Fertilizer by crop stage: a grower’s guide

A crop does not need the same fertilizer all season. Young roots, leafy growth, flowering and fruit sizing each draw on different nutrients. Matching the product to the stage is how growers get more from every application. This guide explains the logic, using the Green Magic range that Loka International distributes as examples.

How do you read an NPK label?

The three numbers on a compound fertilizer are the percentages of nitrogen (N), phosphorus (shown as P₂O₅) and potassium (shown as K₂O), in that order. Multi Power 20-20-20 is balanced. Multi Power 10-40-10 is high in phosphorus. A high first number means a nitrogen-led product.

• Nitrogen (N): leaves and shoots, green growth.
• Phosphorus (P): roots, energy, flowering and fruit set.
• Potassium (K): fruit size, colour, sugar and quality.

Stage 1: rooting and establishment

After planting or transplanting, the aim is a strong root system. Root stimulants and humic products help here. Examples: Magic Roots (phosphorus, potassium and micronutrients) and Magic Mix (potassium humate with micronutrients, which improves soil structure). See the full agricultural inputs range.

Stage 2: vegetative growth

During leaf and shoot growth the crop needs nitrogen, plus micronutrients such as iron, zinc and manganese to avoid deficiency. Examples: Action Power N, a balanced NPK suspension for the vegetative stage, and chelated micronutrients such as Balance Iron and Balance Zinc.

Stage 3: flowering and fruit set

Phosphorus, calcium and boron support flowering and fruit set. Examples: Action Power P, a high-phosphorus suspension for flowering and rooting, Bloomix, and calcium-boron products such as Calborat.

Stage 4: fruit sizing and quality

As fruit swells, potassium becomes the main need for size, colour and sugar. Example: Action Power K, a high-potassium suspension for the sizing stage.

What is a suspension fertilizer?

A suspension carries a higher load of nutrients in a liquid than a clear solution can hold. The Action Power line and Green Mix Plus are suspensions. Shake the container well before use.

Use with care

• Rates depend on the crop, soil, water and stage. Follow the product label, and an agronomist’s advice where possible.
• Crop-protection products must be used according to their registered label.
• The Green Magic range is manufactured by Green Magic and carries its trade marks. Loka International is the distributor.

For availability and pack sizes, contact us.