Botrytis is a disease that needs to be controlled early, says Dr. Kathie Kalmowitz, Technical Specialist, Turf & Ornamentals for BASF. “And with Botrytis, it isn’t just the chemical control you need, but you must also consider your watering program and growing temperatures,” she says. Controlling the moisture in the greenhouse with good watering practices (limited overhead) and decreasing humidity are both important during production. Kalmowitz also suggests developing a thorough sanitation program. Together, these cultural practices can help prevent the development and spread of Botrytis.
Kalmowitz recommends cleaning up where pots have gotten tipped over or leaves have broken off. Removing old plant material is a good practice because Botrytis doesn’t only attack the live plant, but it can establish on plant waste at the end of a bench, underneath a bench or in a garbage can, she says. If you remove it, you are prohibiting the spores from hopping back into clean, non-infected plants.
A preventative chemical application to protect from Botrytis infections is a wise move. Botrytis can be a problem throughout the production of many species. A good rotational spray program contains potentially three different products, each from a different fungicide chemical group as defined with a FRAC code (Fungicide Resistance Action Committee). During young plant production, the product rotation should include pesticides offering varying residual protection that either kill upon local contact, or act systemically, upon distribution throughout the treated plant.
Continue this management rotation during finishing and shipping, when Botrytis is also a concern. At that time, consider the placement of those products in rotation with one additional thought: undesirable residue remaining on the plant.
“Some of the chemicals in the marketplace right now are very good and they should be used, but some may leave visible residue,” she adds. An appearance of residue may not be attractive to consumers at retail. “In that case, there should be an application of that product early in the spray program, not when you’re about two weeks away from shipping,” she says.
Kalmowitz’s recommended Botrytis chemical rotation in early plant production:
- Pageant® Intrinsic® brand fungicide (Group 7 + 11) at sticking
- Followed by Daconil (Group M5), Decree (Group 17) or Medallion (Group 12)
- Followed by Pageant Intrinsic brand fungicide
Always read and follow label directions.
©2016 BASF Corporation. Pageant and Intrinsic are registered trademarks of BASF Corp. Daconil and Medallion are registered trademarks of Syngenta Corp., and Decree is a registered trademark of Arysta LifeScience of North America, LLC.
For more tips about disease prevention and BASF products, visit betterplants.basf.us
Photo courtesy of BASF