Fig 1.

Spores per gram of dry soil in soil samples collected from each Bt and P plot in May 2009 (initial) and October 2009 (final). Five initial soil samples were collected from each plot and pooled for the spore extraction to determine initial spore abundance and diversity per plot before seeding. Spores were categorized into five morphological groups (medium brown [mbrn], large brown [lgbrn], large black [lgblk], small brown [smbrn], and red), and total spores per gram dry soil were calculated. Five final soil samples were collected from each plot at the end of the field season, and spores were extracted from five soil samples per plot to determine whether Bt maize had a negative effect on spore abundance and diversity after one growing season. Open bars represent the means (± SE) of spore counts from initial soil samples collected from P plots, and solid bars represent the means (± SE) of initial spore counts from Bt plots; bars with hatched lines represent final spore counts collected from P plots (light gray lines) and Bt plots (dark gray lines). n = 10 for P initial; n = 14 for Bt initial; n = 50 for P final; n = 70 for Bt final.