2. Materials and methods
2.1. Sample collection
Corn was grown on four farms located in Ingham, Menominee,
Mason, and Saginaw counties all located in Michigan in 2010 and
2011. The latitude and longitude of the research locations within
Ingham, Mason, Menominee and Saginaw counties were
42*380
08.3100N and 84*130
32.3700W; 43*570
40.3700N and
86*090
28.9200W; 45*270
01.2700N and 87*350
33.0300W and
43*070
55.6600N and 83*580
04.6500W respectively. Two hybrid pairs,
one Bt and one near-isoline relative were analyzed giving a total of
4 hybrids with the specific hybrid pairs grown at each respective
location (Table 1). The field plots were managed consistent with the
Michigan State University, Corn Hybrid Testing Program [17] and
information on the soils present at each research location is shown
in Table 2. Soil samples were taken at time of planting and soil
conditions were observed and testing was completed by the
Michigan State University soil and plant nutrient laboratory. Fertilizers
(Nitrogen, Phosphorous and Potassium) were applied in all
the four locations at different application rates (Table 3). Hybrids
were planted from mid-May to early June and harvested from midOctober
to early November depending upon location (Table 3).