Appendix C. The effects of aphid density, ants, and plant genotype on the final number of aphids per plant.
TABLE C1. The effects of initial aphid density, the presence/absence of ants, and plant genotype on the final number of aphids per plant. Spatial block and the person who counted aphids on a plant (counter) were included as blocking factors. I calculated the percent variation (% Var) explained by all main effects and significant interactions using general linear models using the equation: (factor-sums of squares)/(total sums of squares) × 100%. The variance components (VC) for all random effects are also provided. Significant effects (P < 0.05) are in bold.
Source |
VC |
F/ |
P |
% Var |
Initial density (density)† |
76.52 |
<0.001 |
6 |
|
Ants† |
9.14 |
0.003 |
0.8 |
|
Genotype |
0.84 |
31.3 |
<0.001 |
27.1 |
Block |
0.1 |
22.1 |
<0.001 |
2.3 |
Counter† |
1.12 |
0.33 |
0.6 |
|
Density × Ants† |
5.47 |
0.02 |
0.5 |
|
Density × genotype |
<0.01 |
0 |
- |
- |
Ants × genotype |
0.03 |
0.5 |
0.24 |
- |
Ants × counter† |
3.55 |
0.03 |
0.2 |
|
Density × ants × counter† |
2.18 |
0.07 |
- |
|
Residual |
1.99 |
|||
† Denotes fixed effect in which the
significance was assessed using an F statistic. All other effects in the model were
random and their significance was tested using a
-statistic
from log-likelihood ratio tests.