Author
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NELSON, STUART |
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Submitted to: Seed Technology Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/26/2002 Publication Date: 9/27/2002 Citation: NELSON, S.O. DIMENSIONAL AND DENSITY DATA RELATIONSHIPS FOR SEEDS OF AGRICULTRUAL CROPS. SEED TECHNOLOGY. 2002. V. 24(1). P. 76-88. Interpretive Summary: The densities (mass or weight per unit volume) of kernels of grain and seeds of other agricultural crops are important for many reasons. They are useful in determining the porosity of grain, which is important in grain drying and aeration. Kernel and seed densities are related to test weights of grain, which are bulk densities determined under prescribed conditions and are important in determining quality of grain lots and selling price. Kernel density is related to milling quality in wheat and can serve as an indicator for seed quality in many crops. Kernel and seed dimensions and densities were determined for twenty different kinds of grain and seed of agricultural crops. Three mutually perpendicular dimensions of the kernels and seeds were measured along with their weights and volumes. The new data have been analyzed and assembled for reference. In addition, a new technique was found for estimating the volume of the seeds of other seed lots of the same kind. Volume coefficients were developed for each of the different kinds of seed, which when multiplied by the product of the three mutually perpendicular dimensions of a seed will provide an accurate estimate of the seed volume. Then by weighing the seed, the seed density can also be estimated by dividing the seed weight by the calculated volume. The new dimensional and density data and techniques for estimating seed volume and density offer a convenient alternative to the tedious measurements previously required to determine kernel and seed densities. These data and techniques will be useful to seed scientist in their research and to engineers designing equipment for grain drying and other grain and seed processing applications. Technical Abstract: Dimensions of seeds of twenty different agricultural crops were determined by caliper measurements. Individual seed weights were obtained, and mean seed volumes were determined by air-comparison pycnometer measurements for use in determining seed densities. Seed densities ranged from 1.002 for safflower to 1.460 for milled rice. Test weight (bulk density) measurements were also taken and moisture contents were determined by standard tests. Collectively, these data supplement the limited seed density data currently available in the literature for reference. The product of three orthogonal dimensions (length, width and thickness) was calculated for each kind of seed. A volume coefficient was determined as the ratio of the measured mean volume to the orthogonal-dimension product. The volume coefficients, which ranged from 0.222 for oil-type sunflower seeds to 0.588 for sweetclover seeds, are useful in estimating seed volume from seed dimensional data. With use of the appropriate volume coefficient, seed density can be estimated for a particular kind of seed from seed weight and dimensions. |
