EN
To meet the construction requirements for sugar beet harvesting and processing machines the knowledge of sugar beet mechanical properties is essential. For that reason stress relaxation of sugar beet root tissue was investigated on the Instron 1253 strength tester. Standard 3-parameter rheological model was applied to quantitative description of uniaxial compression phenomena. As a result of experiment an equation of stress relaxation curve was obtained and technical parameters, such as elastic relaxation modulus, modulus of elasticity, viscosity coefficient and time-constant, were calculated. For methodical reasons the effect loading rate and sample fixing on mechanical parameters were also determinated. Statistical analysis showed close agreement between experimental and theoretical results proved by low error of fitting the curves and high correlation coefficient.