Specialty tractor provided with a diesel engine coupled with a powertrain including a clutch and a manual shift transmission having an output shaft (6-b) that is designed to transmits power to the wheels of the tractor, the diesel engine is also coupled with a PTO box having a PTO shaft for powering towable implements, characterized by comprising an electric generator receiving torque directly from the diesel engine and providing electric power to an energy accumulator such as a battery or a supercapacitor; power electronics is designed to draw up electrical power from the energy accumulator to supply an electric motor whose output shaft (11-a) may be connected /disconnected though a power transmission to said output shaft (6-b); an electronic unit for controlling power electronics and said power transmission, the electronic unit being configured to perform at least: a first operating mode wherein the clutch is opened and the manual transmission does not receive any torque from the diesel engine; the electric motor supplied by the energy of the accumulator transmits torque to the wheels of the tractor that moves on the ground with a speed lower than a speed limit; the diesel engine is controlled so that it has a set Rpm that produces a desired angular speed of the PTO shaft making the angular speed of the PTO shaft independent from the speed of the tractor on the ground; and a second operating mode wherein the clutch is closed and the manual transmission receives torque from the diesel engine so that the engine-torque is transmitted to the wheels of the tractor that moves at a speed higher than the speed limit; during the second operating mode the electric motor is unpowered. characterized by comprising an electric generator receiving torque directly from the diesel engine and providing electric power to an energy accumulator such as a battery or a supercapacitor; power electronics is designed to draw up electrical power from the energy accumulator to supply an electric motor whose output shaft (11-a) may be connected /disconnected though a power transmission to said output shaft (6-b); an electronic unit for controlling power electronics and said power transmission, the electronic unit being configured to perform at least: a first operating mode wherein the clutch is opened and the manual transmission does not receive any torque from the diesel engine; the electric motor supplied by the energy of the accumulator transmits torque to the wheels of the tractor that moves on the ground with a speed lower than a speed limit; the diesel engine is controlled so that it has a set Rpm that produces a desired angular speed of the PTO shaft making the angular speed of the PTO shaft independent from the speed of the tractor on the ground; and a second operating mode wherein the clutch is closed and the manual transmission receives torque from the diesel engine so that the engine-torque is transmitted to the wheels of the tractor that moves at a speed higher than the speed limit; during the second operating mode the electric motor is unpowered. a first operating mode wherein the clutch is opened and the manual transmission does not receive any torque from the diesel engine; the electric motor supplied by the energy of the accumulator transmits torque to the wheels of the tractor that moves on the ground with a speed lower than a speed limit; the diesel engine is controlled so that it has a set Rpm that produces a desired angular speed of the PTO shaft making the angular speed of the PTO shaft independent from the speed of the tractor on the ground; and a second operating mode wherein the clutch is closed and the manual transmission receives torque from the diesel engine so that the engine-torque is transmitted to the wheels of the tractor that moves at a speed higher than the speed limit; during the second operating mode the electric motor is unpowered.