Role of nutrients by apple growth stage

Bud Burst - Start of Flowering

apple bud

  • 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

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