Grape Disease Protection for Higher Yields and Quality

February 14, 2022

California vineyard weed management

Wine, Table and Raisin Grapes

Grape growers face a variety of tough diseases in the vineyard, from Powdery mildew and Botrytis to Black rot and Phomopsis. Not only do these diseases cause serious losses in crop yield and quality, but they can also overwinter and cause problems on your vines from season to season if left untreated. Preventing, managing and eliminating these diseases is essential to protect your investment in your wine, table and raisin grapes.

Disease Threats

  • Powdery Mildew – If insufficiently controlled, symptoms of Powdery mildew can include red, blotchy areas on dormant canes; chlorotic (loss of greenness) spots on upper surfaces of the leaves; white, powdery or dusty areas; and white, powdery masses settled on the entire berry surface.
  • Botrytis – According to the University of California Cooperative Extension, Botrytis spores, if left untreated, can infect intact, healthy ‑ owners and shoots during bloom, and then develop later as fruit matures, devastating your grape quality and overall crop yield.

Relevant: Maximize Efficiency When Treating Powdery Mildew and Botrytis

Disease Control

  • Treatment – Treatment methods for both diseases are similar, which helps growers maximize efficiency for their fungicide applications and time in the ­field. To maximize return, growers can select a fungicide that is highly effective on both diseases.
  • Management and Prevention – The University of California, Davis, recommends several practices to manage Botrytis, including: leaf removal, applying fungicides properly, planting resistant varieties and canopy management.

Select a fungicide program that is highly effective on both diseases.

A closeup of hands holding wine grapes for grape disease protection

Powdery Mildew Control

In nine years of running trials (2008 to 2017), Dr. Gubler of UC, Davis, has shown Luna Experience® at bloom and Flint® Extra to be a top-rated program for grapes. In the 2016 (below) and 2017 trials, the alternation program with Flint Extra was a top-performing treatment.

Graph showing incidence of Powdery mildew with superior performance from Luna Experience combined with Flint Extra

Botrytis Control

Trial by Larry Bettiga, UCCE, Salinas Valley, 2013, shows Luna Experience helped reduce the severity of Botrytis by an average of 75%.

botytis control chart

Helps Reduce the Severity of Botrytis by an average of 75%.

Protection Means Profit

Using applications of Luna Experience at bloom provided +2,333 lb./A in higher yield over grower standard program, Commercial Block, White Hills, CA, which for the grower meant an additional pro¬ t of +$855/A.

Luna Program vs Grower Standard Program

+2,333 il/A in higher yield = +$855/A in additional profit

Botrytis Severity and Incidence in Grape

Applications of Luna Experience at bloom provided better disease control than Grower Standard Program.

Make Luna Experience® and Flint Extra® a cornerstone of your fungicide program to control tough diseases and help protect your investment in your wine, table and raisin grapes.

Read More About Disease Control

Pristine and Vivando are registered trademarks of BASF. Inspire Super, Quadris, Switch, and Vangard are registered trademarks of Syngenta. Quintec and Rally are registered trademarks of Dow AgroSciences LLC. METTLE is a registered trademark of Isagro USA, Inc.


1 Average yield gain per pound in dollars is based on California Agricultural Statistics Review