Maturity machine harvest samples – 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.

Careful, organised harvesting of each plot will provide a good estimate of plot yield, and possibly seed for the next season.


  1. As soon as possible after the latest maturing plots are harvest ripe, trim the ends of plots and measure the harvested plot length. Record area of any quadrats or other sections of plot removed with earlier sampling. Avoid where possible the harvest of edge rows
  2. Before harvest, confirm labelled bags and/or labels/tags are in correct plot order.
  3. Calibrate the wind speed in the small plot header on a border plot for both the rainfed and irrigated trials so that as much of the grain is retained but without retaining too much trash. Droughted plots commonly produce a high proportion of small or shrivelled grain. Avoid losing too much of this material through too high a blower speed.
  4. Weigh the harvested grain and subsample 250 g for later moisture determination. The remained of the harvested grain can be disposed of unless needed for sowing seed. Note if keeping seed for sowing, to be careful in avoiding contamination from preceding plots.
  5. Dry the 250 g sub-samples at 35C if you wish to use for sowing seed (otherwise 70C) and weigh. Avoid use of this seed for 100-grain weight, hectolitre weight or screenings. Use instead the harvest index processed grain.

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Figure 27. Preparing to harvest the next plot in a field experiment.

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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