Vol. 119 (2006): Proceedings of the Florida State Horticultural Society
Citrus

Spatial analysis of freeze events in Florida

Clyde W. Fraisse
University of Florida,

Published 2006-12-01

Keywords

  • citrus,
  • cold weather,
  • surface trend analysis,
  • GIS

Abstract

In spite of the mild winters, severe cold weather occurs in Florida when the polar jet stream moves further in the southern region of the US. Oranges are usually damaged when the fruit are exposed to temperatures below -2C (28F) for 4 hours or more. The main objective of this study was to understand the spatial distribution of two major freezes that severely affected the citrus industry during the last century and to determine their impact on the citrus production areas of the state. Minimum temperature data collected at individual weather stations during the freezes of December 25, 1983 and January 21, 1985 were analyzed and interpolated using surface trend analysis. The resulting maps were analyzed in conjunction with land use maps to estimate the area of citrus production impacted by different temperature ranges. In 1985, 100% of the citrus production areas located in the northern production zone was subjected to temperatures below -2C (28F). In the central, western, Indian River and southern zones, the fractions of the production areas affected were 70%, 52%, 52%, and 6%, respectively. During the freeze of 1983, the fractions of the production areas affected were 50%, 57%, 42%, 3%, and 1% for the northern, central, western, Indian River, and southern production zones, respectively.