Table 2. Summary of repeated measures ANOVA to test the effects of petroleum pollution, plant growth stage and their interaction (petroleum × stage) on protease, L-asparaginase and AMF colonization.

Parameters	Source of variation	Degrees of freedom (df1, df2)	F value	Significance
Protease	Petroleum	6,21	2.79	<0.05
	Stage	2, 20	61.43	<0.0001
	Petroleum × stage	12, 42	1.60	NS
L-Asparaginase	Petroleum	6, 21	5.34	<0.01
	Stage	2, 20	173.99	<0.0001
	Petroleum × stage	12, 42	3.07	<0.01
AMF colonization	Petroleum	6, 21	2.28	NS
	Stage	2, 20	6.67	<0.01
	Petroleum × stage	12, 42	2.20	<0.05