A plant scientist was hired by a greenhouse operator to devise a way to force iris plants to bloom in the short days of winter. Iris normally blooms as a long-day (short-night) plant. Which of the following treatments has the best chance of creating iris blooms in winter?
A) artificially increase the period of darkness in the greenhouse
B) increase the temperature to more closely follow summer temperatures
C) alternate 4 hours of darkness with 4 hours of light repeatedly over each 24-hour period
D) interrupt the long winter nights with a brief period of light

Question

Quizplus · Accepted Answer

Iris plants are long-day plants, meaning they require shorter nights to trigger blooming. Interrupting the long winter nights with a brief period of light effectively simulates shorter nights, encouraging the plants to bloom.

A Plant Scientist Was Hired by a Greenhouse Operator to Devise