Because of some unique characteristics, biorationals provide growers with some valuable tools late in the season. Plant growth regulators such as Retain can delay harvest time in stone fruits, allowing flexibility in labor management. Delaying harvest can also increase yield – fruit on the tree can increase 1% of its weight per day. Depending upon the product and crop, plant growth regulators provide a variety of other benefits at harvest time, including enhanced fruit storageability, reduced pre-harvest fruit drop and improved skin finish.
Residue levels are becoming of increasing concern among consumers, and maximum residue levels have been significantly lowered, particularly in Europe. Most biorationals are exempt from residue limits, so they are safe to use very late in the season, providing protection for a crop close to harvest. Because biorationals have the shortest worker re-entry interval allowed by law under U.S. EPA standards, they are ideal to use for late season pesticide applications when timing of harvest is critical. Biorationals are important tools for greenhouse operators for the same reason, since pesticide applications are made in enclosed areas.