Define a short day and a long day plant using the following:
3.1 critical daylength concept.
The critical daylength concept refers to the specific duration of daylight hours required for a plant to flower or initiate specific growth processes. Based on this concept, short day and long day plants can be defined as follows:
1. Short day plant:
A short day plant (also known as a long night plant or a day-neutral plant) is one that requires a critical daylength shorter than a certain threshold for flowering or other developmental activities. For these plants, flowering is induced when the duration of daylight falls below the critical daylength. Generally, short day plants require less than 12-14 hours of daylight to bloom. They typically initiate flowering during the fall or winter when the nights are longer.
Examples of short day plants include poinsettias, chrysanthemums, and some varieties of soybeans.
2. Long day plant:
A long day plant is one that requires a critical daylength longer than a specific threshold for flowering or other developmental processes. These plants initiate flowering when the duration of daylight exceeds the critical daylength. Long day plants typically require more than 12-14 hours of daylight to bloom. They usually flower during the spring or summer when the days are longer.
Examples of long day plants include spinach, carrots, and lettuce.