Mehr Chilling für Obstbäume in wärmeren Wintern? Modellierung des Kältereizes – unter dem Einfluss des rezenten Klimawandels – für das Meckenheimer Obstbaugebiet


The objective of this study was the calculation of winter chill for fruit trees in the Meckenheim fruit growing region for all winters since 1958 and the evaluation of long-term trends in response to global warming. A further objective was the comparison of three winter chill models, the Chilling Hours Model (Chilling Hours—CH), the Utah Model (Chill Units—CU) and the Dynamic Model (Chill Portions—CP) with respect to temporal trends and seasonal variation in chilling intensity. To meet these objectives, about 120,000 hourly temperature measurements from Klein-Altendorf were correlated with daily temperature extremes. From this relationship, a long-term record of 466,000 hourly temperature data was constructed and used to calculate winter chill between 1st October of each year and three dates of the following year for all winters since 1958/1959.