Role of Potassium in Cotton Production

Potassium is integrally involved in metabolism and plant/water relations, it is an enzyme activator but it is not a constituent of any known plant components. It has been proven to be involved in over 60 enzymatic reactions, and in many processes in the plant such as photosynthesis, respiration, carbohydrate metabolism, translocation and protein synthesis.

Potassium balances charges of anions and influences their uptake and transport. Another important function is the maintenance of osmotic potential and water uptake. These two functions of K are manifest in its role in stomatal opening when stomatal conductance and turgor are coupled. Another major role of K is in photosynthesis by directly increasing leaf growth and leaf area index, and therefore, CO2 assimilation.

Potassium increases the outward translocation of photosynthate from the leaf. In cotton, K plays a particularly important role in fiber development. Potassium affects the fiber quality, the micronaire, length and strength, it reduces the incidence and severity of wilt diseases and increases water use efficiency. The bolls are major sinks for K, and the uptake may reach 3,2 kg/ha a day during the intense part of boll development. About 70% of total K uptake occurs after the first bloom.