The British Beet Research Organisation has undertaken a detailed and independent investigation of the 2013 sugar beet emergence issues including commissioning work from UK Universities and government agencies as well as European Institutes and laboratories.

Issues with "Erratic emergence" in sugar beet crops in England caused widespread concern amongst growers earlier this year. Problems were first noted in late April and were reported across beet varieties, with emergence and vigour both being affected.

The studies were based and designed around samples and comments received by the BBRO from growers, agronomists and British Sugar area managers. The organisation said it has not analysed all varieties and their respective treatments, but instead deliberately concentrated on those seed lots where issues were identified via the British Sugar complaints process.

All 2013 commercial seed supplied to growers, as agreed by the NFU and British Sugar, was processed as Xbeet^® plus. There were no equivalent batches of Xbeet^® treated seed for direct comparison in the research organisation's studies. BBSRC said, "Scientifically, this is disappointing, but we have tested and have had access to everything that was commercially available. Previous seed stocks from 2012 are available but these cannot be compared directly to seed sown by growers in 2013, as they would have represented different bulks of seed with only the Xbeet^® treatment."

However, Germains did process several small non-commercial batches of raw seed, originally supplied by the breeding companies, with either Xbeet^® or Xbeet^® plus and the BBRO continues to test these.

Consequently, the BBRO has investigated three sources of seed representing Cayman (bulks 252, 258 and 259), Pasteur (282) and SY Muse (211,212,223,224,225,227 & 228) and their respective seed treatments of either Poncho Beta, Cruiser Force or Nuprid 60, as well as standard seed and the original raw seed lots supplied by the breeders to Germains. These seed lots came from:

• Germains retained samples
• Commercial boxed samples from the Frontier seed store
• Grower specific samples

From on-going BBRO studies, the following has been identified:

Germination tests using filter papers

• At above 16^oC, all seed, regardless of variety or treatment, germinated at or above accepted Industry standards in traditional germination tests. Very few abnormal seedlings were observed, again in line with Industry tolerance levels.
• Decreasing the temperature of the test increased the germination time as expected, but all Xbeet^® plus treated seed lots achieved over 94% germination within 27 days at a mean temperature of 8.5^oC.
• At 8.5^oC differences in the rate and final germination of the raw seed of the three varieties and their bulks were observed (the germination of the different varieties ranged from 42 to 90% after 42 days). These differences were not observed once primed and pelleted by Germains.
• Decreasing temperature increased the number of abnormal seed types, including the twisted hypocotyl and black root tip phenomenon. The percentage of abnormal seedlings varied between varieties, their bulks and final processed seed. In one particular grower sample, the number of abnormal seedlings counted was double (40%) that of an equivalent retained sample (21%) from Germains.
• Although variations were seen in the speed of germination, there were no differences in the final percentage germination of the non-commercial batches of Cayman, Pasteur or SY Muse when treated with either Xbeet^® or Xbeet^® plus (range 95-100%).
• Further cold tests remain on-going.

Germination tank tests

In addition to the previous germination studies, further tests were commissioned that allow seeds to germinate on filter paper suspended in water tanks so that roots can grow unimpeded to a depth of 30cm. These tests continue but to date have shown:

• More abnormal seedlings (twisting/ curling/ black root tips) were observed than the standard tests described above, and were evident at 18^oC.
• Differences between varieties and bulks identified in the above tests were reconfirmed by these studies.
• Tests remain on-going at lower temperatures.

European soil emergence test

BBRO commissioned a European laboratory to evaluate all the above seed lots using an Industry accepted test that is performed on a compost/sand mix at a constant 10^oC for 17 days. These tests showed:

The final stand of all seed lots was good (over 99%) by the end of the test. However,

• All raw seed batches had a delayed emergence compared to Xbeet^® plus seed lots.
• Differences in the speed of emergence were observed between varieties and their treatments.

Pesticide loading

The loading of the neonicotinoid seed treatments on seed was tested at two different laboratories. Both confirmed that thiamethoxam (Cruiser), clothiadinin (Poncho) or imidacloprid (Nuprid) were present on appropriate seed lots. On some occasions the loading was just outside the standard limit but the organisation said, "we do not feel this to be significant."

Weather analysis

The BBRO is working with Weatherquest to analyse all complaints data against a range of weather and soil variables to understand the impact of the cold, dry seedbed conditions in 2013. During the sowing period from which most complaints originated (i.e. 20th March to 8th April) the air temperature was, on average, 6^oC colder than the long term average. BBRO said, "We are aware though of emergence issues with several re-drilled crops in late April and early May following wind blow."

Global perspective

Most of north-west Europe experienced a cold, dry spring following a very wet autumn and winter period. Consequently, seed beds were often challenging to produce, although the very dry period during March and early April helped to produce a fine tilth for sowing spring crops. A number of final plant stands have been affected according to reports received. In addition, following recent IIRB meetings in France and North Dakota, USA (a similar spring was also experienced there) poor shaped roots are being reported in these countries that look similar to those found on some UK farms. The UK research organisation is currently assessing domestic fields that experienced emergence issues earlier in the season for root shape.

The variety Pasteur also suffered from emergence issues in countries such as France, and these have been attributed to interactions between the pellet type and weather, leading to a hardening of the coating and consequent problems with germination. A novel test has just been developed by scientists in Europe to identify the cause of this problem and the BBRO is currently investigating this further via its European contacts to evaluate UK seed batches

BBRO's Conclusions & Recommendations

• There were no differences in the final percentage germination of the non-commercial 2013 batches of Cayman, Pasteur or SY Muse seed when primed and pelleted as either Xbeet^® or Xbeet^® plus (range 95-100%).
• Standard germination tests conducted above 16^oC showed acceptable levels of germination (95% plus) of all commercially processed seed.
• The BBRO has highlighted differences in the germination and number of abnormal seedlings within tank and cold (stress) tests between bulks of the same variety as well as between retained and grower samples of the same finished product. This is being investigated further.
• BBRO believe that all seed should undergo cold temprature as well as standard tests to identify any potential issues under cold stress. However, if adopted, this would have implications for commercial seed processing and its on farm delivery.
• The BBRO suggest that further samples are kept throughout the seed processing procedure so that lots can be re-evaluated when issues arise such as experienced in 2013.
• The BBRO believe future studies are required to investigate the relationship between overall seed size, its embryo and the impact on germination under stress conditions.
• No emergence issues were recorded in any of the BBRO/BSPB variety trials and these were treated with the Germains plus pellet only; we are currently devising a root shape evaluation protocol for these trials once processed at the BBRO tarehouse.
• BBRO will investigate the use of extended weather forecasts as a risk management tool at drilling.
• We encourage all growers to record the location of each variety within fields to assist with any future investigations regardless of issue.

Overall, BBRO estimates that the 2013 emergence issues have been caused by a number of interacting factors, but the prevailing weather during the sowing period has played a significant role in triggering the problems seen earlier this year, as these were also encountered elsewhere in northern Europe. Further germination tests are on-going to reconfirm these findings and the BBRO will be recommending a series of pellet trials in 2014.