Mar 8, 2021
Repar Corp. shares information about HBR, a natural plant growth regulator

Repar Corp. has issued information about  Homobrassinolide .1% (HBR) plant growth regulator with the latest product trial information on cherry trees and grapevines, both table and winegrapes.

According to a news release, HBR is a  a natural plant growth regulator (PGR), it promotes cell division, and acts synergistically with other plant hormones to increase photosynthesis and enzymes responsible for synthesis of nucleic acids, proteins and sugars.  The end results are an increase in crop yield while maintaining plant health and is fully biodegradable and environmentally safe.

Production trials provide evidence that HBR promotes increased fruit size, yield, color, sweetness, stem strength, fruit firmness, and hastens maturity.  Sweet cherry field trials with HBR demonstrated increased yield with average larger size and weight of the fruit.

The darker fruit color of cherries treated with HBR indicates higher dissolved sugar or BRIX for better taste and aesthetic appeal.  Also increased stem strength demonstrates the ability of HBR treated cherries to withstand mechanical stress while fruit firmness helps reduce the risk of damage during harvest and handling.

A bigger benefit recorded on cherry trees treated with HBR is the fruit matured a week earlier than those treated with other PGR’s.  These advantages of HBR provide the grower with economic benefits.

The cherry fruit trials in 2016 indicated the HBR application rate with the most beneficial results for economy and fruit production is 13.3 fluid ounces per acre, the recommended label rate.  The best time to apply HBR on cherries is when the fruit color development is approximately translucent green to straw color.

Field trials on Scarlet Royal table grapes were conducted to evaluate the effects of HBR to enhance ripening. Additionally, these studies tested the effects on increasing soluble solids known as BRIX, enhancing cluster color, and berry hue.  The results for all trials demonstrated that HBR is most effective with two applications at 13.3 fl. oz./acre on grape vines.

The initial replicated spray applications were during late bloom to early shatter while the second sprays were made approximately one week after bloom, when berry diameter was approximately 3 mm.  HBR improved yield, fruit firmness, color, and hastened maturity by a week. Additionally, HBR is compatible in tank mixes with other PGR’s, pesticides, fertilizers, and micronutrients.

Repar has additional trial data with HBR on strawberries, blueberries, almonds and more. For more information on HBR, please visit the Repar website at

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