Grading of Seeds

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Grading of Seeds

 

in a seeder, the division of seeds, according to size, into groups corresponding to the sizes of the compartments in the seeding mechanism.

Seed is sorted so that seeds can be sown one by one or in sets of a predetermined number, decreasing waste of the sowing material and cutting down sharply on the labor needed to tend the plantings. Corn, sugar beet, cotton, and other crop seeds are graded after preliminary machine-cleaning. Agricultural grading machines or seed cleaners with the necessary gratings are used for the process.

Large-scale seed grading was first used in the USSR with corn after construction in 1956– of grading plants, which supply seeds (packed according to grade in sacks) to kolkhozes and sovkhozes. Corn kernels fall into six grades, according to thickness and width (see Table 1).

Table 1
Grade numberSize of seeds (mm)
 WidthThickness
1…………9.0–10.5 (11.0)3.75–5.5
2…………8.0–9.03.75–5.25
3…………7.0–8.03.75–5.0
4…………6.5–7.03.75–4.75
5…………8.0–10.5 (11.0)5.25–7.0
6…………6.5–8.04.75–7.0

Sugar beet seeds are graded (using screens with round open-ings) into two groups (diameter, 4.5–5.5 and 3.5–4.5 mm). Cot-ton seeds are graded in cotton ginning plants, according towidth, thickness, and length, into two groups, after first remov-ing the linters from their surface.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.