THE CHOICE OF THE FREEZING EXPOSURE IN DETERMINING FROST RESISTANCE OF HAZEL AND APPLE

Abstract

Death of parenchymal cells of xylema shoots after freezing through the annual increment takes place after reaching the tissue temperature of the critical level, the less the tissue viability is lost in such situation and depending on the exposition intensity, the less resistant plots of the annual layer are damage first of all. It is quite decent to expose the object to critical temperature within one minute in order to cause significant subfreezing and death of cells.