pacific". The company informed MAF that their Quality Assurance tests had shown the presence of genetically modified (GM) maize seeds in crops harvested in Gisborne and Pukekohe earlier in the year.
Maize 2001 Infamously dubbed "Corngate". Product harvested and tested positive as part of normal Quality Control programme.

Border Events

Maize 2006

Two consignments of Zea mays seeds entered New Zealand during October and November 2006 with accompanying genetic modification (GM) testing certificates which indicated conflicting test results. The GM gene construct was confirmed as *Round Up Ready* corn. All crops have now been mechanically destroyed (by power harrowing) and some have also been treated with herbicide to ensure 100% crop destruction.

Maize 2005

Maize 2004

Sweet Corn 2003

Maize 2002

Appendices

Maize 2000

Page last updated: 18 June 2008