Sunday, 31 December 2017

Raindrops splash pathogens onto crops



Two mechanisms of pathogen dispersal have been discovered. The first is a vortex ring mechanism, where one ring of pathogenic particles propagates and radially disperses after a drop impacts a plant surface. In the other, the pathogens are dispersed by an elastic collision mechanism. Jung describes this in terms of billiard balls: "You have billiard balls forming a triangle shape so if you hit the one ball in the front the other balls will be kicked out."

The identification of these mechanisms was not without its challenges. Pathogens are microscopic, around 10 micrometers, and extremely fast moving with speeds of 1 meter per second, so deducing mechanisms based on their liberation patterns was no simple task. The research team employed strong laser lights and high-speed cameras to capture and track the pathogens.

At the root of this problem is its oppositional nature: Rain is a natural process supplying thousands of gallons of fresh water to crops every year, but at the same time dispersing pathogens and damaging agricultural yields. This research provides insights into possible agricultural solutions for this issue.

Source: American Physical Society's Division of Fluid Dynamics

Posted by Dr. Tim Sandle

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