GEOLOGY

Detailed explanation-1: -Dormancy Breaking Chemical Compounds. Under temperate climatic conditions, deciduous fruit trees need certain chilling hours during winter for dormancy breaking by the beginning of spring.

Detailed explanation-2: -Typically, temperatures between 32°F and 50°F can help fulfill the chilling requirement of many plants, but the most efficient temperatures for satisfying a plant’s need for cold are between 32°F and 45°F. When temperatures dip below 32°F, very little, if any, chilling is received by the plant.

Detailed explanation-3: -However, the best temperature for chilling is not the extreme cold. Effective chilling temperatures to terminate dormancy are generally between 32 to 45O F (it is generally agreed), and approximate hours of chilling required to break dormancy will vary according to species and cultivar.”

Detailed explanation-4: -The chilling requirement of a fruit is the minimum period of cold weather after which a fruit-bearing tree will blossom. It is often expressed in chill hours, which can be calculated in different ways, all of which essentially involve adding up the total amount of time in a winter spent at certain temperatures.