Field layout for Bainsvlei 2005/2006 and 2006/2007 and Waterbron 2006/2007. Field layout drawn to scale for Bainsvlei 2005/2006 and 2006/2007 (180 × 230 m) and Waterbron 2006/2007 (180 × 800 m). The open centre block represents the donor yellow GM maize and the surrounding grey block the recipient white non-GM maize. Cobs were collected along the 16 transects every 2 m up to 100 m and a further 200 m at 10 m intervals at Waterbron as indicated by the dashed line. Pollen traps (indicated by X within the non-GM maize field) were set at 50 m intervals in four directions and continued up to 400 m.