31 May 1996

PUTTING BEET IN TO SHARPER FOCUS…

Focus on Beet marks the sugar beet crops introduction to the Cereals Event. Robert Harris highlights some of the topics that will be on show, identifying some issues which could affect growers this season

PLENTY of beet experts will be on hand at Cereals 96 to demonstrate how growers money is being spent on research and to discuss the practical implications.

Demonstration plots show the latest ideas resulting from Sugar Beet Research and Education Fund work on early season agronomy. Seed dressings, drilling dates, crop nutrition and weed control systems are examined in detail to ensure crops make a good start.

Representatives from British Sugar, IACR-Brooms Barn, Morley Research Centre and the National Institute of Agricultural Botany will be available to answer growers questions and to suggest ways of putting the results into practice to help improve production.

Mike May, from Morley Research Station in Norfolk, believes the event, co-organised by Morley and British Sugar, will prove popular.

"The site is on a lighter type of soil, and is fairly shallow. But it is typical of a lot of beet land. And the messages will be relevant to all growers, whatever soil type they farm. The location is ideal – there are a lot of cereal growers within striking distance who also grow sugar beet."

DRILLING DATE

Quick establishment and good bolting resistance are the hallmarks of modern sugar beet varieties. They can be drilled earlier than older types which helps to boost yields.

"Growers now have the potential to start drilling around Mar 10, rather than the traditional start date of Mar 20. Pulling the national drilling window forward by 10 days should increase average yields by 3t/ha."

While there have always been those who drill early on lighter soils, Mr May believes all growers should consider it. But, like this year, soil and weather conditions may overide this.

Visitors will be able to compare beet drilled at three different dates. First plots were drilled on Mar 18 to reflect commercial practice – some 5% of the Bardney factory area (the nearest one to the site) had been drilled by then.

Planting resumed on Mar 23, by which time 25% of commercial drilling had taken place. Final plots were sown about three weeks later.

Matching variety to drilling date helps, although it is less crucial than it once was given the general overall improvement in varieties. "Go for a high-emergence, low-bolting variety first. You can tolerate those more susceptible to bolting later on," says Mr May.

A new seed treatment ideally suited to early drilling is being demonstrated at the event. Advantage, developed at Brooms Barn and commercially available available for the first time this year, is a warm steep treatment that promotes seed development.

"In most seasons an Advantage-treated crop will reach 50% emergence three to four days earlier than an untreated one," says Mr May. "That is especially useful where you need to get the crop through quickly, for example on soils prone to capping, or where pests are likely to be a problem."

It also promotes more even establishment, easing subsequent management, he says. A useful spin-off is that crops from treated seed appear less susceptible to bolting, another good reason for using it early. "At about £13/unit, it could be good insurance."

SEED TREATMENTS

Chemical seed treatment has largely replaced granules as the growers main weapon against sugar beet pests.

Several treatments will be examined. "Granules still have their place in treating problems like Docking disorder," says Mr May. "But where this is not a problem growers now have the opportunity to use seed treatments like Force (tefluthrin), which is very effective against other soil pests, and Gaucho, which also controls aphids."

Gaucho (imidacloprid) is a valuable tool where virus yellows is a problem, he explains. "Dr Alan Dewar at Brooms Barn has shown it is effective for up to 14 weeks. That has taken the headache away from aphid control."

The only disadvantage is that growers have to order treated seed before they know how serious the aphid problem will be during the coming season. Some 50% of growers ordered Gaucho-treated seed last autumn. But after the hard winter the virus yellows forecast is low. "British Sugar is looking into the problem to see if they can give growers more flexibility," says Mr May.

NITROGEN MANAGEMENT

Visitors will be able to pick up some useful tips on matching both inorganic and organic nitrogen to crop need.

Too many growers still apply the wrong amount of bagged nitrogen at the wrong time, says Mr May. "There is an optimum. Beyond that, yields dont increase, but impurities rise while sugar content and extractable sugar levels fall."

Nitrogen application should be split, with a starter amount being spread on the seed-bed and the rest when the crop has two leaves.

"Traditionally some growers go at four to six leaves. Thats too late. Nitrogen must be there when the crop needs it, from two leaves onwards, when the main sugar-producing leaves are developing in the primordia."

Poultry manure also comes under scrutiny. About 20% of growers use it to bulk up light soils, but in much greater amounts than is needed, boosting impurities while depressing yield.

"The optimum is about 6t/ha," says Mr May. "But it is extremely difficult to apply that amount accurately. When you realise that many growers are putting on 50t/ha and often nitrogen as well, you get an idea of the problem."

WEED CONTROL

A range of weed control systems to suit different farm businesses will be on show, paying particular attention to cost and management input.

"The main purpose is to get growers to think about weed control strategies. They need to look at their management first – how much time, labour and machinery they can dedicate to weed control. Then they can choose a system to suit."

The standard pre-emergence application followed by two post-emergence sprays has been used on some plots. A typical programme might include chloridazon (eg Pyramin) followed by metamitron (Goltix) and oil, then a phenmedipham (Betanal) and lenacil (Venzar) mix. "The cost is reasonable, but it needs careful timing and the treatments have to be right for the weeds."

Morleys FAR system has been used on others. This usually consists of four post-emergence sprays, and is about 15% cheaper than the standard treatment, he reckons.

Applications are made weekly, so the farm needs to have sufficient machinery and labour to cope. But the number of applications allows some product flexibility, since there is more opportunity to control survivors in a later pass.

British Sugars two-spray programme is also under test. This involves two post-emergence applications; the first going on at the two-leaf stage, the next a fortnight later. Higher rates of active chemicals and oil are needed, but it is easier to manage.

So too is Morleys high-dose system. This programme uses a high pre-emergence rate of chloridazon + ethofumesate (Spectron or Magnum), typically followed by desmedipham + ethofumesate + phenmedipham (Betanal Progress) plus a residual at two leaves. "It needs little management and is very flexible on timing. But it is costly… about 50% above the traditional approach."

Debut (triflusulfuron methyl), a new sulfonylurea herbicide, is also being tried with a range of other products in a three-spray programme. The site has a good range of weeds present, which Mr May expects will provide a good test.n

A seed treatment that promotes faster emergence could be especially useful on soils that are prone to capping or where pests proliferate.

Early season agronomy comes under the spotlight to help boost yields come harvest. Co-organiser Mike May expects the event to be popular.