The frosty nights "burnt" many blossoms

Due to greater vinyards and orchards the farmer used big candles in those 2 frosty nights or sprayed the plants with water to become them iced. This techniques is unknown to me and as far I learned is the defrosting a severe moment and demands warm weather otherwise the blossoms get destroyed due to the energy which is draw when ice melts again.
A good view gives a recent article in alocal news Frostkerzen. The iced versions "irrigation of the vinyards" is published in Meteo Schweiz   Frostbewässerung. The extra pictures are taken from those links to give you an impression here.