Strawberry Fungicide Program Suggestions
Here are a variety of suggestions based on our experience as well as information gathered from winter conferences and industry contacts. In addition, consult your local cooperative extension office for specific state recommendations.
1. ALWAYS CHECK THE LABEL regarding annual application limits, resistance management and labeling for your state. Good websites for that information are www.CDMS.net. or agrian.com.
2. RESISTANCE MANAGEMENT IS CRITICAL FOR MAINTAINING CHEMICAL EFFECTIVENESS. Avoid making sequential applications of the same class fungicides. Information on fungicide class distinctions can be found at http://frac.info and look for 2020 FRAC code list. We have also included FRAC codes with specific fungicides in this article.
3. USE CAPTAN OR THIRAM WITH VARIOUS FUNGICIDES, whenever possible, for broadspectrum control and resistance management. PLEASE NOTE: Mixing Captan with any oil-based material will cause leaf phytotoxicity. This would include other fungicides or secticides.
4. OXIDATE HAS PROVEN TO BE AN EFFECTIVE BROAD-SPECTRUM FUNGICIDE control and is labeled for organic growers.
5. A NEW PREVENTATIVE BIOFUNGICIDE from Bioworks, BotryStop has potential to fit into both organic and conventional spray programs. We have started testing this product at Nourse Farms and initial results are encouraging. For additional information see the Bioworks website at www.bioworks.com.
6. CHECK AND CALIBRATE SPRAYER. Choose tips and application rates (gallons per acre) based on coverage needed, which can change based on growing canopy. If you don’t have good spray coverage – you won’t have good control. Adjuvants can assist with coverage.
BLOOM APPLICATIONS
Bloom applications are the critical time to effectively control botrytis, and should begin at 5 - 10% bloom. Because of the importance, a spray schedule of 7 to 10 days is recommended. During excessive wet periods, the schedule might be reduced to a 4 or 5-day schedule.
Usually 4 or 5 applications can accomplish the job for the season.
Bloom Recommendations (FRAC code)
• Switch (9 + 12) + Captan (M4) & Oxidate
• Elevate (17) + Captan (M4) & Oxidate
• Fracture (M3) + Oxidate
• Merivon (7 + 11) + Captan (M4) & Oxidate
• Scala (9) + Captan (M4) & Oxidate
• Inspire Super (3 + 9) + Captan (M4) + Oxidate
LEATHER ROT CONTROL
For leather rot control during extended wet periods, when frost protection is necessary and especially if leather rot occurred last year, add Ridomil Gold as one of the fungicides in your bloom spray program beginning at first bloom. Straw mulch can greatly assist in minimizing water splashing that can spread leather rot. Growers can also consider a phosphorous acid product.
AFTER BLOOM APPLICATIONS – GREEN FRUIT THROUGH HARVEST
After flowering, the threat of botrytis infection decreases. Green fruits are not as susceptible to infection. If spray coverage was poor or lacking (including too long an interval) during bloom, infection could result. Also, Anthracnose can be a problem during warm, wet conditions. As infections are often difficult to control once present, a preventative approach may be best, especially if it was present during prior harvests.
After Bloom Recommendations (FRAC code)
• Switch (9 + 12) + Captan (M4) & Oxidate
• Abound (11) + Captan (M4) & Oxidate
• Elevate (17) + Captan (M4) & Oxidate
• Cabrio (11) + Captan (M4) & Oxidate
• Merivon (7 + 11) + Captan (M4) & Oxidate
If necessary to continue coverage beyond two sprays, alternate the application of the above chemicals with an application of Switch, Elevate, Thiram or Captan.
NOTE: There are reports of botrytis resistance to some control products as well as cases of anthracnose resistance to QOI chemicals. If you are seeing reduced control for a particular product, consult your local cooperative extension office.
IMPORTANT REMINDER: Refer to the label and your state’s particular recommendations, as states have varying regulations regarding timing, rates and allowances for any spray program.
Organic or ORMI listed fungicides: Copper products, Oxidate, BotryStop, Aremicarb, Serenade/Sonata.