Figure 2

Analyzed cross-pollination studies. Literature studies on distance-related out-crossing rates in hybrid maize fields (a) used for the development of the dispersal kernel (b), projected on a double logarithmic scale. The data shows a regression function with a gradual reduction in hybridization rates from 0.14% at 100 m, 0.1% at 200 m, and 0.06% at 250 m and about 0.01% at over 1,000 m. The displayed references in (a) are quoted in the reference list. The data of Ortega Molina (2003a) and (2003b) were republished in 2004.