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Biorationals – A Sustainable Postharvest Decay Control Solution

The use of biorationals for disease control is gaining momentum in the postharvest industry. As fungicide resistance continues to be an ongoing challenge affecting postharvest decay control, packing houses are looking for biologically derived fungicide alternatives.

What is a Biorational?

The term biorational is used to characterize a broad range of low environmental impact substances or products related to agriculture and plant health as well as other industries. They are typically biologically-derived, or if synthetic, the structure is similar and functionally identical to a biologically-occurring material.

One example of a biorational fungicide is BioSpectra 100 SC®, one of Pace’s newest OMRI certified biorational products. This fungicide consists of the active ingredient, natamycin, which is produced via fermentation of the bacterium Streptomyces natalensis and other related species.

Originally isolated from soils collected in South Africa in 1955, natamycin has since been used as a food preservation tool for decades due to its broad-spectrum inhibition of yeasts and molds. As a biorational fungicide, natamycin provides a new mode of action, inhibiting growth of some of the most important postharvest pathogens affecting citrus, cherry, pome, and stone fruit production.

Why Biorationals?

Biorationals provide a lower impact to the environment compared to some synthetic chemistries. Its use in agriculture has been focused primarily on pre-harvest application, aiding in crop stress management, enhanced plant physiology benefits, root growth management, or as an alternative control agent to pesticides and antimicrobials. After understanding its benefits, the attention has turned to the postharvest industry and how biorationals can provide natural decay solutions.

Compared to synthetic postharvest products that deliver decay control, biorationals outperform through their resistance tolerance, which is beneficial to applicators who are longing for a natural fungicide alternative.

How Does it Work?

Biorational fungicide binds to ergosterol in the fungal cell membrane, affecting the transport of proteins and glucose across the membrane, leading to cell expiration. This in turn affects the spore germination and mycelial growth of target fungi, preventing the development of certain postharvest diseases. Natamycin provides broad spectrum control for many of the challenging postharvest diseases that affect the citrus, pome, and stone fruit industries:

  • Blue mold (Penicillium spp.), gray mold (Botrytis cinerea), and green mold (Penicillium digitatum)
  • Sour rot (Geotrichum spp.), mucor rot (Mucor piriformis), Rhizopus rot (Rhizopus stolonifer), and brown rot (Monilinia fructicola)

What are Biospectra’s Benefits?

  • Proven safety as a food preservative
  • Expected to be exempt from tolerance
  • Broad-spectrum against all major postharvest diseases
  • Excellent performance as a solo and mixture
  • Controls fungal strains with resistance to other chemical classes
  • No known cross-resistance
  • Only fungicide that controls Mucor rot
  • OMRI certified

Today, nearly half of all fresh produce is wasted in the U.S. alone. Thirty to 40% of this waste occurs along the supply chain before it even reaches the consumer. We understand that biological solutions play a pivotal role in protecting the quality and marketability of fresh produce. Pace is proud to bring innovative, sustainable solutions to customers and the fruit packing industry.

For more information about biorationals, please contact your local Pace representative or visit us at

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