IMPORTANCE AND CAUSES OF STRESS CRACKS IN KERNELS OF MAIZE

Samples of the maize harvest in 1988 for cornflakes-production were taken before and after the harvest as well as after drying and tested for damage caused by stress cracks. Thereby, unfavourable conditions like high temperatures and/or very low relative humidity (< 50%) during the drying process were detected as the main reason for the formation of stress cracks. Crop moisture and the final moisture content also had an influence. Any differences between the varieties could not be detected. In practice a complete avoidance of stress cracks is not possible since stress cracks already appear when maize kernels are being treated very carefully (seed production). A substantial decrease of damage can be achieved by drying the cobs carefully and by the dryeration-method (MUHLBAUER und KUPPINGER 1975).