Deficiency Symptoms
Upper leaves remains small in size, becomes curved. Interveinal portion turns yellow with necrotic spots on veins. Fruit size get reduced, seed setting is less in fruits. Khaira disease in paddy is caused due to zinc deficiency.
Conditions Affecting Zn Availability
- Soil low in Zn (depending on parent material)
- High pH, low organic matter and Heavy limed soil
- Clay soil with high Mg levels
- Excessive sulphate and phosphate content in the soil solution will result in immobilization of zinc
- High available P can accentuate Zn deficiencies as well as high N fertilization and very high
potassium levels may also induce Zn deficiency - Under anaerobic conditions, zinc can be precipitated into the barely soluble sulphide form which is largely unavailable to plants
- Soils high in N & K inputs
- Cold wet conditions