photoperiodism in plants. photoperiodism – the regulation of seasonal activity by daylength...
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Photoperiodism in plants
Photoperiodism in plants
Photoperiodism – the regulation of seasonal activity by daylength (photoperiod).
Photoperiodism in plants
Photoperiodism – the regulation of seasonal activity by daylength (photoperiod).
Long-day plants (LDP):
- Only flower when the photoperiod exceeds a certain value, known as critical day length (CDL).
Photoperiodism in plants
Photoperiodism – the regulation of seasonal activity by daylength (photoperiod).
Long-day plants (LDP):
- Only flower when the photoperiod exceeds a certain value, known as critical day length (CDL).
- Does not have to be longer than 12 hours.
Photoperiodism in plants
Photoperiodism – the regulation of seasonal activity by daylength (photoperiod).
Long-day plants (LDP):
- Only flower when the photoperiod exceeds a certain value, known as critical day length (CDL).
- Does not have to be longer than 12 hours.
- Characteristic of higher altitudes, where seasonal variation in daylength is greater.
Photoperiodism in plants
Photoperiodism – the regulation of seasonal activity by daylength (photoperiod).
Long-day plants (LDP):
- Only flower when the photoperiod exceeds a certain value, known as critical day length (CDL).
- Does not have to be longer than 12 hours.
- Characteristic of higher altitudes, where seasonal variation in daylength is greater.
- LDP’s begin to flower when the days are lengthening, in spring and early summer – if transplanted to the tropics, it may not flower because the days aren’t long enough.
Photoperiodism in plants
Photoperiodism – the regulation of seasonal activity by daylength (photoperiod).
Long-day plants (LDP):
- Only flower when the photoperiod exceeds a certain value, known as critical day length (CDL).
- Does not have to be longer than 12 hours.
- Characteristic of higher altitudes, where seasonal variation in daylength is greater.
- LDP’s begin to flower when the days are lengthening, in spring and early summer – if transplanted to the tropics, it may not flower because the days aren’t long enough.
- EG – Temperate grasses, snapdragons, radish and lettuce
Photoperiodism in plants
Short-day plants (SDP)
- Only flower when the photoperiod is less than the CDL.
Photoperiodism in plants
Short-day plants (SDP)
- Only flower when the photoperiod is less than the CDL.
- Many native tropical species are SDP’s even though the daylength may not vary more than two hours during the year.
Photoperiodism in plants
Short-day plants (SDP)
- Only flower when the photoperiod is less than the CDL.
- Many native tropical species are SDP’s even though the daylength may not vary more than two hours during the year.
- EG – Maize and sugar cane.
Photoperiodism in plants
Short-day plants (SDP)
- Only flower when the photoperiod is less than the CDL.
- Many native tropical species are SDP’s even though the daylength may not vary more than two hours during the year.
- EG – Maize and sugar cane.
Day-neutral plants
- Are not affected by photoperiod
- EG – dandelion, tomato, and garden pea.
Photoperiodism in plants
Short-day plants (SDP)
- Only flower when the photoperiod is less than the CDL.
- Many native tropical species are SDP’s even though the daylength may not vary more than two hours during the year.
- EG – Maize and sugar cane.
Day-neutral plants
- Are not affected by photoperiod
- EG – dandelion, tomato, and garden pea.
** Over-simplification. Photoperiod can be affected by plant age, temp and nutrient availability.