Effects of Mechanical Threshing Damage on Wheat Storage Quality Traits

Mechanical threshing damage to wheat grains is inevitable in harvesting, threshing damaged wheat grains are seriously susceptible to mold colonies. Wheat grains harvested by tangential flow and axial flow mechanical threshing patterns were used as test samples and harvested manually wheat grains were used as control group samples for testing storage quality traits. Moisture content of the wheat samples were adjusted to 18% (wet basis) before storage, then wheat samples were stored in an artificial climate box at temperature of 30 °C and humidity of 80% RH. Wheat storage quality traits were tested during storage. The testing results of storage wheat showed that the number of mold colonies and the fatty acids value of wheat grains harvested by tangential flow threshing increased faster than that by axial flow threshing, the dry basis 1000-grain weight, seed vigor and germinating traits of wheat grains harvested by tangential flow threshing decreased faster than that by axial flow threshing during storage. After the wheat storage, there was a significant difference in the number of mold colonies of wheat, wheat seed vigor, dry basis 1000-grain weight between the tangential flow threshing method and the axial flow threshing method (p<0.05). The germination potential and germination rate were significantly negative correlation with number of mold colonies of wheat. The number of aberrations seedling and the number of mold colonies in seedling root were significantly positive correlation with the number of mold colonies of wheat. The storage quality traits of wheat grains harvested by axial flow mechanical threshing pattern were better than that by tangential flow mechanical threshing pattern. The axial flow threshing pattern should be preferred for mechanical harvesting wheat grains in term of the storage safety and storage quality of wheat grains.