The BBROs winter conference got underway at the East of England Showground in early February
The BBROs winter conference got underway at the East of England Showground in early February. Dominic Kilburn attended. A recent BBRO survey has identified that about six per cent of the land used for growing sugar beet in the UK is affected by beet cyst nematode (BCN). What is more, BCN numbers can increase by as much as 3040 per cent in one season, highlighted BBRO lead scientist Dr Mark Stevens (left) at this years BBRO winter conference. Mark suggested that BCN box and field trials had identified that introducing a non-host crop into the rotation, such as spring barley, can result in a 90 per cent decline in BCN over three years. Trials growing Bullfinch in BCN populated soil saw a rapid build-up of numbers which peaked in the spring of the second year, but declined when spring barley was introduced, he said. Current recommended varieties including Sentinel, Mongoose, Pamina, Thor and Pitbull had been developed for tolerance and were providing yield performance in BCN-infested land while reducing build up in the future. In field trials in Norfolk from 20102013, six out of eight trials gave a positive performance in terms of yield as well as a decline in BCN populations, he added. Mark pointed out that in addition to being a problem for sugar beet, BCN also liked oilseed rape and therefore growers should think about the impact of other crops in the rotation. Trials workHe said that new BBRO trials work was comparing four different mustard and radish catch crops in the Fens to understand their impact on subsequently grown beet crops. The good news from 2013, said Mark, was that the AYPR strain of rhizomania, although still present, had not given rise to any new cases, however rigorous monitoring by the BBRO was continuing. 2013 was the first year that all varieties sown were rhizomania partially-resistant and variety strip trial work has demonstrated the benefits of varieties with two resistance genes against the AYPR strain. There is excellent material in terms of current varieties available to contain it, suggested Mark. One of the root rots to be aware of was rhizoctonia not a new disease to the UK but one that was, to date, adequately controlled by the fungicides applied to the seed at processing each season. However, he pointed out that several countries on the Continent were having problems with the disease, which can appear in a number of different strains. Of concern is that some of the strains that are found in sugar beet are also found in maize and with increasing amounts of maize being grown in areas of the country where sugar beet is prominent, this could be a problem for the future, commented Mark. In the Netherlands, many growers have switched to growing rhizoctonia-resistant varieties as the disease has been such a problem and being a common pathogen in the UK with a wide host range, its a warning to growers over here. According to a recent British Sugar crop survey, only four per cent of beet growers in the UK elected not to use fungicides to protect their crops from foliar disease in 2013 and BBRO trials continue to demonstrate yield benefits between untreated and treated crops. 2013 was a low disease pressure season, particularly in terms of early mildew because of the extremely cold spring, but, none-the-less, yield comparisons of two- and three-spray programmes all continued to show considerable yield benefit over untreated plots, Mark pointed out, with the two-spray programme demonstrating the best yield response in 2013. The advice is to apply the first fungicide of the season at full rate for optimum disease control and use a two-spray programme for October-onwards lifted beet, he added. New diseaseMark said that a new disease to watch out for is stemphylium a threat that has been in the Netherlands since 2007. With a fungus which can cause symptoms similar to rust following rain (yellow spotting), it can have a yield impact as much as 40 per cent if left unchecked. As well as in the Netherlands, stemphylium is also found in German and Belgian beet crops and of slight concern is that some of the key sugar beet fungicides currently being applied to the crop dont have an effect on it. That said, some potato fungicides do control the disease and so while theres no need to panic, its one to watch for, he suggested. In terms of other foliar diseases; downy mildew was showing increasing signs of affecting earlier stages of the crops life than it used to and a new BBRO project will look at the potential of phosphites for its control. Traffic controlThe cost of soil degradation in England and Wales is now as much as 1 billion per year, of which compaction accounts for 39 per cent. That was one of the opening statements from CTF Europes Tim Chamen, an expert in controlled traffic farming. He pointed out to growers that, currently, up to 85 per cent of a typical arable field is trafficked during the course of a season and the aim of controlled traffic farming, or CTF, was to turn that figure on its head by keeping 85 per cent of land traffic-free. The main benefit of CTF was to improve crop yields, he continued, and although recent German research had found that sugar beet benefitted less from CTF compared with crops such as barley and oats, research had confirmed that for all crops there is some positive yield benefit, in addition to: less requirement for subsoiling; less fuel spent on tillage (as much as a 35 per cent reduction); the use of smaller tractors; better stale seedbeds; maximum potential for min-till; better infiltration of water into the soil; less water run-off and more plant available water. Traffic is also bad for earthworms, he added. Tim said that only an RTK GNSS system provided the repeatable track positions required for machinery to return to year after year. He conceded that CTF was more complicated to achieve in vegetable and root crop producing systems; especially when it came to harvest, but he suggested that a CTF system based on the 45 years prior to growing sugar beet would build up good soil structure and would help the soil to resist compaction when it came to harvesting the beet crop. Research reviewSummarising the findings of the recent BBRO review of research priorities in crop production, Nottingham Universitys Dr Debbie Sparkes said that with future research areas identified, there was still a big opportunity to increase commercial sugar beet yields in this country, particularly as, in 2013, on average, they lagged behind variety trial yields by 6t/ha. Focusing on crop nutrition, she commented that all the indications were that application rates of 100120kg N/ha (the current recommendation for nitrogen in sugar beet) were about right. Nitrogen application rates to sugar beet are linked to the optimum canopy size of the crop sugar beet needs nitrogen for the canopy to intercept light, she said. Sugar percentages start to decrease above the 120kg N/ha application rate on mineral soils, she added. Debbie concluded that on-going work (collaboration between the University of Nottingham and the BBRO) will address three main areas: understanding and overcoming limitations to water uptake by the crop; identifying rooting traits for optimal nutrient uptake and improving establishment and early growth. Scanner aids testingA portable 3D plant laser scanner has been developed by Strube as a part of an armoury of tools to measure key parameters in the growth of beet. The scanner allows the recording of emergence characteristics, plant numbers, plant quality and plant homogeneity to give an objective evaluation of the quality of crops in the field without interfering with the plants, says the company. The importance of these new techniques is underlined by Strube UK managing director, Richard Powell: To make sure that genetic improvements are realised in every growers field, we continue to invest in the techniques that make sure that we can produce high quality seed in volume.