Agronomy Degree Practice Exam

The chemical symbol for the element that significantly improves stem strength in plants is potassium, represented by the symbol K. Potassium plays a vital role in various physiological processes within plants, including water regulation, enzyme activation, and photosynthesis. One of its key functions is strengthening the cell walls, which contributes to enhanced firmness and stability in stems, ultimately helping the plant to resist lodging and other mechanical stresses.

While other elements listed contribute to plant health in various ways, they do not specifically focus on stem strength. For example, molybdenum (Mo) is critical for nitrogen fixation and enzyme function in plants; iron (Fe) is essential for chlorophyll synthesis and preventing chlorosis; and zinc (Zn) is important for enzyme activation and the development of reproductive tissues. However, potassium is uniquely known for its role in promoting strong stem development, making it the correct choice.