28 May 1999

Early drilling sends up wheat yield – and still more to come

By Andrew Swallow

SWITCHING to early drilling allowed Cambs grower John Steel to push wheat yields to nearly 11t/ha (4t/acre) last harvest.

Now even higher yields are hoped for from the heavy clay soil at Manor Farm, Hamerton. "This year we are aiming to average 12t/ha," he says.

Drilling starts on Sept 10, with just 120 seeds/sq m aiming for 100 plants/sq m. But only if conditions are right. "You must have a good seedbed and moisture if you are drilling that early. Nothing messes up germination more than drilling into a warm dry seed-bed," he stresses.

The seed rate is increased 2-3 kg/ha every couple of days, to reach 200 seeds/sq m by Sept 20. A power-harrow/drill combination system capable of 40ha (100 acres) a day means drilling his 125ha (310 acres) of wheat should be complete by then.

"And as we are using a combination unit we dont leave a fine seed-bed undrilled that could slump if we got heavy rain," he adds. A roll and cross-roll after drilling ensure soil is consolidated to prevent any seed loss to slugs.

Drilling depth is set to ensure there is moisture for the seed and emergence is expected five days from drilling. No field-loss is allowed for. "All of our seed is seed-table separated so we only have grains with plenty of energy, plenty of starch, in them. Last autumn we ended up with 115 plants from 120 seeds," he says.

Equinox and Consort are the main varieties this season. All wheat is first wheat, following peas or oilseed rape. "That means we can have all the land ploughed and ready before we start combining wheats," he says.

The open canopy does lead to slightly more weeds, but no extra cost as controls would be necessary anyway, says Mr Steel. "Also there is less disease in the crop as it doesnt form a favourable micro-climate. That increases the potential to yield a tremendous amount."

The first fungicide is applied early, at GS30, with a Moddus (trinexapac-ethyl) plus chlormequat plant growth regulator aimed at increasing rooting. Full rate Mantra (kresoxim-methyl + epoxiconazole + fenpropimorph) was used this year, aiming to protect the crop from early March through to flag leaf. "It should last 80-100 days with a full unit," he estimates.

A second Moddus/chlormequat application is followed by Terpal (ethephon) at GS37 if needed. That is mixed in with the flag leaf emergence spray of strobilurin/triazole, which went on in mid-May this year. A two-thirds rate of strobilurin is used, followed by a further third as an earwash before flowering.

Nitrogen is delayed until after the first fungicide to avoid crops becoming too thick, too early. And the total is limited to just 120kg/ha (96 units/acre) applied in two doses. "In thick crops so many tillers abort. But in crops like ours nearly every tiller produces a big ear. They are like a sausages on sticks," he says.

Total variable costs are under £250/ha (£100/acre), with savings on seed have been absorbed by extra expenditure on strobilurins.

But Mr Steel is convinced the investment in new chemistry is worthwhile. "The gross margins speak for themselves."

BOX

CAMBS EARLY DRILLER

* 12t/ha target from 120kg/ha N

* Sept 10 start, moisture essential

* Two units of strob in three sprays

* Clean from GS30 – avoids disease ladder effect

Set in a panel

RHYNCHO WARNING

SPRING barley growers are warned to keep a close eye on rhynchosporium following severe levels in the winter crop, says BASF.

"It has been the dominant disease in winter barley, and the spring crop tends to be even more susceptible," says business development manager Johnathon Peck. Both Landmark (epoxiconazole + kresoxim-methyl) or Mantra (epoxiconazole + kresoxim-methyl + fenpropimorph) have very good activity against the disease, he adds.