Potassium Deficiency (plants) - Potassium Deficiency and Plant Disease

Potassium Deficiency and Plant Disease

For many species, potassium-deficient plants are more susceptible to frost damage and certain diseases than plants with adequate potassium levels. Increased disease resistance associated with adequate potassium levels indicates that potassium has roles in providing disease resistance, and increasing the potassium levels of deficient plants have been shown to decrease the intensity of many diseases. However, increasing potassium concentration above the optimal level does not provide greater disease resistance. In agriculture, some cultivars are more efficient at K uptake due to genetic variations, and often these plants have increased disease resistance. The mechanisms involved with increased host resistance and potassium include a decreased cell permeability and decreased susceptibility to tissue penetration. Silica, which is accumulated in greater quantities when adequate potassium is present, is incorporated into cell walls, strengthening the epidermal layer which functions as a physical barrier to pathogens. Potassium has also been implicated to have a role in the proper thickening of cell walls.