Grain size hectolitre weight and screenings determination – from DC93

Within the manual Protocols for experimental plot sampling, handling and processing of cereals in field experiments(external link) by G.J. Rebetzke (, A. van Herwaarden, B. Biddulph, C. Moeller, R. Richards, A. Rattey and K. Chenu.

Good estimates of grain size are important in calculating grain number per m2 and grain number per spike.


  1. For 100 grain weight, count out 100 whole grains on a flat surface (eg table-top), weigh grain and return to sample
  2. For hectolitre weight, take a vial of 50mL volume, fill level and weigh. Calculate hectolitre weight as: 100*[mass grain screened (in kg)/volume grain screened (in l)]
  3. Pour the grain from the hectolitre sample over a certified 2mm grain sieve and shake 40 times. Calculate screenings <2mm as: (weight <2mm/total grain weight) x 100 (Fig. 26).
  4. Occasionally you may want to keep some grains for analysis of protein concentration. These can be stored in dry, cool conditions until ready for analysis.
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Figure 26. Grain sample (a) before shaking over a 2mm grain sieve; (b) Separation after sieving into pinched/shrivelled grain less than 2mm in width (left) and full grain greater than 2mm in width (right).

Other resources

Appendix 1.(external link) Text description of phenological scale, Zadoks decimal code (DC).
Appendix 2.(external link) Picture description of phenological scale, Zadoks decimal code (DC).
Zadoks JC, Chang TT, Konzak CF (1974) A decimal code for the growth stages of cereals. Weed Research 14(6),415-421. doi: 10.1111/j.1365-3180.1974.tb01084.x

Notes and troubleshooting tips


Download complete manual: Protocols for cereal field experiments_Nov2012.pdf

Health, safety & hazardous waste disposal considerations


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