• Because of recent weather patterns, damping off in soybeans may be more of a problem than usual this year.
If you are among those fortunate enough to get some soybeans planted last week or earlier, one of your next concerns may become soybean damping off.
Our weather patterns suggest soils will stay wet for at least five days, maybe more. Because of this, we may be facing more damping off issues than we would like to see.
Damping off (the death or injury of young seedlings or failure to emerge) is caused by a number of different fungal and fungus-like pathogens, namely Phytophthora, Pythium, Rhizoctonia and Fusarium spp. Each type of pathogen may prefer a different soil temperature range, but they all like it wet.
If you find you are having issues with damping off this season, not much can be done for this year’s crop apart from some dry weather.
However, take note of your bean variety’s resistance to Phytophthora root rot (if any), and any seed treatments your beans received. This can help you determine which group of fungi (or fungus-like organism) caused your problem so you can be ready for it in the future.
There is genetic resistance available to Phytophthora spp., but not any of the other pathogens that may cause damping off. Also, seed treatments that contain metalaxyl or mefanoxam are only effective against Phytophthora and Pythium spp. while other products are effective only against true fungi like Rhizoctonia and Fusarium spp.
If your seed was treated with a combination product that includes both of these types of materials, it can be effective against all of these pathogens.
Here is a list prepared by Laura Sweets at the University of Missouri that can help you determine what kind of product your seed may have been treated with: http://extension.missouri.edu/seregion/Agronomy/Soybean_Seed_Treatment_Fungicides.htm.