In previous studies,an increase in light intensity from 2000 to 4000 lux resulted in a considerable increase in PSB growth, but further increases in light intensity exceeding 5000 lux resulted in a substantial decrease in PSB growth.
In vorige studies, 'n toename in die lig intensiteit 2000-4000 lux gelei tot 'n aansienlike toename in PSB groei, maar verdere verhogings in die lig intensiteit van meer as 5000 lux gelei tot 'n aansienlike afname in PSB groei.