FFA Floriculture Practice Test

What color indicates a nitrogen deficiency in green plants?

1. Green

2. Yellow

3. Brown

4. Red

The correct answer is: Yellow

A nitrogen deficiency in green plants typically results in yellowing of the leaves, particularly in older leaves. Nitrogen is an essential nutrient that plays a crucial role in the production of chlorophyll, which is vital for photosynthesis. When plants do not receive enough nitrogen, they cannot produce sufficient chlorophyll, leading to chlorosis, where the leaves lose their green color and turn yellow. This is often most visibly seen in the lower or older leaves, as plants may redirect available nitrogen to newer growth. Therefore, yellow is the color that indicates a nitrogen deficiency, highlighting the importance of nitrogen in maintaining healthy, green foliage in plants.