Magnesium Deficiency in Coconut

Magnesium deficiency in coconut palms

Though Magnesium is a secondary plant nutrient, it is very much essential for important plant metabolic activities.  Since  Magnesium is a component of chlorophyll, its role in photosynthesis is vital. It is also involved in various enzymatic processes. Magnesium deficiency in coconut palms would adversely affect tree growth. Magnesium deficiency symptoms differ from those of K deficiency. In Pottassium-deficient leaves discoloration starts as orange to bronze, whereas Mg- Mg-deficient leaves have distinctly green leaf centers and bright lemon yellow to orange margins are noticed.

Major symptoms of Magnesium deficiency in Coconut palms

• Deficiency symptoms appear on the oldest leaves of palms as broad chlorotic (yellow) bands along the margins with the central portion of the leaves remaining distinctly green.
• Yellowing starts at the leaf tip and spreads to the base.
• The Older leaves become bronzed and give a dry appearance.
• The Leaflets show necrosis and turn to reddish brown with translucent spots can be noticed.
• Leaflet tips turn necrotic, in severe cases.
• Interveinal chlorosis takes place due to the inability of the plant to produce chlorophyll without sufficient magnesium.
• Reduced growth and reduction  in yield
• Stunted growth, reduced fruit production, and smaller coconuts.

Causes of Magnesium deficiency

• Low availability of magnesium to the plant.
• In areas with heavy rainfall or excess irrigation, magnesium can leach out of the soil, leading to deficiency.
• Coconut palms require potassium, but excessive potassium can interfere with magnesium uptake, leading to a deficiency.
• If magnesium is not supplied along with major nutrients, coconut palms may not receive sufficient amounts of this essential nutrient.

How magnesium deficiency can be corrected?

1. Based on periodical soil testing, apply magnesium-containing fertilizers, such as magnesium sulfate (Epsom salt), dolomitic lime, or other magnesium-rich fertilizers.
2.  In general soil application of 1-2 kg MgSO₄  /palm /year or  Root feeding of 200 ml of 0.2% MgSO4 twice a year will take care of the deficiency.
3. If the soil is acidic, lime application can help raise the pH and improve the availability of magnesium. Since Dolomite contains both calcium and magnesium, the application of dolomite will take care of the Magesium requirement.
4. Magnesium deficiency can be corrected through foliar sprays of magnesium sulfate.
5. A balanced supply of essential nutrients, including potassium, nitrogen, and phosphorus, along with magnesium is ideal.
6. Over-reliance on potassium fertilizers should be avoided, as it could aggravate magnesium deficiency.

As an essential element, Magnesium deficiency could lead to poor growth and yield. By improving soil conditions, appropriate fertilization, and ensuring a balanced nutrient, magnesium deficiency in coconut palms can be effectively corrected.