Properties of Ice Nuclei Associated with Peach Trees

Abstract

No relationship was observed between the population of ice nucleation active (INA) bacteria and the temperature at which ice formed in peach [ Prunus persica (L.) Batsch] shoots. The ice nucleation temperature remained stable throughout the year, even during periods when INA bacteria were not detected. An intrinsic ice nucleating substance seemed to be responsible for initiating ice formation and limited supercooling to about —2°C. The ice nucleating agent seemed to be a constitutive component of mature wood and was stable under a range of chemical treatments. Ice nucleation was influenced by sample mass, temperature, and length of exposure. The freezing behavior of peach shoots was best described using a stochastic model of ice nucleation.