Degree-days Estimator to Predict Phenological Stages (DJPheno)
DJPheno software is used to determine the required parameters of a bioclimatic model based on the degree-days approach. These parameters are the base temperature of a living organism (plant or insect), and the number of degree-days required to reach clearly defined stages of development of this organism. The base temperature is the minimum temperature at which the organism can develop. The number of required degree-days predicts biological events in the life of this organism.
Firstly, DJPheno computes the average of degree-days required to reach given thresholds for all data sets, and that constitutes the model. Then, a comparison is done between field observations and model predictions. Comparative statistics are displayed and it is then possible to check the quality of model predictions.
To use DJPheno, it is necessary to have scouting data (insects) or phenology observations (plant) that will be matched with daily weather data for each site and each year of observed data. The software estimates the base temperature of the organism according to one of six methods loaded in the software for calculating degree-days and a statistical criterion selected. If the base temperature was measured experimentally, it is possible to use that data item rather than the one mathematically determined by the software.