The Role of Calcium and Cell Permeability in the Disease Blossom‐end Rot of Tomatoes

Research was carried out concerning the cell‐physiological backgrounds of the disease blossom‐end rot of tomatoes, which, like bitter pit of apple and lipburn of lettuce, is a Ca‐deficiency disease. In our experiments tomatoes with the least amounts of Ca were attacked by the disease. We estimated the ion permeability of tissues with different Ca levels. Permeability was found to increase with decreasing Ca contents in the tissue. The increase accelerated with the beginning of the disease. The artificial rise in the permeability caused by ether and decenylsuccinic acid resulted in an increased occurrence of the disease. It is probable that the Ca‐deficiency causes the necrosis of the tissue in blossomend rot and that the shortage of calcium among others affects the disorganization of membranes and organells in the cell.