P&PDL Picture of the Week for
January 3, 2005

Hang those hoses!

Karen Rane, Plant Disease Diagnostician, Department of Botany & Plant Pathology, Purdue University

Many root rot pathogens, such as Pythium, Fusarium and Rhizoctonia, are commonly found in soil, drainage water and plant debris under greenhouse benches.  When these microorganisms are introduced to soilless potting mixes used in commercial greenhouse production, they can cause significant disease problems.  Keeping these detrimental microorganisms away from the roots of greenhouse plants will help minimize root rot problems and reduce the need for fungicide soil drenches. Nozzles dropped on the floor below the greenhouse bench (Photo 1) will pick up soil and water droplets which can contain plant pathogenic fungi.  When the crop is watered using the contaminated nozzle, the microorganisms will be washed into the pots on the greenhouse bench.  Hanging hoses above the greenhouse floor (Photo 2) is one of the easiest ways to help keep root rot pathogens in their place –  and reduce root rot damage in greenhouse crops.

For more greenhouse sanitation tips, check out the following publications:

“Sanitation Strategies for Greenhouse Growers”  by  Thomas Dudek, Ottawa County Extension, Michigan State University

“Disinfecting the Greenhouse” by Tina Smith, Extension Educator, University of Massachusetts

Click on image to enlarge

Photo 1 By resting this hose nozzle on the dirt floor, it is becoming potentially contaminated with root rot microorganisms.  (Also note: weeds under greenhouse benches can harbor diseases and insect pests).

Photo 2 Hanging the nozzle helps to keep it free of root rot pathogens found in soil or water on the greenhouse floor.  Concrete floors and excellent weed control also help reduce the incidence of greenhouse diseases and insect pests.

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service