Wilted PDF Download

The term freezing to death is applied to a very specific set of phenomena in plants. With all plant tissues, when a certain temperature is reached very shortly after thawing, it will be found that the tissue has taken on a brown, water-soaked appearance, and evaporation from that tissue is much more rapid than from living tissue. In the experiments described in this paper, the killing temperature of plant tissue that kills at relatively high temperature has been reduced whenever the sap density of the tissue has been increased. Results of many investigations have shown that during freezing (which may or may not result in freezing to death), ice forms in the tissue, generally not in the cells but in the intercellular spaces, the water moving out of the cells to form crystals in these spaces. The most commonly accepted theory is that killing from cold results from the withdrawal of water from the protoplasm. The amount of water loss necessary to result in death varies with the different plants and different tissues. This paper studies the effects of cold weather on plant tissue, specifically concerning tissue death and the preventative measures that have been taken in the past and could be taken in the future. It is focused on Missouri apples, peaches, plums, and cherries.