The PPO activity of plants was higher in treatments CKn + CKp
and CKn + BIOIIp than those in the nursery-only application of BIOs.
A lower PPO activity was also observed in treatments BIOIn + BIOIIp
and BIOIIn + CKp, equivalent to 49% and 62% decreases as compared
to that of control, respectively. Plants treated with organic fertilizer only showed no significant difference as compared to control
(Fig. 5A).