UW Extension Ag Weather

lake mendota tree

Tree Pest Development

Tree Pest Development

Development of tree and shrub pests can be estimated using a modified base 50 F degree-day calculation. For these pests the degree-day summation is started well before the growing season.

A degree day is a unit of heat for each degree above the base temperature in a 24 hour period.Degree day accumulations can be used to determine distinct phenological events such as when specific plants will bloom, when to plant vegetables, and when insect pest outbreaks will occur.