highly significantp = 0
The same LED treatments showed a highly significant ( p = 0) difference in lettuce antioxidant activity (in μmol FeSO 4 L −1 ) when the intensity of lights became lower 60 μmol m −2 s −1 ( Figure 3 B), and the highest level of antioxidant activity (in μmol FeSO 4 L −1 ) was at B345/R, followed by B450/R, with increasing rate by about 53 and 420%, compared with B450/R and B/R-rich, respectively.