Don't let hidden threats spoil your blueberry harvest! Botrytis grey mold, caused by Botrytis cinerea, is like an invisible thief, waiting for the right moment to strike. It thrives and infects during cool, wet conditions and can secretly infect your berries during bloom, sitting dormant and unnoticed until the crop ripens. Because of this, getting ahead of Botrytis early is the key to protecting harvestable yield and your bottom line. This is where the one-two punch of Allegro^® and Miravis^® Prime fungicides can help.

Go with Allegro

Allegro (Group 29) has activity on mummyberry, anthracnose, and Botrytis. With a 30-day PHI, it is a great tool to use heading into bloom, or at early bloom as it covers key fruit diseases. As a group 29, Allegro is also a different mode of action from most Botrytis fungicides, which helps to prevent resistance.  The cool part about Allegro is that it has activity against multiple aspects of Botrytis development (spore germination, appressorium formation, hyphal penetration, and sporulation) so it can also be used post-bloom on late varieties for a post-bloom clean up. As you can see, there are many reasons why Allegro is ready to go!

Miravis^® Prime time

Miravis^® Prime (Group 7 + 12) is powered by ADEPYDIN and the trusted active ingredient, fludioxonil. It is an excellent choice as the first bloom spray for Botrytis protection in blueberries. Why? It works in two ways:  the ADEPYDIN® component has systemic (translaminar and limited acropetal) movement that affects mycelial growth, spore germination, and germ tube growth, while fludioxonil acts on the plant surface, limiting spore germination and germ tube growth.

Miravis^® Prime and Allegro^® are two very effective fungicides that help protect developing blueberries from Botrytis infection, translating into higher yields and better post-harvest quality: 

• In research authorization trials on two commercial farms in British Columbia in 2020, fungicide programs that included two applications of Miravis^® Prime had 11 to 13% higher blueberry yields than the growers’ standard program*. 
• Miravis^® Prime (0.4 L/ac) and Allegro (0.6 L/ac) reduced the incidence of Botrytis fruit rot up to 10 days after harvest in Canadian small-plot trials (see below).

Source: Internal contract replicated small-plot trials conducted in Nova Scotia (CAOP0F8032022) and Ontario (CAOP0F8042023) in 2022-2023, n = 2. Two or six applications of Allegro (1.46 L/Ha) and Miravis® Prime (1 L/Ha) were applied to highbush blueberries beginning at bloom. Data for CAOP0F8032022 was gathered 6 days after harvest; such data is shown in the chart as 5 DAH for simplicity in combining the data from both trials.¹

Wondering about Switch^®? 

Not only can Botrytis infections be sneaky at time of infection, but Botrytis cinerea is a pathogen with high resistance risk, meaning that repeatedly using the same fungicide groups to battle it may lead to those tools not working or not working as well. To reduce the risk of resistance, use fungicides from different FRAC Groups when targeting Botrytis. For example, when used together in a fungicide program, Miravis^® Prime and Allegro can give you a solid foundation for fungicide resistance management:

• Wondering where Switch^® fits? Switch contains fludioxonil (Group 12) and cyprodinil (Group 9). Recent sensitivity testing shows that B. cinerea isolates collected from berries in BC show a high level of insensitivity to cyprodinil.² There is full cross-resistance among Group 9 active ingredients. For that reason, consider a switch to Miravis^® Prime for two potent modes of action at bloom. 
• Miravis^® Prime has built-in resistance management with two modes of action against Botrytis: ADEPIDYN^® (FRAC Group 7) and fludioxonil (FRAC Group 12).  
• Allegro contains a different mode of action, fluazinam (Group 29), which has a low resistance risk.   
• Looking for something completely different? Multi-site chemistries like Captan L are also a great choice to mix things up when targeting Botrytis. Consider using Captan in those warm wet years when Botrytis is targeted many times.  
• To read more about FRAC guidelines for Botrytis resistance management, visit this link.

Curious and looking to learn more? Chat with your local input supplier or contact your local Syngenta Rep using the Find Your Rep tool.

For more information, visit Syngenta.ca, contact our Customer Interaction Centre at 1-87-SYNGENTA (1-877-964-3682) or follow @SyngentaCanada on social media.

¹Performance evaluations are based on internal trials, field observations and/or public information. Data from multiple locations and years should be consulted whenever possible. Individual results may vary depending on local growing, soil and weather conditions. At time of print, Maximum Residue Limits (MRLs) had been established for fluazinam and pydiflumetofen for export markets in the United States and Japan. Please see the Foodchain ID Regulatory Limits by BCGlobal database at https://bcglobal.bryantchristie.com/db#/pesticides/query for a complete list of MRLs. Should you need additional information on export market MRLs, please consult with Syngenta to receive the most up-to-date information. Do not make more than two applications of any ADEPIDYN^® containing product (e.g. Miravis^® Neo and Miravis^® Prime) on blueberries per year. 
²Source: Internal Syngenta fungicide sensitivity trial (mycelial growth assay), Canada, n = 1 (19 isolates). Isolates collected in 2020-2022 from blueberries and raspberries in British Columbia and provided by Dr. Rishi Burlakoti (AAFC). Performance evaluations are based on internal trials, field observations and/or public information. Data from multiple locations and years should be consulted whenever possible. Individual results may vary depending on local growing, soil and weather conditions. Always read and follow label directions.

Always read and follow label directions. Miravis^®, Switch^®, and the Syngenta logo are trademarks of a Syngenta Group Company. Allegro^® is a trademark of ISK Biosciences Corporation.