How to use benchmarks to assess cereal growth

Measurements are vital to good management and for learning. As well as assessing weeds, pests and diseases, managers must assess the cereal plant itself. Crop progress, structure and final performance can then be compared with benchmarks (where available) or new targets.

Benchmarks are simply a standard by which something can be measured or judged.

In this context, these numerical (quantitative) reference points allow comparison of a crop’s performance to be made.

Wheat and barley trials (conducted on variety standards) have established benchmarks for a wide range of traits – from typical emergence duration to average grain weight.

They are not definitive, as benchmarks vary in the extent to which they are affected by genetics (heritability). For example, other varieties and sowing dates may reach key stages earlier or later than the benchmark date.

Benchmarks are a starting point in your journey to measure and understand crop development.

Benchmarks with high heritability are strongly influenced by choice of variety, whereas benchmarks with low heritability are principally controlled by husbandry choices.

In our guidance, the heritability of each benchmark is indicated as ‘High’, ‘Medium’ or ‘Low’ and the other management factors with a significant effect are listed.

Note: Some benchmark data for modern varieties can be found within the AHDB Recommended Lists datasets.

Each benchmark is based on observations of a high-yielding feed wheat variety with a slow rate of development at UK sites through several seasons. Unless otherwise stated, crops were sown in early October at 375 seeds/m² and grown with ample nutrition, complete crop protection and without lodging. The first edition of the AHDB Wheat growth guide was published in 1997. The latest edition was published in 2018. During the revision, each benchmark was checked for accuracy and updated (where necessary).

Each benchmark represents a median (middle) value derived from measurements made on the two-row winter barley variety 'Pearl' during three harvest years (2002–04). Trials were sown between 15 September and 10 October at six trial sites across the UK. Full crop protection and lodging control were applied to minimise potential crop losses. Fertiliser use was for feed quality grain (rather than for malting). Where known, differences for six-row and hybrid winter barley and spring barley are highlighted.

The first edition of the AHDB Barley growth guide was published in 2006. The latest edition was published in 2018. During the revision, each benchmark was checked for accuracy and updated (where necessary).