Jul 11, 2006

Coexistence

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BMELV coexistence research programme 2006

Locations, experimental design, research questions

How large should the separation distances be between fields with genetically modified and conventional maize in order to ensure that there is a high probability of GMO traces in the conventional maize remaining below the 0.9 per cent threshold? This is the question being investigated by the research programme on ensuring coexistence started by the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) in 2005. The modified trial programme is being continued in 2006.

Size and location of the trial fields: The trials are taking place at six locations (Braunschweig, Wendhausen, Groß-Lüsewitz, Mariensee, Forchheim and Dahnsdorf). The total size of the trial fields is 75 hectares. At some locations there are several trials.

Research aim: The aim of the research is to ensure the coexistence of non-GM and GM agriculture. The primary objective is to collect scientifically confirmed data on maize pollen dispersal and incrossing levels.

Experiment design: The trials are arranged according to a standard pattern. There are two basic designs, so that the results from the different locations can be compared.

Test systems: Bt maize is being used as a pollen source (donor) at five sites. The project is studying the amount of pollen that enters an isogenic variety (recipient). At three trial sites incrossing rates are being recorded on a (genetically unmodified) variety of white maize. However, this test system does not provide exact measurements – just qualitative indications for comparative experiments.

Research questions: The data is to be used as a basis for making recommendations for minimum distances between GM maize and conventional maize fields. The BMELV has announced that it will be issuing rules of good farming practice in which a minimum distance will be prescribed.

The project is also investigating what effect the crop species planted between the maize fields has on the incrossing rate. In 2005 a clover/grass mix (short and moist) was compared with tall sunflowers. It was found that sunflowers do not act as a physical barrier to pollen drift. In 2006 the project is comparing areas of clover/grass mix with cereal stubble.

This year the project is also investigating the effectiveness of a cordon of conventional maize planted between the Bt maize field and the adjoining conventional crop. In farming practice the cordon would be harvested together with the GM maize and used in the same way.

The project is also investigating the impact of the drill direction in the conventional maize crop. If the rows of maize are at right angles to the wind direction and pollen drift, the first rows could act as a barrier. If the maize rows are planted parallel to the wind direction, the pollen could be expected to be carried further into the crop. The impact of the drill direction is being investigated at two locations.

Wind dependence: All the trial fields aimed at researching distance-related incrossing rates are placed in the direction of the prevailing wind. There is a prevailing westerly wind at all the sites. The plots with conventional maize are therefore positioned to the east of the Bt maize plot. This simulates the worst case scenario for pollen drift and incrossing.

There is a weather station at all the sites. Here the wind direction, wind speed, temperature, air humidity, precipitation and sunshine are measured during the flowering period.

Sampling: Generally, maize cobs are taken as samples, although chopped whole plants are also used on some sites. This is designed to enable a comparison between silo and grain maize. All samples from the Bt maize trial fields are examined by an external laboratory.