Control of Grape Powdery Mildew with Synthetic, Biological, and Organic Fungicides: 2021 Field Trials
Akif Eskalen – UC Davis
This trial was conducted at the University of California, Davis Plant Pathology Fieldhouse Facility from April to July 2021. Treatments were arranged in a completely randomized block design, and spraying concluded on July 9, based on the berry Brix level. Disease incidence and severity were evaluated on July 20, 2021.
The trials included both soft chemistry products and synthetic fungicides, with spray intervals ranging from 7 to 21 days.
Powdery mildew, caused by the biotrophic fungus Erysiphe necator, is a polycyclic disease that significantly impacts grape quality and yield. It is considered one of the most economically important grape diseases worldwide. This report summarizes the findings of our annual powdery mildew fungicide trials on Vitis vinifera (cultivar Chenin Blanc, 10 years old). Along with Chardonnay, Muscat Blanc, Roussanne, and Carignane, Chenin Blanc is among the most susceptible wine grape varieties.
Magna-Bon CS 2005 Research Trial Results
As shown in Table 1, with an infection rate of 71%, CS 2005 achieved 83% control of powdery mildew!
In Table 2, with an infection rate of 46%, CS 2005 demonstrated an impressive 95% control of powdery mildew!
Application Rate: Magna-Bon CS 2005 should be applied at 20 oz per 100 gallons of water per acre at 14-day intervals for optimal disease control.
Combat Brown Rot, Downy Mildew, Phomopsis, and Powdery Mildew in Grapes with CS 2005!
Click here for application rates and instructions.
Click Here to Download the Powdery Mildew Research Trials Information Sheet.
More proof that CS 2005 can help you in your vineyard…
JW Ray had issues with powdery mildew with his grapes at JOLO Winery, located in Mount Pilot, North Carolina. JOLO Winery is rated in the Top 7 wineries located outside of California according to Trip Advisor!
Here is JW’s message to Magna-Bon:
Frank, JW Ray here up in North Carolina. Just reporting that I’m in love with your product! I’ve sprayed it on three varieties (Vidal Blanc, Chambourcon, Traminette) known to have sensitivity to copper and they have performed spectacularly. I’ll be at 20 ounces of CS 2005 with 75 gallons of water per acre but it eradicated the early onset of powdery mildew!
Materials and Methods from Powdery Mildew Research Trials
A. Experimental design
- Experimental design – Randomized complete block design with 4 replicates = 1 treatment
- Experimental unit – 2 adjacent vines = 1 plot
- Row and tree spacing – 11 ft (row) and 7 ft (vine) Plot unit area – 154 ft2
- Area/treatment – 616 ft2 or 0.0141 acre/treatment (4 replicates = 1 treatment)
- Volume water/Acre:
– 50 gallons =0.71 gal/4 reps
– 100 gallons (late April,) = 1.41 gal/4 reps
– 150 gallons (late May) = 2.12 gal/4 reps - Equipment -Stihl SR 430 mist blower backpack sprayers
To read Akif Eskalen full report, click here!
