Relationship of Electrolytic Conductance to Cold Injury and Acclimation in Fruit Trees1,2

Abstract

Electrolytic conductance was measured from acclimated and nonacclimated seedlings of apple, pear and citrus which were frozen and unfrozen. A close correlation between electrolytic conductance and survival was shown. A comparison was made between conductance and injury of apple and pear trees in the natural freeze of 1968-69 in Washington. Procedures are outlined for using conductance as a measure of cold tolerance among cultivars or treatments within the same cultivar. The use of T₁₀ and T₉₀, which describes the transition range of injury, is outlined and described. Procedures are also outlined for following acclimation or deacclimation through the year and for determining freeze-injury from natural freezes.