Release of `CO_(2)` and intake of `O_(2)` suggests that either photosynthesis is not taking place or its rate is too low.
Normally during the day , `CO_(2)` generated during respiration is used up in photosynthesis , hence, there is no `CO_(2)` liberates into the atmosphere . i.e., rate of photosynthesis is much more than the rate of respiration . Instead , oxygen release is major event at this time.