Salwinder Singh was arrested from Ranipur Chhota village here for killing his 16-year-old Sulakhan Singh on the night of May 5.
Sulakhan was missing from his house after a wrangle with his father, police said.
Salwinder, without informing the police, tried to cremate his son immediately after the body was recovered from the fields, police said.
On a tip-off, police reached the cremation ground and remains of the body were taken into possession and sent to the FSL for examination.