Potassium affects bruising, increased levels of potassium can reduce the level of tuber bruising. This trial from England shows the relationship between potassium content and the incidence of tuber bruising over a range of varieties.
High levels of calcium in the tuber also reduce bruising risks at harvest and subsequent transportation. Varieties vary in their calcium uptake, however, using calcium nitrate rather than ammonium nitrate minimizes 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 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. This trial shows how boron influences the calcium content of tubers and so also the incidence of tuber bruising.