7 October 2000

Patience pays

Late autumn-sown wheats did surprisingly well after beet last year. Gilly Johnson asks how best to ensure a repeat performance.

GIVEN a little tender loving care, late-drilled wheat doesnt have to be a poor relation in the rotation – particularly behind sugar beet.

This is one case where the tortoise may have the edge on the hare, says Ben Freer of the Morley Research Centre. "Dont be impatient. First, its not when wheat is drilled that makes the difference – its the state of the seedbed the crop goes into. And second, you may do better from letting the beet bulk up longer."

Proof of the pudding comes from November drillings last year; excellent yields from Morley trials reflect ideal late-drilling conditions during mid-month, following sugar beet. Its true that there is some yield penalty to pay, but it may not be as great as you think, says Mr Freer. At Morley, wheat drilled promptly (11 Oct) on a light land, post-beet slot averaged higher yields – 10.36t/ha (4.2t/acre). But the more traditional 12 Nov drilling date on heavier land managed an exceptional 9.96t/ha (4t/ha).

Working through the figures, that extra 0.4t/ha yield from earlier drilling is unlikely to be enough to outweigh the sugar yield foregone by lifting the beet earlier. The argument is strengthened by the fact that late-sown wheat can also be cheaper to grow – perhaps by £20-30/ha (£8-12/acre), and by choosing a milling variety; theres also the prospect of a quality premium.

Of course, late autumn sowing doesnt always do as well as last year. Five-year averages from NIAB would suggest that a more realistic penalty might be 1.5-2t/ha (12-16cwt/acre). But even at this level, it could still pay to leave the preceding beet crop in the ground for longer.

A beet crop will bulk up by an extra 12t/ha between September and November. At A/B prices of £30/t, thats worth £360/ha. And if youre worried about missing quota target, then this sugar is even more valuable. But even at C beet prices (£9/t or so) theres £108/ha to gain – the equivalent of almost 2t of feed wheat.

The calculation is complicated by early delivery bonuses for beet, but this year these will only be paid for the first few days after factory opening, because opening dates have been put back following the fuel crisis. So far less cash will be paid out for early delivery; bonuses are ignored for the purposes of this article.

Morley has developed a gross margin analysis programme that will calculate whether it is worth lifting later, and drilling later, in individual farm circumstances; this software is downloadable by e-mail. Anyone interested should ring Martin Lainsbury (01953 713200) at Morley for more details.

Varieties do perform differently in a mid-November drilling slot. Some growers have traditionally used quality spring wheats to fill the gap, but now there is a growing range of wheats with the flexibility to suit pre- or post-Christmas drilling; they may be classed as spring or winter varieties. If drilling is delayed, then spring types offer a safety net in that they can be sown very late.

NIABs autumn-sown trials (below) show that the barn-filling feeds are a tough act to beat – even at the later drillings. But potential challengers would be Charger, a fast-developing Group 2 wheat which has found favour late autumn-sown; Malacca which had an excellent year; and Claire, the new biscuit wheat.

"Do the sums on premium potential," says Mr Freer. "If you can find a premium which will offset a 7-10% yield penalty, then a quality wheat is worthwhile."

He recommends a cheap, general purpose seed treatment, unless wheat bulb fly is anticipated; thin beet crops and bare soils increase the risk. "If you know youve a problem, consider using Evict. Watch seed rate. Try and achieve at least 300 plants/sq m; which at a 1,000-grain weight of 52g, would mean a seed rate of about 200kg/ha."

Savings on autumn insecticides, spring fungicides and growth regulators could add up to £30/ha, he suggests. "Its unlikely that youll be able to miss out a fungicide spray, but you could get away with a lower dose rate, and no late season growth regulators."

Fertiliser applications should be prompt in the spring. "Dont starve the plants; you dont want to lose any tillers."

The critical decision is whether the soil condition is right for late drilling.

"If the ground is rutted, with standing water, then dont attempt taking the drill through. If conditions are right, then many people will lift the beet, and then take a plough and combination drill across. Sometimes the beet harvester can do the tillage needed itself, and you can follow with the drill. And if the soil is fit, then it does make sense to drill as soon as possible, because the longer the wheats in the ground, the higher the yield potential."