Effect of Transpiration Upon the Absorption and Distribution of Mineral Salts in Plants

Distribution of Nitrogenous and Carbohydrate Fractions and Other Substances in Exposed and Covered Pineapple Sister Shoots

“…Variations in the sucrose content of different leaf and stem sections are discussed. 8. Calcium was found in greater quantities in the leaf and stem sections of exposed than of covered shoots, indicating that absorption was greater by the former than by the latter shoots.…”

Transpiration and the Absorption of Mineral Salts

“…The work of HASSELBRING (7), KIESSELBACH (9), MUENSCHER (12), MENDI-OLA (10) and others indicates that different rates of transpiration are without effect upon the absorption of mineral salts. Investigations conducted by HAss and REED (6), HITCHCOCK and ZIMMERMAN (8), and FRFELAND (3,4) support the contention that transpiration is a factor which affects the absorption and translocation of mineral salts.…”

Effect of Transpiration Upon the Absorption of Mineral Salts

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ONE DOES not need to delve far into the voluminous literature pertaining to mineral absorption by plants to be convinced that there are many factors which may, either directly or indirectly, affect this process. Therefore, it seems only reasonable that to measure the effects of transpiration upon mineral absorption it will be necessary to keep all of these other influential factors as nearly constant as possible.For example, in an earlier paper by the writer on this subject (Freeland, 1936) the significance of the data was somewhat obscured by inequalities in growth and dry weight of the plants. Furthermore, the importance of such factors upon mineral absorption as synthesis of foods, assimilation, and shoot-root growth is well illustrated by the work of Gustafson (1934), Muenscher (1922), Mendiola (1922, and others.

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“…From several sources, but more recently in a paper by Hoagland and Broyer (1936), it is clear that aeration, respiration, temperature, initial salts in the root tissues and culture medium, and available carbohydrates in the plant are factors concerned in the absorption of minerals. The size of these cases, light and temperature conditions, as well as the methods of controlling humidity, were essentially the same as those previously described (Freeland, 1936).The plants used were grown from seeds which were suspended upon cheesecloth over tap water that was continually aerated. Therefore, it seems only reasonable that to measure the effects of transpiration upon mineral absorption it will be necessary to keep all of these other influential factors as nearly constant as possible.…”

“…Furthermore, the importance of such factors upon mineral absorption as synthesis of foods, assimilation, and shoot-root growth is well illustrated by the work of Gustafson (1934), Muenscher (1922), Mendiola (1922, and others. The volume and concentration of the culture solutions were kept approximately constant by frequent additions of distilled water.For the determination of the amount of salts absorbed, the same analytical methods as those of previous experiments (Freeland, 1936) were used for Ca, P, and K. Aliquot parts of the culture solution were analyzed at the beginning and end of the experiment. The same criticism may be made of most of the data that have been presented to date for the purpose of showing that transpiration either does or does not affect the rate of absorption of minerals.…”