GAUGING CHILL BETTER:Using a new system the chill portions model can improve growers' accuracy

摘要

WITH 2014 WRAPPED UP, it's a good time to take stock of the impacts ofthe warm winter of 2013-14.Last winter was a clear demonstration that simply counting chill hours is not a great way to approximate how California fruit and nut trees are affected by chill. A newer way of counting, the chill portions model, can help growers better track chill andanticipate low chill years.Chill accumulation last winter fell behind in January and never caught up. Many orchards showed classic symptoms of low chill and suffered decreased yields as a result. According to the chill hours model, last winter was actually an average chill winter. The trees obviously did not get the message. The chill portions model, on the other hand, showed chill down 25% across the Central Valley.