Improved method for nondestructive measurement of dynamic pollen source strength from transgenic crops using sonic anemometer

Pollen-mediated gene flow from transgenic crops is a concern of the scientific community as well as the general public. Current lack is a nondestructive method to measure dynamic (hourly or shorter time period) source pollen release rate (source strength) from these crops. This paper reports an improved method using Rotorod concentration samplers and sticky slides, together with a fast response sonic anemometer, for measuring source strength from transgenic corn crops. Field measurements were made during the pollination season of 2001 at the Agronomy Research Farm, University of Connecticut, Storrs, Connecticut. Data were analyzed and used to estimate the pollen source strength of the corn crops at hourly time steps by considering both atmospheric transport and gravitational deposition processes. Details of the calculation and assumptions of the method are provided. Results from this study demonstrate that this method is sufficiently robust for use in estimating pollen source strength of transgenic crops with heavy pollen grains in assessing gene flow risks associated with field production of transgenic crops.