Estimation of the Heading Days Under the Effect of Light Pollution Using a Model for Predicting Developmental Process in Rice

Exterior illumination in populated areas is part of the basic infrastructure used to secure relief from darkness and to ensure safety for social and economic activity at night. However, it can also be a source of light pollution. In wet rice cultivation, light pollution due to exterior illumination results in delayed fl owering (heading), which in turn leads to a reduced yield and to a low-inspection grade at the harvest stage. Therefore, the relationship between a delayed heading period and the light intensity or irradiation period needs to be studied. This study attempts to models the rice growth process in light pollution to propose lighting and cultivation management that will ensure pedestrian safety as much as possible while utilizing countermeasures against light pollution at effective and appropriate times.