How to distinguish GM crops from space

NASA satellite technology could soon be used to help food producers distinguish between GM (genetically modified) crops and non-GM crops, opening the door to greater acceptance of GM food, writes Anthony Fletcher.

The sale of GM foods has put nations at loggerheads with each other. The EU and Japan have enacted labelling and traceability requirements for GM food products, while the US and Canada believe the technology is safe and that such standards are not necessary.

To date, the consumption of GM foods has not caused any known negative health effects and current evaluations of GM primarily focus on the ecological and agricultural ramifications such as gene drift and the accidental cross-pollination of GM and non-GM crops.

Indeed, a major fear of anti-GM countries is that non-GM crops could easily be contaminated with GM pollen. If scientists could find a way of guaranteeing the 'purity' of non-GM crops, this could lead to greater acceptance of GM products as a category of food that consumers have an active choice over whether they consume or not.

This is why hyperspectral imaging has such potential. It could be used to provide data on a crop's health status, need for irrigation, pest attacks, weed status, soil nutrient and other previously unquantifiable variables, including gene drift.

Hypersptectral imaging uses a special camera to cut one photograph into 120 color-specific images. Each image shows a unique characteristic, not visible to the human eye. The US Environmental Protection Agency (EPA) is now working with NASA to adapt hyperspectral imaging for agricultural use.

The technology could also enable the sector to prevent corn pests from developing resistance. Pest resistance could severely limit the continued use of some new varieties of corn. The technology could monitor crops and warn producers of developing pest resistance.

In 2004 about 81m hectares of land was being used to grow GM crops by seven million farmers in 18 countries, mainly the US, Argentina, Canada, Brazil, China, Paraguay and South Africa.

The first major GM food was introduced on the market in the mid-1990s and paved the way for the growing of strains of maize, soybeans, rapeseed and cotton. GM varieties of papaya, potato, rice, squash, sugar beet and tomato have been released in certain countries. WHO estimates that at the end of 2004 GM crops covered about four per cent of the total global arable land.

Hyperspectral imaging is part of the growing arsenal of precision farming technologies. These technologies include geographic information systems (GIS), automated machine guidance, infield and remote sensing, mobile computing, telecommunications and advanced information processing.

The global positioning system (GPS) is another key technology used in precision farming that provides highly accurate geo-spatial information.

The hyperspectral camera and its applications were developed by the Institute for Technology Development at NASA's Stennis Space Center in Mississippi.