Variations in maize pollen emission and deposition in relation to microclimate

Nathalie Jarosz (1) , Benjamin Loubet (1) , Brigitte Durand (1) , Xaxier Foueillassar (2) , Laurent Huber (1)

1 EGC - Environnement et Grandes Cultures
2 ARVALIS - Institut du végétal [Paris]

The co-existence of genetically modified (GM) crops with conventional crops has become a subject of debate and inquiry. Maize (Zea mays L.) is one of the most cultivated crop plants in the world and there is a need to assess the risks of cross-pollination. Concentration and deposition rate downwind from different-sized maize crops were measured during three flowering seasons, together with micrometeorological conditions in the surrounding environ-ment. Pollen release started once the air vapour pressure deficit (VPD) increases above 0.2 to 0.5 kPa. Moreover, the dynamics of release was correlated with the dynamics of VPD sur-rounding the tassels. Horizontal deposition appeared to follow a power law over short dis-tance downwind from the source, and the dispersal distance increased with the source canopy height, and the roughness length of the downwind canopy. This work also provides a data set containing both pollen measurements and contrasting weather conditions to validate dispersal models and further investigate maize pollen dispersal processes.

Mots clés: production; dispersion; atmospheric transport; deposition velocity; field experiment

Domaines: Ecologie, Environnement

Nathalie Jarosz, Benjamin Loubet, Brigitte Durand, Xaxier Foueillassar, Laurent Huber. Variations in maize pollen emission and deposition in relation to microclimate. Environmental Science and Technology, 2005, 39, pp.4377-4384. ⟨10.1021/es0494252⟩. ⟨hal-00351096⟩