Fig. 2. Ratio of root intersections of common bean plants in the top 5 cm of the soil to the total number of root intersections as affected by genotype, competition and phosphorus availability in the field in China. Two pairs of RILs, 17 and 24 (a) and 7 and 38 (b), are compared. Each bar represents the mean of five replicates; error bar represents the standard error of the mean. In the competition treatments roots of competing plants were analyzed as a group because they could not be separated.