Magnesium deficiency

Magnesium deficiency is a physiological disorder in plants that occurs when the plant cannot obtain enough magnesium from the soil, which is an essential component of the chlorophyll molecule. Without this element, the plant's ability to photosynthesize is severely impaired, leading to stunted growth and reduced metabolic function.

This condition affects a vast range of crops, with corn being particularly susceptible during periods of rapid growth. Other crops like tomatoes, potatoes, and various fruit trees are also prone to these symptoms, especially when grown in high-yield intensive agricultural systems.

The primary symptom is interveinal chlorosis, which starts on the older, lower leaves. The tissue between the veins turns yellow, orange, or sometimes reddish-purple, while the veins themselves remain green. In corn, this manifests as characteristic pale-yellow striping between the veins, eventually leading to necrosis of the leaf edges in severe cases.

Development is facilitated by soil conditions such as high acidity (low pH), high leaching potential in sandy soils, and high concentrations of competing cations, particularly potassium or ammonium. High levels of potassium fertilization often induce a secondary magnesium deficiency because the two elements compete for uptake by root hairs.

The economic impact involves significant yield losses and lower quality of harvested products due to reduced sugar synthesis and photosynthetic capacity. Protective measures include soil testing, applying magnesium-rich amendments like dolomitic lime for long-term correction, and using foliar sprays for rapid recovery during the growing season.

• Conduct regular soil testing for nutrient balance.
• Apply lime to acidic soils to increase magnesium availability.
• Avoid excessive potassium fertilization without magnesium balance.
• Use foliar magnesium sulfate application for immediate symptom relief.