ProTone® Becomes the Colorful Choice of Growers

Ideal for application on red table grape and wine grapes.

Offered in both granular and liquid formulations and available for use in organic operations, ProTone® and Excelero®:

  • Enhance color development in red table grapes and wine grapes

Active Ingredients
ProTone contains the naturally occurring plant growth regulator (PGR), S-abscisic acid (S-ABA), which controls stomatal closure, water relations, and photosynthesis.

How ProTone Changed the Game
In the 1990s, many grape-growing regions needed an innovative method for coloring grapes that met marketing requirements and consumer demands. The standard coloring tool, ethephon, has come under increasing regulatory and consumer scrutiny regarding residues.

While it had been reported in scientific literature that application of S-ABA could enhance the red coloration of table grape cultivars, there were no S-ABA products approved and available for use in agriculture given the difficulty and cost of its production. Valent BioSciences was the first to produce, register, and commercialize S-ABA, branding it ProTone (Excelero in some regions).

Creating Accessibility
Valent BioSciences and its predecessor, the Agricultural Products Division of Abbott Laboratories, first investigated the potential use of S-ABA in agriculture in the 1990s, but the supply was limited, the cost was high, and more work was required to develop consistent, efficacious use patterns.

In 2002, Valent BioSciences established collaborations to develop both cost-effective manufacturing and use patterns for S-ABA in agriculture. The company’s microbiologists, fermentation scientists, and chemists worked to develop and industrialize the production of S-ABA by fermentation. The formulations research group developed effective, user-friendly formulations that can be used in both conventional and organic markets. Development of an S-ABA production method and the ProTone formulations was groundbreaking and allowed for S-ABA, one of the five classical PGRs, to be produced on an industrial scale for the first time.

Working with viticulture researchers around the world, Valent BioSciences developed reliable application rates and timings to promote red color development of key table grape cultivars and improve marketable yield. ProTone has a very dramatic effect on coloration of grape clusters and was game-changing for table grape growers and exporters, giving them an effective and natural option for coloring that eliminated residue concerns. Without ProTone, red table grape growers sometimes cannot harvest 20-25% of the crop due to poor coloration or may harvest at little to no profit to be used for juice. With its consistent effect in improving red color, ProTone allows more fruit to be harvested and marketed as high-quality table grapes.

Providing Education
With the launch of the new product came the need for user education when it was clear that ProTone only colors where the fruit is sprayed. Valent BioSciences conducted technical training with growers to ensure the most effective use of the product, informing growers of the importance of the directed spray application to the fruiting zone to achieve full coverage of entire grape bunches, as well as appropriate table grape viticulture practices such as vine training, fruit load, and canopy management to promote proper coverage and efficacy. Because of Valent BioSciences’ technical experience, expertise, and reputation in the industry, growers trusted the potential of ProTone and worked together to make it an important tool in the table grape industry.

The first countries to register ProTone were Chile, the U.S., and Australia. Since then, ProTone has been registered in additional important table-growing grape countries around the world and new uses have been developed. There are still countless opportunities to develop additional uses for ProTone and S-ABA to provide solutions to unmet grower needs, and Valent BioSciences is committed to bringing these sustainable solutions to the marketplace.

Since the launch of ProTone on table grapes, Valent BioSciences has continued to develop new uses for S-ABA.