THE IRON-MANGANESE RATIO IN RELATION TO THE RESPIRATORY CO2 AND DEFICIENCY-TOXICITY SYMPTOMS IN SOYBEANS
Open Access
- 1 April 1942
- journal article
- research article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 17 (2) , 317-320
- https://doi.org/10.1104/pp.17.2.317
Abstract
Soybean plants were grown in culture solns. containing different absolute amts. and relative concs. of Fe to Mn for a 10-day period. Normal plants free from pathological symptoms were produced only when the ratio of Fe to Mn in the substrate had values between 1.5 and 2.5. The production of CO2 by the roots of these plants was measured for a 24-hour interval at the end of 10 days of minor-element treatment. The max. yield of respiratory C02 per 10 grams of green tissue occurred within the range of normal plant growth. Low respiratory rates in the root are associated with an unfavorable balance between Fe and Mn in the substrate and in the plant. The pathological symptoms which developed at low values of the Fe/Mn ratio are those considered usually to be those of Fe deficiency or Mn toxicity. These 2 diseases are here considered to be identical. Likewise at high values of the Fe/Mn ratio the necrotic condition which develops is similar to that which has been either associated with Fe toxicity or Mn deficiency. Excellent plants can be grown with both remarkably low concs. and relatively high conc. of both Fe and Mn provided that a favorable balance between these heavy metals exists in the substrate and in the plant. The ratio of concs., rather than the absolute amt. of these trace elements, has a profound influence upon the metabolism of the plant in general as shown in the respiration of the roots and the vigor of the plant as a whole.This publication has 1 reference indexed in Scilit:
- SIGNIFICANT RÔLES OF TRACE ELEMENTS IN THE NUTRITION OF PLANTSPlant Physiology, 1941