Dragging Dew

There is one job on the course that is not well known but is done with the same regularity as mowing the greens and raking the bunkers.  That job is dragging dew.  We don not want to discount the benefits dragging dew has to the early morning golfer, but the main reason for doing the practice is the agronomic benefits of it.

Diseases occur on turfgrass when three conditions exist.  There needs to be a pathogen present, a susceptible host for the pathogen to attach to, then environmental conditions for that pathogen to survive on the host.  Any two of these being present will not result in an outbreak of disease.  All three need to be present for disease symptoms to appear on turfgrass. The diagram on the right is illustrating this.

An environment suitable for a pathogen to colonize a plant includes moisture or the duration of leaf wetness.  The longer there is moisture on the leaf blade from dew, irrigation or rain, the chances for disease outbreaks increase.  By dragging the dew off of the leaf blade it allows the turf canopy to dry more rapidly that it otherwise would have been able to do if the dew was left on the plant, thus decreasing the duration of leaf wetness and decreasing the chances that a pathogen has to survive.  This practice is not a method of disease control, rather a method of disease suppression.