What is a symptom of magnesium deficiency in plants?

A symptom of magnesium deficiency in plants is that older leaves turn yellow between the veins, a condition known as interveinal chlorosis. This occurs because magnesium is a crucial element that plays a key role in photosynthesis and the production of chlorophyll. When there is insufficient magnesium, the plant cannot produce enough chlorophyll, leading to yellowing of the leaf tissue while the veins remain green. This yellowing typically starts in the older leaves first, as magnesium is a mobile nutrient, allowing the plant to transport magnesium from older leaves to newer growth when it is deficient.

In contrast, the other symptoms listed, such as the tips of leaves turning brown, wilted new growth, or flowers developing incorrectly, are associated with different deficiencies or issues that don't specifically relate to a lack of magnesium. These symptoms might indicate other nutrient deficiencies or physiological problems in the plant, such as potassium deficiency or environmental stress factors. Understanding the specific signs of nutrient deficiencies helps in identifying the precise needs of plants for better care and management.