A Guide to the New Recommended List Hosting Scores

Changes to the AHDB recommended list help growers better manage the risk of lodging of different cereal variety options for planting this fall.

It was suspected that over the years, hosting ratings were becoming more similar, says Ellie Marshall, AHDB’s chief field trial analyst.

“We weren’t seeing a lot of diversity in the ratings,” she says.

See also: How to Prevent Lodging in Spring Barley

Lodging ratings for all varieties contracted from year to year, showing little discrimination between each variety.

“But there was no evidence that was actually happening on the ground,” she says.

Another illustration of the shortcoming was that even without accommodation, it was not possible to obtain a score of 9 (the highest on the scale of 1 to 9), she says.

New calculation

The AHDB therefore undertook to modify the calculations to extract more varietal differences and add diversity in the notes.

A key change was the addition of resistant and sensitive fixed points on the regression slope, similar to disease ratings.

This means no lodging will generate a score of 9 and the lower end of the scale will consistently represent higher incidences of varietal lodging.

This allowed the rating to extend to both ends of the scale, showing more discrimination between varieties.

The change has been implemented for all cereal varieties on the current recommended lists (2022-23).

This has led to changes in the ratings of some varieties. “This is due to resetting the scale rather than a change in accommodation sensitivity,” Marshall points out.

For example, Fusion oats, which have good standability, previously scored 8 (recommended lists 2021-22) for lodging and now have a score of 9 on the 2022-23 lists.

Examples of Hosting Score Changes

Note in the recommended list 2021-22

Note in recommended list 2022-23

Winter wheat – Skyscrapers

seven

6

Winter barley – Thunderbolt

6

5

Winter Oats – Fusion

8

9

For wheat and barley, lodging is also expressed as a percentage for each variety.

For example, growers looking for a soft Group 4 will see a lodging score between 1% (swallow) and 13% (skyscraper), when using a plant growth regulator.

Don’t forget the LSD

When comparing the varieties on the list, she says that the least significant statistical difference (LSD) should be taken into account.

Variety score differences that are larger than LSD are likely to reflect a true difference, as they would occur by chance less than 5% of the time.

However, differences smaller than LSD are more than likely to occur by chance and should be treated with caution, she says.

For example, for winter wheat, the average LSD for lodging without plant growth regulator is 1.1, so the difference between Gravity (6) and Graham (7) should be treated with caution, while the he difference between Gravity and Costello (8) represents a real difference.

Accommodation costs

Lodging is expected to affect up to 20% of UK winter wheat acreage every few years (three to four).

Early lodging results in the greatest economic losses, due to its greater impact on the grain filling period. Lodging around ear emergence can cause yield losses of up to 75%.

Lodging also negatively affects quality characteristics, such as Hagberg falling number and test weight. Affected crops often require additional drying.

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