Syngenta is urging growers to be timely with fertiliser applications to hybrid barley this season, as part of a checklist to help maintain the crop’s high yield potential after the difficult winter. Charlotte Cunningham reports.

Early spring nitrogen is always important to ‘feed’ the crop’s vigorous growth, says Syngenta seeds technical manager, Paul Roche. But with this season’s potential for backward crops with reduced tiller numbers after the wet winter, ensuring that sufficient nitrogen is available early, so that active growth is not held back, will be particularly important, he notes.

“Clearly, fertilisers need to be applied within industry regulations and according to FACTS qualified advice and local conditions,” says Paul. “However, a typical programme would be to start by applying 30% of the total nitrogen dose for the season as soon as conditions are suitable in early spring during tillering, at about GS25. This would be followed by 50% of the total dose at, or just before GS31, and the final 20% some 2-3 weeks after that, typically by the end of April.

“If these splits aren’t possible, then applying 50% of the total dose at the first timing and 50% at the second timing is an alternative. But avoid late nitrogen applications because there will be a risk of stimulating secondary tillers.”

In blackgrass situations, Paul says Syngenta trials have shown early nitrogen applications are essential for maximising the crop’s blackgrass suppression – with both these programmes, of either 30:50:20 or 50:50:0, having performed well.

“Fertiliser applications should be avoided when soils are snow-covered, frozen hard, waterlogged or deeply cracked,” he adds. “Care is also required on sloping ground adjacent to watercourses.”

Other factors in Syngenta’s hybrid barley checklist this year include being aware that leaf emergence and node growth stages may not match, says Syngenta hybrid barley manager, Mark Bullen, and correcting any rooting or stem strength deficiencies following the wet winter.

Risk factor

“Winter barley crops, in general, that were drilled late or that have sat in waterlogged soils over winter will be at risk of poor root growth,” explains Mark. “Also, a peculiarity of late-planted winter barley is increased risk of stem weakness. This happens because late crops try to catch up by growing rapidly, producing thinner stems that are more prone to lodging or brackling below the ear.

“Both rooting and stem strength can be targeted with the correct plant growth regulator (PGR) programme. Our guidance is to consider a low dose of Moddus + chlormequat at GS30, primarily to promote rooting; followed by a repeat at GS31-32 to shorten and strengthen stems; and a later PGR to reduce final straw height.

“With risks of fast growth in late crops, it will also be important to check fields regularly to stay on top of spray timings. Plants should be dissected to identify the correct leaves have emerged when timing fungicides. With hybrid barley’s large flag leaves, a well-timed T2 fungicide is important. As well as controlling disease, the fungicide Elatus Era at T2 has also been seen to reduce brackling in barley. This could be particularly useful where there are risks of weak stems in fast-growing, late-drilled crops this year.”

Among the various disease risks to watch out for in barley this season, Mark says mildew can take a bigger toll in small, backward barley crops, and Ramularia is especially important to prevent rather than attempting to cure.