Therefore, the development and research of technologies and technical means for assessing root crops and potatoes for resistance to mechanical damage during harvesting represents a scientific problem, the solution of which will contribute to the innovative development of the domestic market of agricultural products, the stable position of Russia in the foreign market, and will ensure the transition to highly productive production of agricultural products. As a result, the following will occur:  
* An increase in labor productivity;
* Improvement in the quality of products;
* Reducing the cost of production and providing the population of the Russian Federation with valuable food products. At the moment, a machine for harvesting potatoes and root crops has already been invented [6], for which the design of the functioning elements are the basic schemes of modern harvesting machines, with a separation device from soil and plant impurities made in the form of a rod elevator (Figure 1), which is installed at an angle of 10 degrees to the horizon to achieve vertical lifting of the separated products to a height of 0.26 m to improve cleaning. The working speed of the web of the bar elevator is 2.5 m/s, which leads, when interacting with various types of shakers, to a forceful effect on the processed pile of root crops to potatoes and therefore to damage to the products. Thus, the assessment of the resistance of tubers to mechanical damage during harvesting using industrial harvesting machines cannot be used directly at the initial stages of breeding new varieties. This is only possible at the last stage of the breeding process--before the transfer of the variety to state tests. In light of consistent introduction of mechanization technologies of cultivation, harvesting and after-harvest processing of potato, and due to the period of tuber storage before their sale or planting, additional demands are placed on the inheritable properties (inheritable traits) of potato plants. The steadily increasing amount of mechanical action on tubers during cultivation, harvesting and placement in storage define the need for the selection of potato varieties for increased resistance to mechanical stress. Mechanical damage is traditionally classified as external (surface) and internal damage. External damage includes types of damage that may be detected by visual inspection: jacket scarring, scratches, cracks, dents, tears, cuts, crushed tubers, etc. Internal damage types include darkening of flesh and internal cracks [PERSON], [PERSON], [PERSON] [7; 8; 9]. Currently, the intrinsic resistance of tubers to mechanical damage is assessed during regular harvesting with conventional harvesting machines [10; 11; 12; 13]. This technique, however, cannot be used at early breeding stages of a new variety; it is applicable to the final stage of the selective process only--before a variety is submitted for state tests [14; 15; 16; 17]. Figure 1: Testing stand of RIAE Prague for samples mechanical loading examination (mechanical loading motion simulator). The results and conclusions of analytical studies of potato tuber damage by the work elements of KKU-2 type harvesters make it possible to specify and adjust the design of modern potato harvesters using experimental studies of potato tuber damageability. The Research Institute of Potato Breeding (Korenevo Settlement, Luybertsy District, Moscow Region) conducted the most comprehensive, theoretically substantiated and accurate studies of potato tuber damage at specific working elements of KKU-2 Druzhba harvester in cooperation with GSP KTV (Ryazan). The studies were conducted in the Ryazan and the Moscow Regions. During the numerous experiments, tuber damage was determined by sequentially taking samples during harvester stops at each work element. The amount and structure of tuber damage were determined both at the input of each work element and after the tubers left it. Tubers were selected in small batches of 10 pieces at every stop.