Correct nutrition of the crop prior to harvest can minimise the risk of bruising occurring. Potassium, calcium and boron all have effects that reduce tuber bruising.

Potassium

Potassium affects bruising, increased levels of potassium can reduce the level of tuber bruising.

Calcium

High levels of calcium in the tuber reduce bruising risks at harvest and subsequent transportation. Varieties vary in their calcium uptake, however, using calcium nitrate rather than ammonium nitrate minimises bruising damage and in some varieties, damage can be halved.

This trial from the USA shows that the use of calcium nitrate rather than ammonium nitrate resulted in higher levels of calcium in tubers over a range of different varieties.

Boron

Boron helps stabilize calcium in the cell walls and also affects calcium absorption, so supplies are important to ensure a balanced nutrition and to maximizes the benefits of applied calcium.

Other crop management practices influencing potato tuber bruising

• Selecting the right variety to meet dry matter production needs 
• Harvesting in good conditions to avoid physical damage 
• Taking care during harvest and grading to reduce physical damage and bruising 
• Scheduling irrigation to maximize quality characteristics 
• Controlling temperatures and humidity in storage