1. The tendency of SPAD was T2>T1>CK≥T3 overall, the SPAD of Stevia rebaudiana Bertoni in T2
was 6.28% higher than that in CK, and it was 2.81% higher in T2 than that in CK, those were both
significant, but the diversity of the SPAD of chlorophyll between T1 and T2 were not significant, and
there was no significant difference between T 3 and CK.