Common name: Potassium(P) deficiency


Potassium deficiency is a widespread deficiency of plants and can cause severe yield losses if not treated rapidly. Potassium is one of the most used elements of the annual fertilizer plan, along with phosphorous and nitrogen (N, P, K), because it contributes to the robustness and quality of the plant and controls many procedures related to water and nutrients movement in plant tissues. Sandy soils with low pH and insufficient aeration can lead to deficiency. Potassium uptake is also affected by soil temperature and moisture and plays a vital role in fruit quality.


Leaves: Interveinal chlorosis mainly of older leaves. Leaves may curl downward, and a necrotic area appears at the leaf tips and margins, which then progresses toward the leaf base. Younger leaves are smaller, with a pale green colour. Sometimes, leaves roll along edges, have a bronze colour, and drop prematurely, which may lead to severe defoliation and stunted appearance of the tree.

Stem: Stunted appearance. Thin canopy and necrotic branches.

Fruits: Reduced fruit size and production. Sometimes, fruits become soft with thin peel and drop prematurely. K deficiency can also cause lower acid concentration of fruits.

Hosts: apples, citrus, tomato, potato, peach, barley, corn, olive tree, etc


University of Minnesota: Potassium for crop production

Panagopoulos, C. (2007) Diseases of fruits trees and vineyards. 4th Edition

Zekri, M., and Obreza, T. (2019) POTASSIUM (K) FOR CITRUS TREES. Department of Soil and Water Sciences, UF/IFAS

University of Minnesota extension: Potassium for crop production.

Panagopoulos, C. (2007) Diseases of fruit trees and vineyard. 4th Edition. Athens

Zekri, M., and Obreza, M. (2019) POTASSIUM (K) FOR CITRUS TREES. Department of Soil and Water Sciences, UF/IFAS