Spring frost protection in orchards by under canopy sprinkler irrigation. (L'Accademia per il post Covid-19.)

Spring frost events are predicted to increase due to climate change. Yield losses caused by late radiative frosts can be highly remarkable in many fruit species, mostly stone fruits, grapes and kiwi, and active protection means are part of a general need for adaptation in orchard management. The principle of using over canopy and under canopy irrigation is based on the property of water that, when freezing, releases heat. Technical and management tools able to magnify such effect have been developed and here described for under canopy application, when the icing of water sprinkled to orchard grass allows adequate increase of the air temperature at canopy level.