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Describe how Poinsettias are grown for Christmas in relation to their critical photoperiod?
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∙ 13y ago
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How long do poinsettias live?
A couple years is how long poinsettias (Euphorbia pulcherrima) can grow.Specifically, poinsettias are perennial shrubs in their native southwest Mexican and Central American homelands. Outside that native range, they tend to be grown as annuals whose life and death take place over the course of a year. But they have the potential to live much longer, if such critical conditions as appropriate levels of heat, light intensity and moisture are met.
What is the critical analysis of Feeding the poor at Christmas?
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How much darkness do poinsettias need?
Twelve (12) hours 20 minutes of uninterrupted darkness for five (5) days straight is the amount of darkness that poinsettias (Euphorbia pulcherrima) needs in order to bloom.Specifically, that is the requirement that must be met sometime between September 20 and October 20 in order for poinsettias to bloom in December. Such is the natural bloom cycle for poinsettias as long as other critical conditions such as air and soil moisture, light intensity, nutrition and temperature are met. But in fact, anytime that poinsettias undergo the above-mentioned short day/long night cycle they have the potential to see the flowering process initiated and their modified leaves change in color from green to red 65-85 days later.
What stimuli will cause a mum plant to bloom?
Most chrysanthemums are obligate photoperiodic plants. That means that they are stimulated to bloom only by the length of daily darkness, which is known as the photoperiod. Most chrysanthemums are what is called 'short day' plants, although it might be more accurate to call them 'long night' plants. They bloom only when the daily nighttime photoperiod lengthens to a critical number of minutes. Preparation for flowering is initiated in periods of shorter nights (like in summer), when the buds that will eventually become flowers are created. The buds then lay dormant until the photoperiod lengthens to a critical point; the dormant buds awaken, grow and open to form the plant's blooms. To cause a mum to bloom out of season, you need to provide it with the night length required to stimulate flowering. It can be kickstarted in the summer by covering the plant at the beginning or the end of the day for several hours. This effectively increases the nighttime for the plant and can initiate blooming. In greenhouses, horticulturists can force photoperiodic plants to bloom at any time of the year by artificially controlling the length of light and darkness. This allows us to have mums in the spring and poinsettias in the winter.
What do of the terms catastrophic critical marginal negligible describe in the risk assessment matrix?
Level of damage
What is used to describe the light gathering or light collecting ability of an optical fiber?
a. Critical angle
What is the term that is used to describe a key factor required to start a fission reaction?
critical mass
What do the terms catastrophic critical marginal and negligible describe in risk assessment matrix?
Level of damage
What do the terms catastrophic critical moderate and negligible describe in the risk?
Level of severity of adverse event's effect
What The terms catastrophic critical moderate and negligible describe in the risk assessment?
Level of severity of adverse event's effect
What do the terms catastrophic critical and negligible describe in the risk assessment matrix?
Level of severity of adverse event's effect
What do the terms catastrophic critical moderate and negligible describe in the risk assessment?
Level of severity of adverse event's effect
