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ARS Home » Plains Area » Manhattan, Kansas » Center for Grain and Animal Health Research » Stored Product Insect and Engineering Research » Research » Publications at this Location » Publication #425427
Research Project: Advancing Technologies for Grain Trait Measurement and Storage Preservation

Location: Stored Product Insect and Engineering Research

Title: VOLUME AND DENSITY MEASUREMENTS OF SINGLE SORGHUM GRAINS VERSUS SAMPLE TEST WEIGHT

Author
item Brabec, Daniel
item Grothe, Sophia
item NEILSEN, MITCH - Kansas State University
item ZHAO, KAI - Kansas State University
item Bean, Scott
item Baker, Neil
item Scully, Erin
item Yeater, Kathleen

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Seed density and test weight are two foundational properties used to determine sorghum quality. While higher seed density is important for breeding programs, test weight is an important metric to determine the quality and value of grain after harvest, with higher test weights having higher grades and quality. The two metrics can be correlated with each other and breeders need rapid methods to assess grain quality. To rapidly measure seed density, we developed a single seed rotating imaging system capable of generating 3-D models to determine individual seed volumes and densities of sorghum grain. From the individual seed volumes, overall sample densities could be computed, which were significantly correlated with bulk test weights. Thus, this 3-D imaging system represents a rapid method for predicting test weight and assessing seed quality. In addition, this system could be used for separating high- and low-quality seeds based on densities.

Technical Abstract: Sorghum production is on the rise in the United States and breeders need rapid methods to assess grain quality. One of the most important metrics of grain quality is test weight, with low test weight sorghum having poor quality and marketability. In this study, we developed a revolving 3-D imaging instrument capable of measuring the volume of single sorghum seeds and also density, when single seed weights were included. Using a diverse set of sorghum samples with varying test weights, we assessed whether composite density calculated from single seeds was correlated with test weight and bulk density. For these experiments, the bulk test weights were measured for a set of uncleaned sorghum samples and ranged from 51 to 59 lbs/bu. When dockage was removed with an aspirator, test weight values of the samples improved to 55 to 61 lbs/bu. We then separated the sorghum seeds into four size categories (small, medium, large, and extra-large) and determined single seed volumes and density using our 3-D instrument. A single seed was placed on a revolving pedestal and imaged every 10 degrees. The imaging software collected 36 images per seed during the 360 degrees of rotation. Then, those 2-D images were processed to form a 3-D model of the seed and individual seed volumes were computed. The volumes of the individual sorghum seeds were ~9, ~14, ~21, and ~28 mm3 for the small, medium, large, and extra-large sizes, respectively. Each single grain was weighed and the individual seed densities were calculated. Composite grain density values from single seed measurements ranged from 1.22 mg/mm3 to 1.33 mg/mm3 and were linearly correlated with the clean-sample test weight values (R2 = 0.71).