Table 4: Results from quadratic least squares regression when evaluating the effect of soil pH on grain sorghum relative yield (2009 and 2010).

DFMean square Prob

2009
Lahoma20.062.310.1330.24
Perkins20.040.350.70820.04
All locations20.183.230.05420.18

2010
Lahoma20.061.590.23710.17
Perkins21.2437.67<0.00010.83
Haskell20.2515.650.00020.68
All locations21.1222.82<0.00010.47