| Calhoun measured responses to varying photoperiods, but tested only one animal in non-normal photoperiods. |
| By rounding the hours, and then calculating morning and afternoon photoperiods, the students can easily calculate the entire day's photoperiod. |
| Researchers collected early and late season eggs, separating some into component parts and incubating others for short or long photoperiods. |
| The photoperiods were lengthened by high-pressure sodium lamps or shortened by black screens when necessary. |
| We can grow these strawberries under shorter photoperiods than we thought and still get pretty much the same amount of yield. |
| Growth, gonadal development and spawning time of Atlantic cod reared under different photoperiods. |
