GMO cross-fertilization by airborne pollen found at surprisingly large distances

Genetically modified organisms (GMO) pollution caused by pollen drift is spreading in GM crops cultivation areas such as the USA and in Canada. GMO contamination will occur once GM crops are cultivated. Therefore, the co-existence between GMO farming and conventional farming or organic farming is very difficult. This fact was proven by a research study conducted in Hokkaido, Japan.

The national guidelines for GM crop cultivation in Japan by the Ministry of Agriculture, Forestry and Fisheries of Japan (MAFF) has set the buffer zones for outdoor cultivation for research purposes. However the distances for buffer zones are set extremely short, thus there is no way to prevent GMO pollution under such circumstances.

According to Hokkaido's Ordinance for Prevention of Cross-fertilization Cultivation of GM Crops, which was enforced in January 2006, commercial planting of GM crops is banned in principle, trial cultivation is allowed upon notification, in which case isolation buffer zones from conventional crops on ordinary farmland are stipulated. The isolation buffer zone distances stipulated under the Ordinance are quite severe, being at least twice those mentioned under MAFF guidelines. For rice, for example, the MAFF guideline buffer zone distance is 30 m, but under Hokkaido’s Ordinance it is 300 m.

Hokkaido has carried out cross-fertilization trials for three years from 2006 to 2008 in order to test whether the isolation buffer zone distances stipulated in the Ordinance were meaningful or not. The results announced on 13 February 2008 were the results for the trials in 2007.

The five crops covered by the trials were rice, soybean, maize, rapeseed and sugar beet. With regard to rapeseed, only the kinds of insects that visited the flowers and the preventive effect of insect nets were investigated. For soybeans, a similar investigation as that for rapeseed was carried out in addition to the cross-fertilization trial. In the cross-fertilization trials, pollen collecting pots were placed at various distances downwind, each grain being analysed after collection.

In the case of rice, since cross-fertilization had occurred during the 2006 trial at the maximum distance stipulated in the Ordinance, 300 m, the trial was carried out using the distances of 450 m and 600 m in 2007. The result was that cross-fertilization occurred even at the 600 m distance. Cross-fertilization was also found to occur for maize at the maximum distance of 1200 m, and at 990 m for sugar beet.

As can be seen from the case of rice, it has been confirmed that airborne diffusion of pollen occurs over surprisingly large distances. The view that the current buffer zone distances are insufficient to prevent the occurrence of cross-fertilization is now becoming widespread. At the same time, the unrealistic nature of the MAFF guidelines has been thrown into sharp focus.

From this data we have to conclude that buffer zones can not prevent GMO cross-contamination.