Pythium root rot found in local tobacco float beds

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The unseasonably warm temperatures prevalent over recent weeks have pushed things in the plant world, including disease. 


Last week, we confirmed Pythium root rot on some fairly young tobacco seedlings. 

Pyth-ium root rot is common in tobacco float beds, but we usually do not see much of this disease until ad-April; however, warm weather has created favorable conditions ahead of schedule.

After trays have been seeded and floated, the best control option for Pythium root rot is Terramaster EC. The earliest that this fungicide should be applied to float beds is when plant roots begin to enter the water (normally three or so weeks after seeding).

Terramaster will cause plant injury, and newly-emerged tobacco seedlings are particularly sensitive to the fungicide.

When Pythium attacks plants before the recommended window for Terramaster, growers do not have a good option for disease control.  The best approach in these cases would be to check trays regularly for evidence of the emergence of roots from the tray bottoms, and make an application of Terramaster EC at 1 fluid ounce per 100 gallons of float water as soon as roots can be seen. 

A follow up treatment at the same rate 2-3 weeks after the first application would be advisable – particularly if temperatures stay warm. Proactive management practices will give growers the best shot at avoiding losses.

Pythium can be hard to diagnose on young tobacco seedlings, so please send samples into the Carroll County Extension Office if you suspect this disease. The samples will be shipped to the diagnostic lab at the University of Kentucky for confirmation. 

For more information, stop by the Extension Office to pick up the UK fact sheet titled, “Pythium Root Rot in Tobacco Float Systems.” It provides more details on diagnosing and managing Pythium root rot.

Source:  Dr. Kenny Seebold, UK Extension Plant Pathologist

Dates of interest

April 24:RiverView Farmers Market meeting, 6:30 p.m., Carroll County Extension Office.

April 30:Good Agricultural Practices (GAP) Training, 9:30 a.m. or 6 p.m., Carroll County Extension Office.

May 3:Pesticide Container Recycle Day, 9 a.m. to noon, Carroll County Extension Office.

June 1: Deadline for FSA Sign Ups (DCP and ACRE Programs).

June 1:Final Cut-Off Date for NRCS Sign Ups (EQIP, Hoop Houses, and On-Farm Energy Initiatives).


Christin Herbst is the Carroll County Extension agent for agriculture and natural resources. Call her at (502) 732-7030 or send e-mail to Christin.Herbst@uky.edu.