Role of nutrients by apple growth stage
Bud Burst - Start of Flowering
- Nitrogen, Potassium and Magnesium – promote strong early growth of new plant tissues and maximum tree productivity
- Phosphorus – maximize root development and flower cluster formation
- Calcium – boost root and leaf growth and high yields
- Boron – maximize pollination and strong flower development
- Manganese – to maximize tissue growth
- Zinc – to optimize bud burst and early leaf development
Fruit Set - Fruitlet
- Nitrogen – in reduced amounts to maintain fruit fill
- Potassium – minimize fruit disorders
- Phosphorus – fruit set and development
- Calcium – maintain good fruit quality and minimize fruit disorders
- Magnesium – for reduced fruit drop
- Boron – improve fruit set
Fruit Fill - Maturity
- Nitrogen – in reduced amounts to maintain fruit fill and high sugars (excess can lead to rots and quality deterioration)
- Potassium – maximize fruit weight, TSS levels in the fruit and minimize disorders and sunscald (but at levels that don’t compete with calcium)
- Calcium – maintain good fruit firmness and storage quality
- Manganese – alongside Phosphorus will promote fruit coloration
Post Harvest
- Nitrogen and Potassium – boost reserves for next season’s early growth
- Phosphorus – maximize bud development and early rooting and new tissue growth in the following spring
- Calcium – maintain high levels in the tree
- Magnesium, Boron, and Zinc – replenish reserves and strengthen new buds
