Length of Day (how does it affect plants)

Day length helps plants to regulate their internal clock

source: g00gle

When the day length is fewer than 10 hours, most plants do not grow. Even if the temperature is kept within the ideal range — say, in a climate-controlled greenhouse — most plants will go dormant until the magical 10 hours of sunshine per day arrives.

Explanation:

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.