Role of Potassium in Potato Production

Potassium plays a key role in water relations and good overall plant health. Potato plants absorb large quantities of potassium throughout the growing season.

Potassium in potato and frost

Potassium has an important role in the control of the plant water status and ionic concentrations inside plant tissues, including stomata. As a result of the improved cell strength that potassium provides in potatoes, stress such as frost can be better tolerated, as study in India shows.

Potassium in potato yield

Potassium also influences the transport of nutrients and the movement of sucrose from the leaf to the tuber. Potassium in potato is critical for high yields. In five trials across three years on K-rich volcanic soils (Ecuador), 107 lb K2O/ac increased average yields by 4.7 t/ac.

Potassium form and potato yield

It is important that potassium availability is not limiting. Trials in Bulgaria show that potassium nitrate in potatoes is a particularly effective formulation, providing readily soluble and quickly absorbed potassium and nitrate nitrogen in comparison with other potassium forms.

In South African trials, use of potassium nitrate in potatoes in conjunction with calcium nitrate, ensures fast uptake of all three important elements enhancing yield over and above other products.

Potassium form and potato bruising

Potash reduces the level of tuber bruising. Sulfate of potash (SOP) in comparison, can lead to greater bruising than muriate of potash (MOP) when tubers with a high dry matter content are produced, as shown in UK trials.

Potassium form and dry matter

Sulfate of potash can provide higher dry matter content than muriate of potash, as shown in studies in Denmark. Therefore sulfate of potash is frequently the preferred form for processing potatoes.

General guidelines for application of potassium in potato

It is important that potassium availability is not limiting. Trials show that potassium nitrate is a particularly effective formulation, providing readily soluble and quickly absorbed potassium and nitrate-nitrogen in comparison with other potassium forms. This makes potassium nitrate particularly effective in sidedressing applications during the potato bulking stage. Sulfate of potash is also an acceptable form for delivering potassium. Muriate of potash is less desirable as excess chlorides can reduce quality. 

Potassium at potato growth stages
Planting Early growth and dry matter
Post planting Growth and dry matter

Role of Nutrients

Read about the role of other nutrients in potato production:

Nitrogen

Phosphorus

Potassium

Calcium

Magnesium

Sulfur

Boron

Copper

Iron

Manganese

Molybdenum

Zinc

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jimmy ridgway
Jimmy Ridgway
Regional Sales Manager