| The duration of light is probably not as important to plants as the quality of the wave lengths. Some street lamps affect plant growth much more adversely than others. The attached link describes some of the problems associated with some street lights. Photoperiodic response in plants varies from species to species. They will fall under one of three categories: short-day, long-day, and day-neutral. Those that are short-day plants respond to nights longer than about 12 hours (thus, short day). Those plants will be induced to flower under those conditions. Long-day plants are triggered to flower when the nights are shorter than around 12 hours. Day-neutral plants don't respond to the number of hours of darkness, but will bloom according to other requirements. You can look up any plant on the internet to find out its photoperiodic category. And hybrids can certainly be long day plants. Or short day or neutral. |
Here is a link that might be useful: Effects of street lighting
