Zinc deficiency in coconut palms
Zinc(Zn) is an essential element that takes part in enzyme activation, protein synthesis, and hormone regulation in plants. Due to the deficiency of Zinc(Zn) leaflets become chlorotic, narrow, and shortened in length.
Symptoms of Zinc Deficiency in Coconut
- Formation of Shortened leaves ( leaf size is reduced to 50%) are major symptom of Zn deficiency in coconut palms.
- The deformed leaves will have a "rosette" appearance.
- Characteristic pale yellow discoloration appears between the veins of younger leaves.
- A compact appearance of the crown is noticed due to a reduction in space between leaflets.
- In acute deficiency, flowering is delayed.
- Zinc deficiency will also lead to button shedding.
- It occurs mostly in saline soils.
- In advanced condition, older leaves may droop and dry out.
- Reduction in yield. A smaller number and size of coconuts are occurred.
- Delayed or irregular flowering patterns are observed in palms with Zn deficiency.
Causes of Zinc deficiency
- In sandy or alkaline soils with high pH levels Zinc content is very low.
- Excess phosphorus fertilizers can bind zinc in the soil, making it unavailable to plants.
- Zinc may be leached off from the root zone due to heavy rainfall.
Inadequate soil organic matter hinders the availability of zinc
How to correct the Zn deficiency in Coconut palms?
- Soil application of Zinc sulfate (ZnSO₄·7H₂O) at the rate of Soil application of ZnSO4 @ 10 Kg/acre per year. Mix it with soil or water for better absorption.
- Foliar application of 0.5% Zinc sulfate solution (5 g per liter of water) with 1 g of lime to prevent leaf burn. Spray this solution on the younger leaves.
- The overall availability of micronutrients, including zinc can be ensured by improving the organic matter status of the soil.
- Biofertilizers with zinc-solubilizing bacteria may be added to the soil to enhance the availability of zinc.
- Avoid waterlogged conditions, as it will reduce the uptake of zinc.
- Maintain soil pH in the range of 5.5 to 6.5 for optimal zinc availability. Apply sulfur or gypsum to lower pH in alkaline soils if needed.
- Avoid application of excess phosphorus or other fertilizers that interfere with zinc uptake.
- Grow legumes or other plants that improve soil health and nutrient cycling.
- Periodic testing helps monitor zinc levels and guide fertilizer applications.
Zinc (Zn) deficiency in coconut palms can significantly affect the growth, productivity, and overall health of the coconut palms. Timely detection and correction of Zn deficiency can improve the health, yield, and quality of nuts.
