Take your time with Beet crop establishment – Farmers Guide – Matt Ward
Good crop establishment is going to be a challenge on a lot of land this spring. Dominic Kilburn seeks some timely advice on establishment and weed control for sugar beet...
Sugar beet growers will understand more than most the challenges they currently face to get crops established following the extreme weather experienced by many since last autumn. And while some land, or parts of fields, will already have been identified as “beyond hope” in terms of sustaining a crop this spring, a calm and measured approach to beet crop establishment will be vital over the next few weeks, growers are advised.
It’s a year when every field will have to be taken on its own merits, believes Farmacy agronomist and services leader, Matt Ward.
“Individual fields within the boundaries of the same farm may have to be treated differently, says Mr Ward, who advises growers in West Norfolk and Lincolnshire. “My client base includes a variety of soil types from blowing sands to Lincolnshire boulder clay, and good silts-they are all in the same boat and they know only too well the challenges ahead.”
While there has been a move to drill earlier over the past few years backed up by data that, overall, suggests crops do yield better when drilled early, he says that there is no need to rush if drilling hasn’t started as yet. Two years ago we saw that the earliest drilled crops didn’t perform so well, and the April-drilled area did very well that year. Soils can really start to warm up in April and any spring crop will respond to that.
“Even if you have done nothing to the land as yet, and still have to plough, take your time as some soils could still be very wet and it could result in a plough pan,” he says.
“It’s an old cliché, but attention to detail is needed – get a spade, dig down and have a look,” he adds.
Equally, where cultivations have already taken place, Mr Ward says that cultivated tops will dry out and it will suddenly look like the field is ready to be drilled. But take a look underneath where the soil can still be a mess.
You don’t want freshly drilled seed to be sitting in cold, wet soils. So don’t move the soil until it is ready to be drilled,” he stresses.
“It’s inevitable that some land is beyond any productivity this spring, and as I said to cereal growers throughout the autumn – don’t just drill because you have a drill in the field.
“Sugar beet is the same – the middle of the field can be in relatively good condition and the headland terrible. Identify those areas. You are not going to meet your contract tonnage just by putting beet in the ground. And poor beet crops will affect the following crop.
“We know that beet is a high risk crop in terms of soil management and so it’s not a good idea to risk the headland getting trashed again and then having a negative knock-on effect for the rotation for a whole year. It’s much better to get it right now.”
Mr Ward suggests that if a headland does have to remain undrilled, then growers should consider drilling it with a cover crop when conditions allow. And one idea he is looking at closely is the prospect of adding in a brassica crop to the mix.
“My thinking is that if a brassica is added to the cover crop mixture, alongside the main beet field, then it could potentially act as an early warning for myzus persicae – peach potato aphid – the main vector for virus yellows in sugar beet, of which numbers are expected to be high again this year.
“You are more likely to find the aphid in a brassica such as rape ahead of the beet and so my theory is that, as an agronomist going into beet crops looking for aphids, I could simply go to the field edge and gauge the level of threat by what I see in the cover crop. If l can’t find any there then I probably won’t find any in the beet crop, he says.
“I will encourage some growers in that situation to give it a try,” he adds.
Mr Ward says that he will advise growers to get early nitrogen on the seedbed, and while a lot of land won’t even have had base fertiliser applied as yet, he cautions as to the quantity that is applied if it’s close to drilling.
“A lot of potash, for example, is put on with the beet crop for the whole rotation but to avoid elemental toxicity, it may be prudent just to apply a sufficient amount for that crop only, and then come back at a later stage to top up the rotational requirement,” he concludes.
With two key sugar beet herbicide actives in their last season of use, be sure they are applied on farm by their specified use by dates, advises UPL national influencer Pam Chambers. Products containing either chloridazon or desmedipham can no longer be sold onto farm and final use dates are 30th June and 1st July 2020 respectively, she points out.
“Where possible this season, if conditions allow, aim to apply glyphosate pre-drilling/before crop emergence to remove any weeds already present,” she advises.
“The use of a pre-em herbicide should be considered where black-grass is expected and also where the optimum timing of the first post-emergence spray may be difficult to achieve.
“In addition, where crops are drilled and soil temperatures remain cool, with little growth, this is another good opportunity for a pre-em,” she comments.
“If drilling late, evaluate the need for a pre-em spray, especially on sites where black-grass is not an
issue and travelling on the land is not generally a problem,” she adds.
Cloridazon is one of four actives (excluding graminicides) with approval for use pre-emergence in beet crops although there will be limited availability, while metamitron (such as in Bettix Flo and Goltix 70 SC) and ethofumesate (as in Efeckt) are likely to be the most frequently used especially where black-grass is the main target, she says. Other pre-em product quinmerac is only available in
partnership with metamitron.
“Where black-grass is expected, use at least 500g/ha ethofumesate but remember to reserve some for post-emergence use while keeping in mind the 1,000g/ha maximum total dose over a three-year period on the same field.
“Include metamitron for resistance management and to boost annual broad-leaved weed control,” she says.
Life after Des
There will be some programmes this season where desmedipham will not feature, and growers can’t assume that phenmedipham is a straight gramme for gramme replacement for it, she continues.
In UPL 2019 trials, 300g of phenmedipham + 60g desmedipham was comparable with 600g of phenmedipham across the T1, T2 and T3 post-em spray timings with respect to total weed control.
“It may change depending on the weeds targeted but more phenmedipham (as in Betasana SC) will be required,” she adds.
“In adverse conditions, where weeds are tough and hardened, the use of adjuvant oils or higher rates of actives with contact activity, such as phenmedipham and ethofumesate, will be required.
“Spray intervals may need to be tighter if weeds start to grow away in warmer April soils, and so it’s important that growers understand the strength and weaknesses of individual actives and relate this to the weeds that are present when deciding on product choice and rates” she explains. More information on weed control can be found on the BBRO website: www.bbro.co.uk.
“In 2018, drilling was generally a month later than normal and, in many cases, post-em sprays were applied at temperatures over 20oC (see chart), and weeds and beet were actively growing.
“In 2019 a more normal season prevailed with temperatures at spray application much lower, sometimes into single figures with frosts at night, and this resulted in the slow growth of weeds and beet”, Ms Chambers says.
“Every season can be different and temperatures can vary dramatically, having a huge impact on the sensitivity of weeds and the beet crop itself to herbicides, so adjust rates of actives used according
to the conditions”, she concludes.
The Herbicide Resistance Action Committee (HRAC) mode of action classification system has recently changed from a lettered listing to numeric. Growers and advisers need to familiarise themselves with the new system to ensure that different modes of action are incorporated into herbicide programmes for resistance management.
ADAS senior research consultant Dr Sarah Cook believes the change has been made to bring global classifications together under one system. For further information she advises growers and agronomists to visit the HRAC website and click on “Tools” where the mode of action classification 2020 map can be found and downloaded.
Waterlogged and compacted soils could cause emergence issues for stressed sugar beet crops this spring, according to Omex crop nutrition agronomist Scott Baker. To help mitigate some of these issues Mr Baker is advising growers to consider applying biostimulants such as phosphite-based Kickstart to encourage seedling rooting and to boost canopy development.
Trials at the University of Nottingham Sutton Bonington showed that applying Kickstart increased root mass by 35 percent when applied at the 2-leaf stage, with similar results when applied at 6-leaves.
“In glasshouse work an early application of Kickstart increased shoot weight by 9.6 per cent,” he says. “And in a field trial that suffered waterlogged and patchy establishment, when applied at the 6-leaf stage, the product still gave a 9.5 percent increase in green area in September and a healthier canopy, supported by a better root system. The plots showed an 8.4 percent yield increase and a 2 percent sugar increase, which boosted the adjusted yield by more than 11 per cent.”
Mr Baker also points to work with Bio 20 – a biostimulant plus Complete nutrient foliar product – which has shown a positive yield enhancement in a wide range of crops, particularly when applied in stress conditions.