Why do plants need Pottasium?

plants need potassium to make flowers and fruits

Potassium regulates the opening and closing of the stomata. Since stomata are important in water regulation, potassium reduces water loss from the leaves and increases drought tolerance.

Potassium serves as an activator of enzymes used in photosynthesis and respiration.

Potassium is used to build cellulose and aids in photosynthesis by the formation of a chlorophyll precursor. Potassium deficiency may result in higher risk of pathogens, wilting, chlorosis, brown spotting, and higher chances of damage from frost and heat.