Fig. 1. Diagram of sampling transect within a seed production field relative to an adventitious pollen source. Selected seed fields were adjacent to an adventitious pollen source that overlapped at least 50% of the seed field to the North, East, South, or West. Sampling transects were located on the side of the field adjacent to the adventitious pollen source. Ears were collected along the transect at 1.8 m (6 ft), 9.4 m (31 ft), 20.6 m (68 ft), 35.8 m (118 ft), and 200 m (660 ft) from the field edge nearest to the adventitious pollen source. Blocked area surrounding the seed field indicates border rows, which varied in number with distance between seed field and adventitious pollen source.