1. Plural of photoperiodism; the physiological responses of organisms to the length of day and night, particularly the duration of light exposure.
Usage: technical; biology; usually used in plural or as a mass noun

Examples

• Plants exhibit various photoperiodisms that determine when they flower based on seasonal light changes.
• The study of photoperiodisms in migratory birds reveals how day length triggers breeding and migration cycles.
• Researchers investigate photoperiodisms to understand how organisms adapt to changing seasons.
• Photoperiodisms in insects control diapause, a dormant state triggered by shortening days.
• Agricultural scientists manipulate photoperiodisms in greenhouses to control crop flowering times.