Strawberry fruit anthracnose

Getting ahead of anthracnose

Fruit anthracnose (Colletotrichum acutatum) can wreak havoc in strawberry fields, especially in day-neutral production systems, when summer weather conditions tend to be warm and humid. In a season with frequent rains, the problem worsens as splashing gives spores a free ride to new infection sites in the canopy. Management requires an integrated approach – purchasing disease free plants to prevent introduction, drip irrigation to limit spread within fields, managing residue to reduce overwintering inoculum, and fungicides to prevent infection and spread.

Which fungicides can help?

Syngenta has three products available to help manage anthracnose, and the other important fruit rot, Botrytis, during bloom and fruit production – Miravis^® Prime (ADEPIDYN^® + fludioxonil), Switch^® (cyprodinil + fludioxonil), Inspire Super^® (difenoconazole + cyprodinil), and Captan L (captan).

Product	FRAC Group	Application rate (/acre)	Control	Suppression	PHI
	7+12	0.4 L	Anthracnose, Botrytis		1
	9+12	775 to 995 g	Anthracnose, Botrytis		1
	3+9	1.161 to 1.475 L	Botrytis	Anthracnose	1
	M04	2.34 L/ac	Botrytis, leaf spot

High time for Miravis^® Prime

Miravis^® Prime has recently taken the top spot as a standard for fruit rots in strawberries in Canadian production with its’ potent fruit rot protection and powdery mildew activity:

Source: Internal and external data, WV (PDMR 16:PF008 2021) and FL USVNT5152019. Products were applied four times on a 14-day interval (PDRM 16:PF008) or four times within a 14-spray program alternating with Captan Gold^® on a 7-day interval (USVNT5152019).

Have you hear of Inspire Super?

Specifically for anthracnose protection, and to give fludioxonil a break, Inspire Super is an option. During high-risk periods, consider tank mixing with a Group M fungicide. Inspire Super reduced anthracnose fruit incidence by 79% in Québec trials.

Source: External replicated trials conducted in QC, 2015 & 2019, n = 2 (AAFC15-020E-194, AAFC15-020E-375). Three or four applications of Inspire Super (1.475 mL/Ha) were applied. Fruit incidence data 8 or 12 days after the last application.

Keeping tools in the toolbox

Fungicide resistance is an ongoing concern with fruit anthracnose and Botrytis. For example, anthracnose resistance to Group 11 fungicides has been reported in Ontario and Quebec, and Botrytis resistance to Group 9 fungicides. So, how do we extend the life of remaining tools? A key practice is to follow FRAC guidelines for each mode of action group – including alternating and mixing FRAC groups. For Miravis Prime, Switch, and Inspire Super, this means rotating products to allow no more than two sequential applications of any Group 7, 9, or 12 containing fungicide. Also using group Ms like Bravo at season ends, and Captan L in-season to break up those single site groups is an excellent way to slow resistance.

Syngenta recently wrapped up a two-year resistance monitoring program to test the sensitivity of C. acutatum strawberry isolates to fungicides, and those results were considered for the product suggestions in this article. If you would like more information on the local results, or want to understand more of our strawberry solutions reach out to your local rep.

Reach out to your local rep to grab a strawberry Quick Reference Guide for strawberries.

For more information including articles, resources and videos on resistance management, check out Manage Resistance Now. This is a collaborative effort of industry, academia and government experts, brought together by CropLife Canada, to raise awareness and promote the adoption of strategies to manage weed, insect and disease resistance.

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. ADEPIDYN^®, Miravis^®, Switch^® and the Syngenta logo are trademarks of a Syngenta Group Company. Other trademarks are property of their respective owners.