| Popis: |
AN adequate supply of highly purified water is an essential requirement for the study of plant nutrition problems, particularly those relating to mineral deficiencies, when experiments are carried out on a large scale. Liebig, Vanselow and Chapman1 in California found that tap water purified by the synthetic resin ion-exchange principle was satisfactory for maintaining healthy growth in citrus and sweet lemon without any toxic effects. They did not, however, report any experiments using demineralized water in deficiency cultures, although they published analytical results indicating that considerable removal of certain of the major and trace elements was effected by the treatment. Schroeder, Davis and Schafer2 have recently published a note in which they conclude that demineralized tap water is unsuitable as a substitute for distilled water for boron-deficiency cultures. Using the latter, symptoms of this deficiency developed in canning beet in five weeks, whereas, in parallel cultures with the demineralized water, no symptoms were observed. |
