What tool is used to control chrysanthemum blooming?

• A. Greenhouse thermostat
• B. Photoperiodic control
• C. Hydroponic nutrient mix
• D. Pesticide scheduling

Answer: (B)

Photoperiodic control is what triggers flowering in chrysanthemums. These plants respond to the length of day and night, so by adjusting light exposure in the greenhouse you can signal the buds to form and time flowering to a specific date. Forcing bloom usually means extending uninterrupted darkness with blackout curtains (or, for some crops, carefully adding or removing light to achieve the right night length). Temperature or nutrients matter for overall growth and bloom quality, but they don’t provide the specific timing cue that the plant uses to decide when to flower. Pesticide scheduling has no direct effect on flowering time.