What is a common symptom of nitrogen deficiency in corn?

Yellowing of lower leaves is a classic symptom of nitrogen deficiency in corn. Nitrogen is a vital nutrient that plays a key role in chlorophyll synthesis, which is crucial for photosynthesis. When there is insufficient nitrogen in the plant, the older, lower leaves often exhibit a yellowing effect first, as the plant reallocates nitrogen to the newer, actively growing tissues. This yellowing, also known as chlorosis, occurs because as nitrogen becomes limited, the plant begins to break down its own tissues to redistribute the nutrient where it is most needed, typically in the upper leaves and growing points.

In contrast, wilting of upper leaves may indicate water stress rather than a nutrient deficiency, stunted growth can result from various factors, including a lack of multiple nutrients or poor growing conditions, and a dark green color typically suggests an excess of nutrients, particularly nitrogen, rather than a deficiency. Recognizing the specific symptoms of nitrogen deficiency is crucial for making informed fertilization decisions and ensuring optimal crop health and productivity.