Soft rots are a range of warm weather bacterial diseases, usually Erwinia carotovora subsp. Atroseptica, that enter the tubers through mechanical damage and rots the tubers in storage. Therefore, correct balanced nutrition of the crop prior to harvest, particularly calcium and boron nutrition can have positive effects against soft rots.

Calcium helps strengthening the tuber cell wall hence reduce the severity of Erwinia soft rot in storage. High levels in the tuber also reduce bruising risks at harvest and subsequent transportation. Even though varieties varies in their level of uptake, however, using calcium nitrate rather than ammonium nitrate maximizes uptake, reduces the risk of damage allowing ingress of disease, because the use of calcium nitrate rather than ammonium nitrate resulted in higher levels of calcium in tubers over a range of different potato varieties.

Boron is also an important element present in the cell wall, because it acts as cement between pectin, providing cohesive strength for cell tissues, hence affects tuber storage quality characteristics and calcium absorption. Therefore supplies are important to ensure a balanced nutrition.

Other crop management practices to help reduce potato soft rots includes: harvesting early, thereby minimising late disease ingress or tuber deterioration, taking care during harvest and grading to reduce physical damage and bruising, disinfecting seed storage areas to reduce disease carry over, harvesting in good conditions to avoid physical damage and disease infestation, using in-store treatments (e.g. fungicides) to reduce tuber disease build-up and controlling temperatures and humidity in storage.

Courtesy of: https://www.yaracanada.ca/crop-nutrition/potato/reducing-incidence-of-soft-rots/