Rubidium for Plants: A Substitute for Potassium
Rubidium (Rb)
Despite the chemical similarity between rubidium and potassium, the absorption and transport of rubidium in plants, as established, differs from that of potassium.
Rubidium is most often accumulated in the root system.
In fungi, the concentration of rubidium varies from 3 to 150 mg/kg. The maximum rubidium content in fungi reaches 160 mg/kg. For some bacteria, the accumulation of rubidium and other monovalent cations in vacuoles is known.
In case of excess rubidium in the soil, the leaves of plants acquire a dark green color, wither, and the number of shoots significantly increases, while their sizes are small.
• meadow clover Trifolium pratense L., Fabaceae (herb, content – 44 mg/kg);
• alfalfa Medicago sativa L., Fabaceae (herb, content – 93 mg/kg);
• timothy Phleum pratense L., Poaceae (herb, content – 130 mg/kg);
• red fescue Festuca rubra L., Poaceae (herb, content – 135 mg/kg);
• chlorella Chlorella Beij., Chlorellaceae (division green algae Chlorophyta);
• garden radish Raphanus sativus L., Brassicaceae (root vegetables).