Potassium Deficiency

Class: Nutritional Disorders
Common Name: Potassium (K) deficiency
Symptoms:

Drying of tips and along leaf edges (oldest leaves affected first)

Interveinal chlorosis along leaf margins

Ragged appearance (dried leaf tissue falls from leaflet edges)

Delayed maturity and poor yields

Uneven ripening of fruits

In Short:

Potassium is one of the three primary macronutrients required in high amounts by all plants. Potassium is what the “K” stands for in “N. P. K.” fertilizers. K+ is the most abundant cation found in plants cells.

Potassium plays many important regulatory roles in plant development processes; it affects osmotic regulation and is involved in the opening and closing of stomata. Therefore, it affects photosynthesis and water regime in plants.

When potassium uptake is inadequate, the stomata responds slowly. This results in less water circulation in plants, making them more susceptible to drought and temperature changes.

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Control Measures

Heavy crop production rapidly depletes the soil of potassium. This can be remedied by applying agricultural fertilizers that contain potassium.

Usually, potassium fertilizers are applied during the planting stage. Although in some cases, as when dealing with sandy soil or when soil contain high amounts of potassium-fixing minerals, several applications of potassium fertilizers are needed.

Potassium chloride (KCl) or muriate of potash (MOP) are widely used potassium fertilizers.

Potassium nitrate (KNO3) is known to be used in foliar sprays or fertigation due to its high water solubility characteristics.

Caution and careful notice should be taken when using any plant protection products (insecticides, fungicides, and herbicides). It is the grower’s sole responsibility to keep track of the legal uses and permissions with respect to the laws in their country and destination markets. Always read the instructions written on labels, and in a case of contradiction, work in accordance to the product label. Keep in mind that information written on the label usually applies to local markets. Pest control products intended for organic farming are generally considered to be less effective in comparison to conventional products. When dealing with organic, biologic, and to some extent a small number of conventional chemical products, a complete eradication of a pest or disease will often require several iterations of a specific treatment or combination of treatments.