Surface and Irrigation Types Have a Big Impact on Water Splash in Nurseries, Choose Wisely!

In nurseries, plant pathogens can spread via water splash from the ground to container plants growing on benches. We used suspensions of fluorescent microspheres the size of Phytophthora spp. propagules to compare the vertical water splash resulting from three irrigation methods on five surface types. Using hand watering, the number of water droplets that splattered to a maximum height of 3’ was significantly higher from concrete than from dry bare soil, weed barrier fabric, gravel, or a mud puddle. Hand watering and impact spray generated limited water splash at heights between 2.5 and 3’. However, spray sprinklers resulted in no water splash above 2.5’. Our results indicate that spread of plant pathogens from the nursery surface to plants placed on raised benches is possible, but unlikely to reach levels needed for successful infection, and that the risk for such transmission can be further reduced by choosing adequate surface types, watering systems and bench heights.