Efforts to keep in business what was once Poland’s largest tractor manufacturer have foundered as a result of Covid-related disruption and other factors that led a Warsaw-based regional commercial court to declare the business bankrupt and appoint a receiver.

At its height in the 1980s, Ursus produced as many as 60,000 tractors a year but sales declined in the face of competition from western manufacturers producing more modern products and sales dropped to fewer than…