Tensile Characteristics of Sorghum Spikelet and Grains

In order to solve problem of unclean threshing of sorghum during mechanical harvest，tensile mechanical properties of sorghum spikelet and grain were studied.In this experiment，three varieties of Liaoza-37，Jinza-34 and Xingxiangliang-2 were selected as research objects.Different harvest periods and growth position were taken as experimental factors，and tensile fracture force was taken as experimental indexes to study influence of various factors on tensile fracture force during grain and spikelet of sorghum.Results showed that variety，harvest time and growth position had significant influence on tensile fracture force of sorghum spikelet and grain，and main test factor affecting tensile fracture force was growth position.Tensile fracture force was related to growth potential of sorghum itself.The force required for sorghum spikelet fracture increased from top to bottom with growth potential，and variation range was from 2.479 N to 9.627 N.Moreover，variation trend of sorghum grain tensile fracture force with growth position was basically similar to that of spikelet，and variation range was from 2.386 N to 8.314 N.Among three varieties，Xingxiangliang-2 has the strongest bearing capacity and the greatest tensile fracture force.Mechanical properties of sorghum at different harvest times were different.In general，sorghum should be harvested at dough stage.This study provides a theoretical reference for research and optimization of sorghum harvesting equipment and timely harvest.