For example, evidence from previous work can be used as a basis for generalised estimates of percentages of pollen concentrations remaining airborne downwind in low to moderate wind speeds compared with concentrations at 1m from the source. The implications of these figures for potential cross pollination are considered but it is emphasised. that they should be used as rough guidelines only. In addition it should be noted that dispersal gradients would be altered by factors such as climatic conditions and local topography. Transport on the airflow over longer distances is likely to occur under a range of weather situations including uplift and horizontal movement in convection cells, and uplift and transport in frontal storms. Dispersal away from the vicinity of the crop also takes place by carriage on bees.
Evidence is cited that maize pollen is collected by bees in notable amounts.
In this way the pollen is transported several miles from the crop plot in suitable weather conditions. In any assessment of pollen flow from maize plots consideration should be given to the limitations of evidence from empirical studies and from results based on theoretical models. Acknowledgement must be given to the potential movement of maize pollen by bees and the possibilities of long range transport under certain weather conditions. In accordance with Title 17 U.S.C. Section 107, this material is distributed for research and educational purposes only.