The primary function of potassium in plant growth is to regulate various physiological processes, including water regulation, enzyme activation, and photosynthesis. Potassium helps maintain turgor pressure in plant cells, which is crucial for structural integrity and growth. It also plays a vital role in carbohydrate metabolism and protein synthesis. Adequate potassium levels enhance plants' resilience to environmental stresses, such as drought and disease, ultimately contributing to higher yields in agriculture.