…but could pgrs have helped more?

11 July 1997

…but could pgrs have helped more?

ADVICE not to use regulators because it was so dry earlier this year, is partly responsible for lodged crops now, says Hutchinsons Mr Neale.

Tests on the silty clay at Wisbech, one of four Hutchinson trial sites, highlight the value of sticking to proven programmes, especially split treatments.

Several different approaches are being compared on Rialto wheat and Halcyon barley. Untreated wheat is leaning quite badly. "Another good thunderstorm and it will go down," comments Mr Neale.

Full dose (2.5litres/ha) New 5C Cycocel (chlormequat + choline chloride) at first node (GS31) has thickened the crop and helped maintain tillers in the drought. But the stand still looks a little unsafe, he says.

Full dose (2.5litres/ha) Meteor (chlormequat + choline chloride + imazaquin) at the same timing produced a rather more open crop which seems equally unsafe. "As last year it has not taken so much height off as the 5C."

Full dose (0.4litres/ha) Moddus (trinexapac-ethyl) helped wheat through the drought leaving it greener without stressing it, he notes. "But I am still not overly happy with it. There are some long stems in it."

Half Moddus alone seems no more useful than full dose 5C Cycocel, he adds.

A single GS31 tank-mix of quarter dose Moddus with 1litre/ha of 5C costing about £8.50/ha (£3.50/acre) is a strategy more growers should adopt to strengthen crops, Mr Neale suggests. For producers aiming at very high yields double those rates can easily be justified.

Investing less than £3/acre can be worse than spending nothing, because of so-called bounce-back, which may severely weaken stems halfway up, he argues.

Extra costs

Growers seeking yet more assurance should be prepared to bear the extra application costs of using two treatments, each of 0.1litres/ha of Moddus + 1litre/ha of 5C Cycocel at the start of stem extension (GS30) and at GS31. "It wont fall over," he comments on a plot so treated. "We would follow up with Terpal in sticky situations."

Doubling the doses in the final split approach did not stress the crop. "But we spent more than we needed."

Using Moddus/Cycocel mixtures on barley is not advisable, Mr Neale warns. "The effects are too severe and unreliable. They certainly keep the crop standing but tend to reduce yield." But Moddus alone can be very useful.

Full label dose on the crop is 0.6litres/ha, but Hutchinson tests show good results are possible with half that. A plot so treated at GS31 has partially lodged but is already reviving, a result of the typically bowed basal stem strengthening the chemical provides, Mr Neale explains.

A single 0.4litres/ha dose offers little extra advantage, he notes. The firms preferred route is split treatments of 0.2litres/ha, at GS30 and 31, backed up with Terpal where necessary.n

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