On the basis of an integrated wheel-type tractor (traction class 3.0), there was created the new combined machine and tractor unit carried out a continuous flat cutting of the sugar beet tops with a front mounted sugar beet tops cutting machine. To carry out this field experimental studies, a program and methodology was developed based on measurements of the remains of the tops on the heads of root crops after passing through the aggregate at a given rate of translational motion, the height of the installation of its rotary cutting mechanism above the level of the soil surface and the frequency of its rotation. The results of the study were statistically processed on a personal computer using regression and correlation analysis methods. Based on the developed methodology of the full-factor experiment, empirical mathematical models were constructed in the form of regression equations for the process of cutting the tops of sugar beet. According to the results of these calculations, it was found that the speed of the forward movement of the sugar beet tops cutting aggregate exerts the greatest influence on the mass of the remains of the tops on the spherical surfaces of the root heads, after a continuous main cut. In a lesser extent, this process is influenced by the rotational speed of the rotor of the sugar beet tops cutting machine and the height of the rotor installation above the soil surface level by means of two pneumatic copying wheels. According to the results of experimental studies, it has been established that the rational design and technological parameters of the process for harvesting sugar beet tops by a front mounted sugar beet tops harvesting machine with a rotary cutting apparatus is its rotation frequency equal to 960 rpm, the speed of the aggregate should not exceed 2.0 m.s-1, and the height of the rotor installation should be as low as possible, not less than 0.02 m.