my nellie
Masterpiece
Some days ago I posted a question of mine regarding plants' need for darkness in previously existing threads about artificial lighting.
In the meantime I did a search on the internet and I kept the main points of those scientific articles, papers etc.
I think I would like to share what I have come across my search for anyone who might be interested in this matter.
I would also like to ask anyone who is qualified by profession and studies to comment on.
Certainly you will find it lengthy but this is the most compressed summary I could make..., so thank you for your time!
Plants and animals are programmed to function in a certain pattern of daylight and darkness. Alter those patterns and unhealthy things often happen.
Plants have a diurnal cycle just like animals. They need darkness to reset the biochemical mechanisms and rebuilt the enzymes needed for the Krebs cycle.
There must be a distinct and indisputable difference between daylight and nighttime hours in indoor growing plants, just as there would be if they were growing outdoors.
Plants are naturally programmed to perform certain functions in the dark that are not possible when a source of light is present. Without this, plants cannot properly breathe or process their food, not being able to convert the day’s stored up energy into sugars they can consume or to get oxygen and release CO2. This is known as respiration, the lack of which leads to lesser root growth and an overall slowing even failure of crop development.
During daylight hours plants are busy creating carbohydrates from the energy the sun bestows which is technically known as photosynthesis. They are also taking in carbon dioxide and putting out oxygen.
When the sun goes down, plants shut down too. They fold their leaves, close their flowers and stomata, a phenomenon that to a human suggests they are sleeping. But not quite, they have much to accomplish before sunrise.
A new study sheds light and shows that plants actually get ready to respond to light (by growing, flowering or straining toward the light) while it’s still dark.
Researchers studied Arabidopsis, a small flowering plant commonly used in experiments, to tease apart the molecular mechanism the plant uses to respond to light. They found that while it is still dark, the plant produces and stockpiles a pair of closely related proteins (known as FHY3 and FAR1) that in turn increase production of another pair of proteins (known as FHY1 and FHL), key components of the light response mechanism.
The ability of plants and animals to measure environmental day length (photoperiod), typically by monitoring night length is called photoperiodism.
Photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light and dark periods.
The biological ability to measure photoperiod permits organisms to ascertain the time of year and develop seasonally appropriate physiological and behavioral adaptations.
It has been known since the 1940s that it is the duration of uninterrupted darkness during a 24 hour cycle that governs developmental processes in trees such as dormancy, shoot growth, and flowering.
Photoperiod controls spring and autumn phenology of trees, and also regulates developmental processes such as vegetative development and flowering.
Plants measure day length from the amount of blue and red light absorbed during the day; thus, plants integrate photoperiod and light quality in order to determine the day length.
Trees as well as other plants are classified as short-day, long-day, or day-neutral according to their response to day length.
Short-day trees flower and enter dormancy when day length shortens in late summer.
Long-day trees flower in early summer and continue vegetative growth until days shorten in the fall.
Day-neutral trees are not affected by day length at all.
Photoperiod can also influence leaf shape; surface hairiness (pubescence); pigment formation; autumn drop time; and root development, as well as onset and breaking of bud dormancy. Some types of night lighting can alter the natural photoperiod and, consequently, upset these developmental processes.
Artificial lighting, especially from a source that emits in the red to infrared range of the spectrum, extends the day length and can change flowering patterns, and most importantly, promote continued growth thereby preventing trees from developing dormancy that allows them to survive the rigors of winter weather.
Although we classify plants as short-day or long-day, in some cases, plants may actually be measuring the length of the night. That is, it can be the length of the period of continuous darkness, not the length of the period of continuous light, that determines whether or not the plant flowers.
Typical short-day plants share the following characteristics:
The study of this biological need for darkness is called scotobiology.
In discussing scotobiology, it is important to remember that darkness (the absence of light) is seldom absolute.
An important aspect of any scotobiological phenomenon is the level and quality (wavelength) of light that is below the threshold of detection for that phenomenon and in any specific organism.
There are substantial levels of natural light pollution at night, of which moonlight is usually the strongest. For example, plants that rely on night length to program their behaviour have the capacity to ignore full moonlight during an otherwise dark night.
Study the plant you are growing and find out what climates it does best in, and try to simulate or optimize those light cycles.
Plants only set bloom when the night length is just right. Overworked plants obviously won’t be efficient at all, and declining health invites pests and disease to wreak havoc.
In the meantime I did a search on the internet and I kept the main points of those scientific articles, papers etc.
I think I would like to share what I have come across my search for anyone who might be interested in this matter.
I would also like to ask anyone who is qualified by profession and studies to comment on.
Certainly you will find it lengthy but this is the most compressed summary I could make..., so thank you for your time!
Plants and animals are programmed to function in a certain pattern of daylight and darkness. Alter those patterns and unhealthy things often happen.
Plants have a diurnal cycle just like animals. They need darkness to reset the biochemical mechanisms and rebuilt the enzymes needed for the Krebs cycle.
There must be a distinct and indisputable difference between daylight and nighttime hours in indoor growing plants, just as there would be if they were growing outdoors.
Plants are naturally programmed to perform certain functions in the dark that are not possible when a source of light is present. Without this, plants cannot properly breathe or process their food, not being able to convert the day’s stored up energy into sugars they can consume or to get oxygen and release CO2. This is known as respiration, the lack of which leads to lesser root growth and an overall slowing even failure of crop development.
During daylight hours plants are busy creating carbohydrates from the energy the sun bestows which is technically known as photosynthesis. They are also taking in carbon dioxide and putting out oxygen.
When the sun goes down, plants shut down too. They fold their leaves, close their flowers and stomata, a phenomenon that to a human suggests they are sleeping. But not quite, they have much to accomplish before sunrise.
A new study sheds light and shows that plants actually get ready to respond to light (by growing, flowering or straining toward the light) while it’s still dark.
Researchers studied Arabidopsis, a small flowering plant commonly used in experiments, to tease apart the molecular mechanism the plant uses to respond to light. They found that while it is still dark, the plant produces and stockpiles a pair of closely related proteins (known as FHY3 and FAR1) that in turn increase production of another pair of proteins (known as FHY1 and FHL), key components of the light response mechanism.
The ability of plants and animals to measure environmental day length (photoperiod), typically by monitoring night length is called photoperiodism.
Photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light and dark periods.
The biological ability to measure photoperiod permits organisms to ascertain the time of year and develop seasonally appropriate physiological and behavioral adaptations.
It has been known since the 1940s that it is the duration of uninterrupted darkness during a 24 hour cycle that governs developmental processes in trees such as dormancy, shoot growth, and flowering.
Photoperiod controls spring and autumn phenology of trees, and also regulates developmental processes such as vegetative development and flowering.
Plants measure day length from the amount of blue and red light absorbed during the day; thus, plants integrate photoperiod and light quality in order to determine the day length.
Trees as well as other plants are classified as short-day, long-day, or day-neutral according to their response to day length.
Short-day trees flower and enter dormancy when day length shortens in late summer.
Long-day trees flower in early summer and continue vegetative growth until days shorten in the fall.
Day-neutral trees are not affected by day length at all.
Photoperiod can also influence leaf shape; surface hairiness (pubescence); pigment formation; autumn drop time; and root development, as well as onset and breaking of bud dormancy. Some types of night lighting can alter the natural photoperiod and, consequently, upset these developmental processes.
Artificial lighting, especially from a source that emits in the red to infrared range of the spectrum, extends the day length and can change flowering patterns, and most importantly, promote continued growth thereby preventing trees from developing dormancy that allows them to survive the rigors of winter weather.
Although we classify plants as short-day or long-day, in some cases, plants may actually be measuring the length of the night. That is, it can be the length of the period of continuous darkness, not the length of the period of continuous light, that determines whether or not the plant flowers.
Typical short-day plants share the following characteristics:
- They flower when the day is short and the night is long.
- They do not flower when the day is long and the night is short.
- They do not flower when the long night is interrupted by a brief period of light.
- They do not flower when the long day is interrupted by a brief period of dark.
The study of this biological need for darkness is called scotobiology.
In discussing scotobiology, it is important to remember that darkness (the absence of light) is seldom absolute.
An important aspect of any scotobiological phenomenon is the level and quality (wavelength) of light that is below the threshold of detection for that phenomenon and in any specific organism.
There are substantial levels of natural light pollution at night, of which moonlight is usually the strongest. For example, plants that rely on night length to program their behaviour have the capacity to ignore full moonlight during an otherwise dark night.
Study the plant you are growing and find out what climates it does best in, and try to simulate or optimize those light cycles.
Plants only set bloom when the night length is just right. Overworked plants obviously won’t be efficient at all, and declining health invites pests and disease to wreak havoc.
