This 2003 report found the most common cause of decay was identified as bacterial soft rot (Erwinia carotivora). Calcium fertiliser levels and tuber calcium content was explored in this report alongside the importance of sourcing clean certified seed.

This 2003 paper by SA Research &Development Institute delves into the postharvest washing of potatoes to find where bacterial soft rot originates and where it develops. The report suggests some ways in which soft rot causing bacteria can be controlled in this process.