Presentation on theme: "Master Gardener Class 2011 Carol Fryer. How I Did My Research GoogleGoogle search by topic and specify a university or extension website Search examples:Search."— Presentation transcript:
How I Did My Research GoogleGoogle search by topic and specify a university or extension website Search examples:Search examples: degree days site:edu growing degree days site:vt.edu degree days site: ext.vt.edu
So What are Growing Degree Days? Growing Degree Days : Integrated Pest Management tool Tracks and predict stages of insect development based on temperature Uses a mathematical calculation system Can compare from year to year Easy and fun to do!
What does it involve? * Record daily high and low temperatures and find an average temperature for the day. Example: Example: 70º Max & 50° Minimum temp/2 = 60° average daily temperature *Subtract 50º Base Temperature from average temperature: 60 - 50 = 10 Growing Degree Days (GDD) *Add the GDDs for the Accumulated Growing Degree Days(AGDD) and compare to a chart of insect development by degree days.
Mathematical Equation of GDD Max temperature + Minimum Temp /2 minus Base Temp = Daily GDD 70°(MT) + 50°(min t) /2 = 60°– 50°(BT) = 10 GDD
Summary – GDD & Insect Control Record daily high and low temperatures and calculate the average temperature Subtract the base temperature from the daily average Keep a daily accumulated total of the Growing Degree Days Check plants for signs of pests Use list of insect development to predict time periods for potentials pests