Liquid Zinc Sulphate: The Hidden Key to Plant Growth

Why is zinc such a critical micronutrient?

Liquid zinc sulphate is used to correct zinc insufficiency · the most frequently encountered micronutrient deficiency in agricultural production · quickly and effectively. Zinc is indispensable for the synthesis of growth hormones (especially auxin), enzyme activation, protein formation and chlorophyll production. Without zinc, plant growth slows, leaf area shrinks and yield falls dramatically.

Under what conditions does zinc deficiency appear?

Zinc deficiency becomes pronounced particularly in these situations:

• High pH soils (pH > 7): zinc becomes insoluble in an alkaline environment
• Excess phosphorus application: phosphorus blocks zinc uptake
• Calcareous and sandy soils: low zinc-binding capacity
• Cold soil conditions: early-season deficiency is common in spring

What are the symptoms of zinc deficiency?

Zinc deficiency can be recognised visually:

• Small, rosette-shaped leaves (internodes shorten)
• Yellowing on young leaves, particularly between the veins
• Small fruit and misshapen fruit
• Late flowering and poor fruit set

Why choose liquid zinc sulphate?

The most widely used zinc forms are zinc sulphate and zinc EDTA chelate. Each has its own field of use:

• Zinc sulphate: cost effective, dissolves quickly in water, effective between pH 5 and 7
• Zinc EDTA chelate: effective across a wide pH range (4–9), high bioavailability; preferred on alkaline soils

The liquid form dissolves faster than the solid and can be applied both foliarly and through drip irrigation.

Timing and rate

Foliar application

Usually applied at 0.2–0.5% concentration (2–5 ml/L) every 10–14 days. It should be intensified during flowering and shoot development.

Soil / drip irrigation application

A soil application can be made at the start of the season or when symptoms appear. On alkaline soils the chelated form should be preferred.

Combined applications

Zinc can be combined with boron, magnesium and iron. Applying it at the same time as calcium and phosphorus should be avoided.

Frequently asked questions

For which crops is zinc sulphate most critical?

Zinc deficiency is most widespread and most damaging in maize, rice, wheat, tomato, pepper, apple, peach and citrus.

Can zinc and iron be applied at the same time?

Yes, in most cases they can be combined. At high concentrations, however, a small-scale test is recommended before mixing them in the same tank.

How do I choose between zinc sulphate and zinc EDTA?

If soil pH is below 7, zinc sulphate is sufficient; above that, zinc EDTA chelate is far more effective. The chelated form stays soluble and available at high pH.

What happens if too much zinc is applied?

Excess zinc can be phytotoxic · browning of the leaves and stalled growth are seen. The recommended rate should not be exceeded.