24 March 2000

Cereals come to fore as potatoes dropped

Combinable crops and non-

farming matters are getting

more attention than usual on

farmers weeklys midlands

barometer farm.

Andrew Blake reports

WITH no potato planting to worry about for the first time in 10 years, Robert Tallis is busy fine-tuning his cereal input strategy. The benefit of a modified autumn herbicide policy is already showing, and nitrogen applications are being adjusted.

Hitting T1 spray timing accurately should also be easier. With winter crops at Frolesworth Farms, near Lutterworth, Leics about three weeks ahead of normal, that is expected to be in early to mid April. "In the past I have often had to get on before the end of March because we wanted to get on with working potato ground."

First change was to omit diflufenican from autumn herbicide mixes. "We often have to clean up broad-leaved weeds in the spring," explains agronomist Malcolm Harrison. "Even with high rates of IPU and DFF we invariably had to go back for cleavers. So we thought lets deal with grass weeds and get some of the chickweed and polygonums and then tackle the rest in spring."

The new cheaper approach, based on only 2litres/ha each of IPU and trifluralin, with Lexus (flupyrsulfuron) substituted for IPU on known blackgrass fields, worked well. "The overall saving was £8-9/ha, and we have gained a cash flow advantage. Some chemicals now fall into the buying groups summer payment period instead of the winter."

"We do have rather more broad-leaved weeds especially in our early sowings," says Mr Tallis. "But we would have had to spray for them anyway."

Despite drilling dates from Sept 15 to Nov 20 (after potatoes) all wheats last week were between GS25 (mid-tillering) and GS30/31 (the start of stem elongation). "We might have expected them to be from 24 to 32, but the spread is much narrower than it first appears," says Mr Harrison. "Thats mainly because its day length that drives development."

However, with most crops at GS30 Mr Tallis has been keen to apply some nitrogen, especially to second wheats. "HGCA research shows early N helps counter take-all," he says.

"I am happy with that, because it wont be pushing vegetative growth at this stage," says Mr Harrison. Soil sampling in first wheat after oats, highlighting only 6.9kg/ha (5.5 units/acre) of available nitrogen in the top 60cm (2ft), explains yellowing starting to show before top-dressing.

For the first time liquid ammonium sulphate has been used instead of straight liquid N. "Its a sensible move to include sulphur on this light land when we are aiming for 10t/ha," says Mr Harrison.

"The only draw-back is that it is a bit more time-consuming because I have to use 600 litres/ha to get the 50 units/acre on," says Mr Tallis.

"Until now Ive only had to use 200."

In the past first top-dressing was often up to 88kg/ha (70 units/acre) to ensure crops did not run short during potato fieldwork.

To try to boost grain protein, 38kg/ha (30 units/acre) of the balance may be held back until early May, the only concern being scorch. "That can usually be overcome by working in the evening."

Plenty of breaks mean eyespot is rarely a problem and this year is no exception. So Unix (cyprodinil) for second wheats in Mr Harrisons strategic plan has already been dropped from the TI spray.

Main target – septoria

Main target is septoria. "There is quite a lot about so we shall need an eradicant with a small amount, 0.25litres/ha, of Amistar to retain the green leaf." The curative element will be Opus (epoxiconazole) at 0.75 litres/ha for early sowings and second wheats, and 0.5 litres/ha for thinner, later drillings. Strobilurin Landmark (epoxiconazole + kresoxim-methyl) was used last year. "But of the available strobs we find Amistar is better against septoria."

Mildew in Claire will merit adding 75ml/ha of Fortress (quinoxyfen). "We have had some very good results with Fortress on mildew in oats," says Mr Tallis.

For the T2 spray doses will be reversed so there is more strobilurin to protect cured leaves. "We may try the new trifloxystrobin, F279. But the most important thing to reduce the risk of resistance is never to use a strobilurin alone," says Mr Harrison.

Without potatoes competing for attention on the farm, cereal growth stage triggers should be met more easily this season, say Robert Tallis (right) and independent agronomist Malcolm Harrison.

SPRING STRATEGIES

&#8226 No potato planting.

&#8226 More time for cereals.

&#8226 Modified herbs & N.