Table 18 continued.
Source DF SS MS F Prob F
Regression 2 343.94 171.97 29.81 0.001
Error 284 1638.59 5.77
Corrected Total 286 1982.53
Source DF Partial SS F Prob F
Agasicles 1 288.82 50.06 0.0001
Vogtia 1 108.97 18.82 0.0001
In table 19 the overall effect of each of the independent
variables on the plant characteristics as a whole is shown.
Like the previous programs, F values were calculated using
all independent variables in the first model and secondly
with only the insect variables included. Pillai's Trace
with the F statistic was used as a test for significance.
When all variables were included only one independent
variable lacked significance, chlorides. Variables with
larger F values and therefore more important sources of
variation were: Iron, turbidity, nitrates, hardness, water
depth, and Agasicles. With only the insect variables
included, both Agasicles and Vogtia were significant at
greater than the .01 probability level.