Recommended List 2020

Provisionally Recommended varieties (PR) are tested for a minimum of three years before being added to the list in PR1. They are tested for a minimum of three further years before potential promotion to the fully Recommended (R) group. All varieties are issued with an automatic 1-year warning of removal from the list if their adjusted root yield values are below 100% of the controls. Varieties may be recommended for Specific Use (S) if they have specific attributes but are inferior to recommended varieties in other important characters (generally yield) and they justify limited use.  

Candidate varieties are usually tested using 1 kg samples of seed supplied by breeders. Once a variety has been provisionally recommended for commercial use, its seed is drawn from the commercial bulks as supplied to Germains. The bold figures in the supplementary table indicate varieties that have been tested with commercial seed; usually 500 units or more. PR1 varieties have been tested using only breeders’ seed provided as 1 kg samples. PR2 have been tested with commercial seed in the most recent test year but with breeder’s seed in the previous two. Similarly, PR3 have been tested with commercial seed in the most recent two seasons whilst only data for R varieties have come from trials using commercial seed in all three years. Where seed lots smaller than 500 units are supplied, these are classified as breeders’ seed. The data where all three years and the mean are in bold are most representative of the commercial situation.

The 2020 RL yield data are presented as a three-year mean of 25 trials (10 in 2016, 7 in 2017 and 8 in 2018). ( ) around data on the 2019 and 2020 tables (or [ ] around earlier data) indicates it is not a full data set with at least one year missing.  “-“ indicates no data.  The data for the 2019 and 2020 individual years are available in the supplementary tables.

If selecting a range of varieties it may be beneficial to make selections of material from different genetic backgrounds and the listing of Breeders and their UK agents is intended as an aid for this selection.

Provenance Tables (PDF Download)

In previous years disease ratings for rust and powdery mildew were taken from separate trials that were not treated with fungicide.  In 2018 one rust trial was continued; this type of trial is not taken to yield but two additional trials were set up that are designed to be taken to yield and to record all diseases. In the 2020 RL table, only rust data is available; there being only one year’s data for powdery mildew and other diseases.  The current rust data does not indicate tolerance or resistance, but simply leaf infection. The data in the RL table are ratings whilst those in the supplementary table are recorded percentage leaf infection.

2020 Rust data (See RL and Supplementary tables - PDF Download)

2019 Rust and powdery mildew data (See RL and Supplementary tables - PDF Download)

2018 Rust and powdery mildew data (See RL and supplementary tables - PDF Download)

Growers can use the establishment figures when calculating the seed rate required to produce their target plant population. In practice, the differences recorded between current varieties in trials are relatively small and those less than 4% are not statistically significant in the 2019 RL. In addition, growers need to consider that 'establishment' will vary between years (e.g., 90% in 2015 RL trials, 87% in 2016 and 84% in 2017). Growers can verify germination of their commercial seed lots (see Germains’ germination tables below), which will allow them to make final adjustments to the seed rates of the lots they are drilling.  

Establishment figures in the tables are presented as % of controls. Since the 2013 trial season seed has been sown at 6-9 cm seed spacing and thinned to produce an average population, for yield determination, of just over 100,000 plants per hectare. Pre-thinning plant counts are used to determine the establishment figures. Whilst this is not a true record of establishment (as number of seeds sown is not counted and the plant counts are carried out at the 2-4 leaf stage) it does indicate the small differences that can exist between recommended varieties and seed lots.

The germination figures are those supplied to the industry by Germains and are not part of the official RL testing.

Provenance Table for 2020 seed (PDF Download)

Germains Germination Table (800 bulk) for 2019 sowing (PDF Download)

Germains 2018 New Varieties Germination Results for 2019 sowing (PDF Download)

Provenance Table for 2019 seed (PDF Download)

Germains Germination Table (700 bulk) for 2018 sowing (PDF Download)

Germains 2017 Bulk Carryover Germination Results for 2018 sowing (PDF Download)

Germains New Varieties (new to 2019 RL) Germination Table (PDF Download) 

2017 Establishment Table (PDF Download)

2017 Seed Provenance Table (PDF Download)

Sugar beet is a biennial plant that will only become reproductive (i.e. produce a flower, or as it is usually referred to in beet “a bolter”) once it has been exposed to low, vernalising temperatures (for bolting) and long days (for seed production).  Temperatures between 3 and 12°C are the critical temperatures for vernalisation, with temperatures in the mid range having greatest effect and those towards 12°C the least. As a rule-of-thumb around 40 days of vernalisation (where temperatures during the 24 hours are within this range) are required for beet to bolt. Vernalisation can start before the beet emerge, therefore depth of drilling can have an effect on bolting.  Other factors such as field location (north or south region of the beet growing area, by the sea or inland, sheltered by woods or buildings, sloping topography and orientation of field) can also affect the temperatures experienced by beet, and hence vernalisation.  In some instances high temperatures immediately after a cool vernalising day can neutralise this (devernalisation).

Early sown bolting (ESB) trials are sown separately to the main RL trials and are now drilled sequentially from the last week of February to the 5th March. The ESB figures are the number of bolters recorded from these earlier sowings for the last three years and should be used as a guide to compare varieties by growers sowing early and / or where high vernalisation (periods of cold) is expected.

ESB figures can be generally classified as the genetic's tendency to bolt under bolting pressure. Later, Normal Sown Bolting (NSB) is often classified as production bolters or contaminants where another source of pollen has pollinated the female plant.  Plant breeders take care to minimise this in their seed production by ensuring good isolation distances and closely aligned flowering and pollination timing but, inevitably, there may be some year-to-year differences in bolting within a variety.

ESB and NSB figures are quoted as number per hectare based on beet populations of 100,000/ha.  

The table below provides the vernalisation experienced at each of the ESB bolting trials included in the 2019 RL dataset.

2020 Vernalisation in early sown bolting trials (PDF Download)

2019 Vernalisation in early sown bolting trials (PDF Download)

2018 Vernalisation in early sown bolting trials (PDF Download)

2017 Early Sown Bolting (PDF Download)

2017 Normal sown bolting (PDF Download)

2017 Vernalisation in early sown bolting trials  (PDF Download)

Since 2007, some AYPR rhizomania strains have been identified at a few sites which continue to be monitored and breeders have developed varieties with enhanced resistance genes to the AYPR strains found at these sites. Yields of the AYPR varieties are determined in the normal RL trials, which are carried out in non-infested situations.  Glasshouse studies, using soil collected from AYPR-infected sites, are used to determine their effectiveness at reducing the build-up of this.  Roots of these varieties are tested for the presence of the virus using established diagnostic methods. AYPR approved varieties should be used where this strain is present – but consult BBRO/your BS Area Manager/seed breeder for advice on managing this strain of rhizomania.

Beet cyst nematode (BCN) tolerant varieties are listed for use under BCN infested conditions but have yields suitable for use in non-infested fields. However, before selecting a BCN tolerant variety for non-affected situations it is suggested growers discuss this with BBRO and/or their British Sugar Area Manager. BCN tolerance does not apply to free-living nematodes such as those causing Docking Disorder. The BCN tolerance breeding technology has been demonstrated, in independent testing in the UK and mainland Europe, to give yield benefits under BCN infested conditions. The RL List is not indicative of the performance of BCN varieties under nematode infestation but yields are those determined in the normal RL trials, which are carried out in non-infested situations. With tighter rotations, BCN could be an increasing problem in some beet crops but generally this problem remains patchy within fields. It should be remembered that oilseed rape and many other brassica crops act as good hosts for BCN too, and rotation remains a key control method.

Based upon breeders’ submissions the BCN varieties could be listed as resistant, tolerant or light tolerant to BCN infection. Only tolerant types are currently listed and marketed. These types are able to produce higher yields than conventional varieties under these conditions and cause lower multiplication of the nematode population compared to conventional varieties.

The interaction of these varieties with the pest, and multiplication of BCN are complex issues influenced by a number of interrelated factors including starting population, cyst viability, sugar content, drilling date, soil type and weather. Breeders have their own information on the use of BCN varieties, as does BBRO. If you require further guidance or advice discuss with the specific breeder, BBRO or British Sugar Area Manager.

The 2020 RL includes the first ALS herbicide tolerant variety for the UK.  The herbicides for use with this variety were approved by HSE in March 2019 and are expected to be available for the 2020 growing season. In the RL trials the variety was treated with conventional herbicides. More details of use of the variety, including performance when treated with ALS herbicides, are expected to be available from the companies involved later in 2019.