High spring temperatures decrease peach fruit size

The growth and productivity of peach fruit can be limited by many factors, including weather. Previous research indicated that early-spring temperatures for 30 days after bloom have a strong effect on early peach fruit growth, and both the time and potential fruit size at harvest. We analyzed fruit-size trends of three major cultivars in the California fresh- market peach industry (Flavorcrest, Elegant Lady and O'Henry) over a 20-year period to determine if there is a clear relationship between early- spring temperatures and packed fruit sizes industrywide. This research confirmed two significant trends: the size of packed fruit has increased over the 20-year period between 1985 and 2004, and high early-spring temperatures tended to decrease the size of packed fruit at harvest for any given year.