RL harvest results deliver early indication of variety performance

Farmers can get the latest Recommended Lists (RL) variety data via AHDB’s harvest results. Jason Pole, who manages technical communications, outlines how the cereals and oilseeds data is released.

Between harvest and the release of the next RL (2024/25, due 27 November 2023), the three RL crop committees and RL board will consider all data, follow an agreed process, and decide on the fate of each variety in trial.

However, there is demand for variety data before the release of the RL, as most winter crops are drilled well before the new RL becomes available.

The good news is that farmers can access results shortly after each major crop trial is cut, via the harvest results web page and eshots.

RL major crops*

• Winter wheat
• Spring wheat
• Winter barley
• Spring barley
• Winter oats
• Spring oats
• Winter oilseed rape

Prior to release, all crop data is validated by the RL team to eliminate results that do not meet the RL’s strict quality standards. If this step was not followed, it could result in the publication of misleading information.

Typically, the first results (winter barley) are available from mid- to late-July.

The harvest results web page already features information on the trial sites (includes location, soil types and sowing dates) and sowing lists (cites all varieties in trial) for harvest 2023.

For each crop, two harvest results tables are published and updated during the harvest period:

1. Yield tables provide fungicide treated and untreated yield results
2. Full harvest results tables provide yield and non-yield results, such as quality, agronomic and disease data

The RL team also issues regular commentary to put the results in context. This covers, for example, information on the season, unusual results and associated uncertainty.

Because of trial-to-trial variation, early results should not be relied upon to make variety decisions. A single trial may be an ‘outlier’ in the full data set, meaning it does not necessarily represent ‘typical’ performance. As more results are published, certainty usually increases.

However, even results from a single year need to be treated cautiously. This is why the RL yield means are based on five-year and four-year data for cereals and oilseed rape, respectively.

*Note: for minor crops (described) – spring oilseed rape, spring linseed, winter triticale and winter rye – results are published after all relevant trial data is available (because of the relatively low number of trials).

AHDB commercial harvest progress reports will also commence later this summer. The reports are based on data provided by a network of regional reporters (mostly independent agronomists). Reporting frequency varies, with more frequent updates issued during the main harvest period.