Day neutral plants are plants whose flowering is not controlled by photoperiod. They flower whatever the lengths of the day and night.Instead, flowering in day neutral plants is triggered by internal factors, such as the plant reaching a certain age or size (for example a certain number of leaves), or by other environmental factors such as temperature or water availability. Examples include tomatoes, cucumbers and some varieties of strawberry.Phytochrome is still present in day neutral plants and still controls other responses, such as seed germination and shade avoidance, but the amount of Pfr does not decide when they flower.Comparing the three groups- Long day plants: flower when the night is shorter than a critical length; Pfr promotes flowering.
- Short day plants: flower when the night is longer than a critical length; Pfr inhibits flowering.
- Day neutral plants: flowering does not depend on night length.AdvantagesDay length is not always a useful signal. Near the equator, day and night are both about 12 hours long all year round, so photoperiod gives a plant little information about the season. Day neutral plants can also flower several times, or continuously, through a long growing season.For farmers and gardeners, day neutral varieties are useful because they can be grown and harvested at many different latitudes and times of year. Day neutral strawberries, for example, can produce fruit from early summer until autumn, and tomatoes grown in heated glasshouses can fruit for most of the year.
- Short day plants: flower when the night is longer than a critical length; Pfr inhibits flowering.
- Day neutral plants: flowering does not depend on night length.AdvantagesDay length is not always a useful signal. Near the equator, day and night are both about 12 hours long all year round, so photoperiod gives a plant little information about the season. Day neutral plants can also flower several times, or continuously, through a long growing season.For farmers and gardeners, day neutral varieties are useful because they can be grown and harvested at many different latitudes and times of year. Day neutral strawberries, for example, can produce fruit from early summer until autumn, and tomatoes grown in heated glasshouses can fruit for most of the year.