Pollen is designed to travel. The fact that pollen from GM plants is no exception has been a major source of controversy in the public debate on co-existence. Co-Extra is one of several projects looking into exactly what factors influence the movement of pollen. A better understanding of pollen flow will help to give farmers a better idea of conditions which are conducive to out-crossing - and how, thereby, to avoid it.
Top priority: Maize pollen
Flowering maize plants release pollen into the air, which can travel distances between a few centimetres and several kilometres.Maize is the only transgenic crop commercially grown in the European Union at this time. It is also the only major field crop that is primarily wind pollinated, which means that maize pollen movement is greatly affected by complex factors such as microclimate and local geography. To make the movement of maize pollen more predictable, many field trials have already been conducted at both the national and EU level. One of the first tasks of Co-Extra is to compile existing knowledge of maize pollen movement from previous studies.
As an addition to existing research, Co-Extra is initiating several projects to find out more about how maize pollen travels. Because wind and air currents can be modified by trees, crops, and other landscape features, research is being done to understand the effect of types of land use on long-distance pollen movement.
To understand when and where pollen travels, it is first important to know under what conditions pollen is released. Pollen emission depends on several factors including the variety of maize, the condition of the plant, and weather conditions. When conditions are wet, for instance, pollen release will be delayed. When conditions are overly dry, pollen may be on the move but may dry out, and die, before it reaches distant maize plants. After pinpointing how each of these factors affect pollen emission, Co-Extra researchers will use sophisticated computer modelling to predict pollen release and movement on a landscape scale. This project is partly based on approaches initiated by the EU project SIGMEA.
These studies will be conducted in diverse regions throughout Europe, each with different climatic conditions and agricultural landscapes. The results of these studies will enable practical solutions for managing pollen flow to be developed, which would be a further step toward co-existence on the farm.