Guide for Fungicide Use for Gray Mold and Anthracnose in Strawberries
Guide for fungicide use when using the Strawberry Fruit Infection Tool:
(Also see the SE Strawberry Integrated Pest Management Guide)
Low Risk for Both Diseases: no action required; save money and time.
Moderate Risk for Both Diseases: Be prepared to put on a protective fungicide like captan if no spray was applied in the last 7-10 days.
High Risk Botrytis – If no fungicide was applied in the last 7 days:
For cases when there is no risk of anthracnose and growers need to focus on gray mold control (most fields): Initiate the first application with Switch and then rotate two or more of the following: polyoxin D; thiram; captan; CaptEvate; captan + Fontelis OR Kenja. But only thiram or captan can be applied more than twice per season due to resistance management.
Options: For a reduced fungicide program, initiate applications at FIRST bloom as above but apply subsequent sprays before predicted wet weather that favors Botrytis and according to the forecast model linked through the Strawberry IPM Guide; end applications about 26 to 30 days before expected final harvests. Research trials have documented that 4 sprays during bloom are sufficient to offer season-long Botrytis fruit rot control.
See more details and options in the SE Strawberry IPM Guide.
High Risk Anthracnose – If no fungicide was applied in the last 7 days: Use a product highly efficacious for anthracnose (e.g. Cabrio or Merivon); follow rotation and tank-mixing (e.g. usually with captan) recommendations in the SE Strawberry IPM Guide (i.e. never use Cabrio twice in a row and nor more than 4x/season).
High Risk for Both Diseases -If no fungicide was applied in the last 7 days:
A suggested sequence of sprays to control AFR and BFR is:
Application 1: early bloom spray (when covers come off and/or there are 2-4 flowers per plant
captan (medium to high rate) + Cabrio EG (12 oz)
Application 2: CaptEvate (if your resistance profile shows you do not have FRAC 17 resistance in the BFR population) OR captan alone (if your resistance profile indicates FRAC 17 resistance).
Application 3: same as application 1.
Application 4 and every 7-10 days: Rotate the following: captan; captan + Cabrio EG (12 oz).
Before predicted periods of cool and wet weather during bloom, use Switch for better Botrytis control. Use Switch with captan IF Botrytis pressure is expected to be heavy. Switch also has decent anthracnose control. Pristine, Merivon, or Cabrio show the best efficacy against AFR under high anthracnose pressure in research studies and either can be used if there is no resistance to FRAC 7. Also, if weather conditions (warm & wet) favor AFR, or you start to approach the upper limit of FRAC 11 fungicides allowed (4-5 applications), consider rotating to a tank mix of captan + Tilt.
Fungicide profiles can be assessed through the Clemson Fungicide Resistance Testing Program).
Further IPM Considerations: If there is lots of bloom, lean toward making a fungicide application rather than risk delaying. If you are less than 24 days before the last harvest, no more Botrytis sprays are needed.