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Arable

Three-year data gives better understanding of bolting With the cold and dry weather dominating the early part of this season’s sugar beet growing campaign, bolting scores should be high on growers’ agenda when selecting varieties from the newlylaunched Recommended List. Dominic Kilburn writes. Those that took that chance of drilling early this season will probably get a 15–20 per cent yield advantage with their crops over those planted later, says plant breeder SESVanderHave.

It is vital that growers study variety bolting scores across ‘three-year data’ on the new sugar beet Recommended List before making their choice of seed for next season’s crop. And, with several varieties on the latest List designated as ‘unsuitable for sowing before mid-March’, options for choosing varieties suited to early drilling are narrowing. That’s according to breeder SESVanderHave UK general manager, Ian Munnery, who said that if ever there was a season in which to have the flexibility of getting the crop in the ground at the right time, it was this one. Speaking in mid-May, when much of the current crop across the sugar

beet growing region was struggling to establish following the persistent cold and dry conditions experienced this spring, he said that it had been key to get some crops in early. “Temperatures remained low for much of the spring, and soils dried out, and I believe this will cause significant levels of bolting in June and July. “But for those growers who got their seed in early, into moisture, crops will have got up and away quickly and avoided some of the problems seen in other crops in terms of the weather, and of course pests. “Its not rocket science. Growers must drill when the conditions are right to get the best establishment, and those that took that chance of drilling early this season will probably get a 15–20 per cent yield advantage with their crops over those planted later,” he suggested. However, having the flexibility to drill early carries the risk of early

bolting which will reduce yields and increase costs, he warned, and pointed out that as many as nine varieties on the new List are unsuitable for drilling before mid-March because of their susceptibility to bolting. “Looking at the three-year bolting data is critical,” he stressed. “If you take our new variety Bloodhound, for example, it has a mean of 2,882 bolters/ha – the lowest on the List – and that includes 2015 and 2016 which were both cold years that resulted in high numbers of bolters across trials. “Some of the other varieties performed OK in 2014 – a mild and low bolting year which you get every so often – but then they bolted like crazy in 2015 and 2016. And if you consider that on next year’s List the three-year mean figures will lose data from 2014, the bolting scores on some of these varieties will be very much worse,” he explained. “Every 1 per cent of bolting is at least 1 per cent loss of yield and so growers don’t want to be losing 20 per cent yield because of bolting. “Yes, you can use the higher bolting varieties for later sowing but then you have to take the chance with the weather and eventual yield loss,” he added. Mr Munnery also cautioned about headline-grabbing yields on the RL. “There’s a raft of varieties which

promise exceptionally high yields. Try some by all means but note that some are only provisionally recommended from a 1kg trials seed sample. More relevant is to look at data from larger (>500kg) commercial bulks. This is now highlighted in bold on the official BBRO/BSPB Recommended List and is integral to achieving ‘fully recommended’ status only after three years testing with larger commercial bulks. “Each year, SESVanderHave UK conducts some 20,000 trials across the key sugar beet growing areas of Britain. Our UK focused programme has delivered varieties with real staying power such as Cayman and Springbok which have been fully recommended for several years,” he concluded. ■

said BBRO. Do check product labels for recommendations for minimum crop and maximum weed growth stages (paying attention to rates of usage) to avoid checks in growth and damage, particularly where crops are stressed, advised the organisation. Some general guidelines are available in the BBRO Sugar Beet Reference Book

which can also be found on the BBRO website but always check the product labels to confirm rates or contact your agronomist, it added. Tailoring choice of herbicide to control the key weed species present is key and being prepared to change rates and even products between fields may give the best control. ■

SESVanderHave UK general manager, Ian Munnery with new variety Bloodhound.

Beet crops see steady growth at last After weeks of slow growth, rainfall and warmth saw crops begin to accelerate with the more advanced crops fully established beyond the 6-leaf stage, reported the BBRO in its mid-May Advisory Bulletin. However, for many crops progress remained slow with patchy emergence and canopies somewhere between emergence and

the 2–4 leaf stage. Some crops showed variability both within and between fields especially where there were differences in rainfall, soil type and field topography. The resulting range of different growth stages is a challenge when making decisions regarding herbicides, weed control and fertilisers,

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