22 November 1996

Fast start OK for some

Some growers hit by earlier drought may be regretting drilling early. But one group of enthusiasts has come through relatively unscathed. Robert Harris discovers why

DESPITE fields being left high and dry for several weeks after drilling, most of a band of Lincs-based early-drilling enthusiasts have established good crops this autumn.

They are well-placed to repeat this years yields which often exceeded 11t/ha (4.4t/acre), says John Bayes, a director of Lincoln-based supplier Agrochem South. "About 15-20% of our customers have moved to earlier drilling. But the failure rate this year is not high – only about 5% of the group have had to re-drill."

The reason, he believes, is exceptional management skill. "People have to be fully committed. There are no half measures. If management is off the pace, things can soon go wrong."

Establishing and maintaining the correct plant population is the secret to success, he stresses. That starts with cultivations – care is needed if crops are to germinate and emerge quickly and evenly, especially in a dry time as this year.

Moisture conservation is vital. "People have got better machines, better presses and a clear understanding of how to use them. They do not plough large areas and leave them to dry, but disc and press within half a day. We want consolidation and moisture conservation, but not compaction."

Soils must not be overworked, he adds. "In dry conditions, soils are loose. Too much cultivation loses tilth down the profile."

Using healthy seed and being able to drill it at the right time is a major concern, says Mr Bayes. "Most of our members are seed growers and use their own."

No time to buy seed

With a typical start date of Aug 24, there is no time to buy seed, he adds. "Merchants cant deliver early enough." Some members grow several varieties in one field so they can harvest them in one day, dress them the next and drill the day after, he explains.

Favoured varieties are Riband, Buster, Slejpner and Consort – straw strength, resistance to stem-based disease and slow growth habit are important features.

Seed needs to be healthy to get the best start, says Mr Bayes. Many growers apply manganese to the seed crop at flag leaf (GS39) to ensure seed is not deficient. Seed is usually gravity separated to select the boldest, most vigorous grain.

Sowing the right rate is crucial, to avoid over-thick crops. Early sown crops tiller vigorously, so lower seed rates are needed. For August and early September sowings 80-100kg/ha is typical; 150kg/ha for late September ones.

"Our lowest seed rates give plant populations of 120-150/sq m, though each plant produces five to six tillers, so the ear number is high. But such low populations provide no buffer if anything goes wrong – you only have one chance to get it right."

Seed spacing needs to be accurate – bunching must be avoided to allow seeds to tiller freely. That often means drilling slowly – soils tend to be fluffier and drier than later in the season, exacerbating the problem, explains Mr Bayes.

If redrilling is needed, either whole fields or large enough square or rectangular patches should be sown. This avoids mixed growth stages which can compromise spray timings, says Mr Bayes.

Drought is the main reason for crop failure this early, and redrilling into still-dry soils is cheap compared to later failure, he says. Land does not have to be pulled up, and relatively low seed rates can still be used, keeping costs down.

Once crops have emerged, careful management is needed to preserve the better growth and to maintain the right tiller population. Patience is needed with herbicides. "Before applying residuals, you have to wait for rain to close the seed-bed." Otherwise seed can be harmed, and clods may break open later allowing weeds to grow through. Early, soft crop growth is also more vulnerable to herbicide damage.

Early flushes of soft weeds like oilseed rape volunteers and chickweed should be removed with one or two low doses of a sulfonylurea herbicide. Multiple insecticide applications may also be needed to protect the crop against BYDV – aphids are more likely to infest early-emerging crops. "Most of our members use low water volumes, and big 24m sprayers. They are prepared to spray two to three times in the autumn."

Micronutrients are often added – tissue testing is routine, although Mr Bayes recommends higher than normal rates to allow for his members higher yields.

Early-drilled crops are more advanced in the spring than their later-drilled counterparts. "We still apply the main nitrogen dose just before stem extension but this tends to be earlier," he says.

Feeding the crop is important to maintain early growth and tiller numbers, he adds. "There is more moisture at this time, so the plant makes better use of the nitrogen. Even if the weather turns dry later on the crop will never look back."

Meteor growth regulator (chlor-mequat + imazaquin) is sometimes used in the autumn, especially on lighter soils, to encourage better rooting, further protecting crops against late spring drought.

It is used universally in the spring. Early applications are not needed since multi-tillered crops show little apical dominance, but later timings are used to preserve straw strength. "Meteor is taken up faster and gives a more dramatic response than straight chlormequat, particularly under cool conditions," says Mr Bayes. &#42

Early sown crops tiller vigorously, so lower seed rates are needed to maintain the correct ear number, says Lincs agronomist John Bayes. Early spring growth regulators are not required, but later treatments are essential.


QUICK START PLUSES


&#8226 Higher yields possible.

&#8226 Low seed rates save costs.

&#8226 Healthier, stronger plants less prone to disease, lodging and drought in spring/summer.


EARLY DRILLING NEEDS


&#8226 Best suited south of Humber.

&#8226 High management standard needed.

&#8226 Early break crops – winter rape, winter linseed or peas- ensure enough ground cleared early.

&#8226 Home-saved seed for quick start.

&#8226 Care with cultivations and drilling vital.