Growing Degree Days are a measurement of the growth and development of plants
and insects during the growing season. Development does not occur at this time
unless the temperature is above a minimum threshold value (base temperature).
The base temperature varies for different organisms. It is determined through
research and experimentation. The actual temperature experienced by an organism
is influenced by several factors. These factors affect growth and development.
For instance, depending on the weather, an organism's temperature may be a few
degrees more or less than that recorded. An organism may spend its time in the
shade or under direct sunlight. The fertility and nutrient content of the soil
directly affect the growth rate of insects and plants. The presence of weeds
and precipitation may indirectly influence development. Due to these factors and
some other scientific considerations, a base temperature of 50 degrees
Fahrenheit is considered acceptable for all plants and insects.