Gravity Table Sorting of Commodity Corn

摘要

Gravity tables are used in the seed industry to sort seed corn and other seeds for upgrading seed quality. Tests were conducted to determine if commodity corn could be sorted for quality by gravity table. Three commodity corn lots were sorted using an Oliver model 50 gravity table. Samples were drawn at three times from the feed and from four discharge fractions: heavy, heavy/medium, medium, and light. All samples were tested for test weight, breakage susceptibility, moisture, Chowdhury damage, starch, protein, oil, and density. Three measurements of physical properties (test weight, breakage susceptibility, and Chowdhury damage) showed many significant differences among fractions at a = 0.05. Quality of the heavy fractions was highest, and decreased through the lighter fractions with the light fractions having the poorest quality. There were few differences among sampling times. Chemical properties (protein, oil, starch) and moisture showed little difference among fractions at a = 0.05. Removal of the light fraction from commodity corn lots can result in lower BCFM levels in this corn at final destinations, overseas or domestic.