What are some signs of nutrient deficiency in plants?

Nutrient deficiency in plants often manifests through various physical symptoms, and yellowing leaves along with leaf drop are classic indicators of this condition. When plants lack essential nutrients such as nitrogen, magnesium, or iron, chlorosis, or yellowing of the leaves, typically occurs, particularly in the older leaves. This is because the plant reallocates nutrients to the newer growth, causing older leaves to lose their green color. Furthermore, if the nutrient deficiency persists, it can lead to leaf drop, as the plant sheds leaves to conserve resources.

In contrast, the other choices present symptoms that are not directly linked to nutrient deficiencies; for instance, brown tips on leaves accompanied by rapid growth may indicate over-fertilization or environmental stress rather than a lack of nutrients. Increased pest activity and a strong odor could suggest pest infestations or other issues rather than deficiencies, while flowers blooming earlier than usual might be tied to environmental factors like temperature and light conditions instead of nutrient availability.