Effect of Timing of Preharvest Fungicide Applications on Postharvest Botrytis Fruit Rot of Annual Strawberries in Florida

Preharvest fungicide applications for postharvest control of Botrytis fruit rot were evaluated over four seasons on annual strawberry in Florida. In the 2002-2003 season, applications of Switch or Elevate immediately prior to harvest were ineffective for controlling Botrytis fruit rot postharvest. In the 2003-2004 season, applications of Captevate or Switch made immediately prior to harvest reduced postharvest Botrytis fruit rot, but not as much as applications made during the flowering period. Similarly, in the 2004-2005 season, Captevate and Pristine provided some control of postharvest Botrytis fruit rot when applied immediately before harvest. In both the 2003-2004 and 2004-2005 seasons, applications made during the flowering period were more effective for postharvest Botrytis fruit rot control than those made prior to harvest. In the 2006-2007 season, applications of Captevate, Thiram, Scala plus Captan, or Switch alternated with Captan during the flowering period provided good control of postharvest Botrytis fruit rot. Although not as effective as bloom applications, fungicides applied immediately before harvest may have some benefit for controlling Botrytis fruit rot if the sprays during the bloom period were not made.