Mechanical damage to soybean seed during processing

Abstract The effects of seed cleaning and handling on soybean seed germination and physical integrity were determined with changing seed moisture content (m.c.). In addition, storage behavior of seed and loss of storability caused by damage resulting from free-fall from different heights were determined. Six lots of the variety “MACS-13” at three different m.c.'s were passed through a vertical bucket elevator, cleaner with grader, and gravity separator and evaluated for mechanical damage, germination, and vigor index. The storage behavior of the lots, at different stages of processing, was studied by performing an accelerated aging test. The effect of free-fall on quality of the seed was studied by dropping six seed lots from four different heights on to cement and galvanized iron floors. The vertical bucket elevator significantly decreased germination and increased splits and seed coat damage. The seed lots at 12% m.c. (dry basis), suffered less loss in seed quality than the lots at 10% or 11% m.c. The storage quality of seed, as predicted by the accelerated aging test, at 12% m.c. was also better than the lots at 10% or 11% m.c. A free-fall of soybean seed from different heights on to the cement floor resulted in greater loss in quality than when dropped on to the galvanized iron floor.