Role of sodium and chloride in plant culture
Function: Sodium is not an essential element for plants but can be used in small quantities, like micronutrients, to aid in metabolism and chlorophyll synthesis. In some plants, it can be used as a partial replacement for potassium and aids in the opening and closing of stomata, which helps regulate internal water balance. Chloride is needed in small quantities and aids in plant metabolism, photosynthesis, osmosis (movement of water in and out of plant cells), and ionic balance within the cell.
Deficiency: Sodium “deficiency” does not appear to exhibit any symptoms since it is not an essential element. Chloride deficiency can occur if there is consistently less than 2 ppm chloride in the growing medium and the symptoms appear as chlorotic blotches with necrotic spots located between the veins or on the margins of the younger leaves. In advanced cases, chloride deficiency could cause plant wilting. Both deficiencies rarely occur since most water sources provide them and fertilizers often have them as impurities.
Toxicity: Sodium toxicity appears as necrosis or scorching of the leaf tips and margins, like micronutrient toxicities. Chloride toxicity starts as premature yellowing of leaves and then leads to marginal or tip necrosis of older leaves and also bronzing. Geraniums, lettuce and poinsettias are sensitive to chloride toxicity while carnations, penstemons, tomatoes and verbenas are less sensitive.
Click here to read more at pthorticulture.com
Source: Newsletter of Premier Tech Horticulture
