Back to top

Plant Growth Regulators

Printer-friendly versionPrinter-friendly version
Written by: 
Jon Clements

ReTain® Plant Growth Regulator (Valent Biosciences) is labeled for harvest management and improvement of fruit quality of peaches and nectarines.

The label specifies: Depending on cultivar, orchard conditions, and grower objectives, one or more of the following benefits will be associated with ReTain...

  • Improved harvest management
  • Additional time for increase in fruit size
  • Maintenance of fruit firmness
  • Reduced preharvest fruit drop
  • Improved fruit quality
  • Enhanced storage potential 

Rate and Timing: Apply one pouch of ReTain per acre one to two weeks prior to the anticipated beginning of the normal harvest period of untreated fruit

Water Volume: ReTain efficacy requires that fruit and foliage receive thorough spray coverage. To ensure thorough coverage adjust water volumes based on tree size and spacing and use calibrated spray equipment (i.e., orchard air blast sprayer). Excessive spray application volumes that result in spray runoff will reduce product performance. In most cases, 100 gallons per acre has been shown to be effective.

Use of Adjuvants: For optimal response, use ReTain with a 100% organosilicone surfactant. Use a final surfactant concentration of 0.05 to 0.1% (v/v) in the spray tank. To reduce foaming, add the adjuvant last and minimize agitation.

Harvest: The normal harvest period for a particular orchard block refers to that time when fruits not treated with ReTain would be harvested. To help determine the beginning of the normal harvest period, refer to historical trends for harvest dates and the “days from full bloom to harvest” interval for each cultivar in your area, and closely monitor the fruit maturity development for the current season.

Additional Notes: Pre Harvest Interval (PHI): ReTain has a 7 day (PHI) for labeled Stone Fruit.