Table 1.

Results of statistical tests examining the effects of CO₂, temperature (Temp), aphid presence and Si supplementation (Si) on plant growth, root nodulation, and foliar Si concentrations.

Plant response Model fixed effect	Dry mass1		Root nodules		Si concentration1
	F1,304	P	RD1,304	P	F1,94	P
CO2	51.86	<0.001	409.15	<0.001	1.32	0.25
Temp	10.28	<0.001	384.58	<0.001	0.37	0.54
Aphids	7.36	0.01	384.57	0.90	1.17	0.28
Si	150.55	<0.001	352.27	<0.001	15.22	<0.001
CO2 × Temp	3.19	0.07	351.81	0.50	2.09	0.15
CO2 × Aphids	0.11	0.74	349.06	0.10	0.01	0.99
Temp × Aphids	0.63	0.43	345.60	0.06	1.03	0.31
CO2 × Si	4.06	0.04	344.47	0.29	0.07	0.80
Temp × Si	2.00	0.16	336.69	0.01	0.01	0.92
Aphids × Si	1.83	0.18	336.66	0.86	0.15	0.70
CO2 × Temp × Aphids	1.07	0.30	335.82	0.36	0.42	0.52
CO2 × Temp × Si	8.70	<0.001	334.95	0.35	0.43	0.51
CO2 × Aphids × Si	0.26	0.61	333.17	0.18	0.51	0.48
Temp × Aphids × Si	0.25	0.61	332.97	0.65	0.06	0.81
CO2 × Temp × Aphids × Si	0.06	0.81	332.95	0.90	0.84	0.36

Statistically significant (P < 0.05) factors indicated in bold with Fisher’s (F) or residual deviation (RD) given depending on the models used. Analysis conducted on transformed data as indicated.

¹Log transformed. Degrees of freedom in each column apply to all effects.