Hybrid wheat varieties show real promise
Hybrid wheat varieties show real promise
sfdjasslfj
By Andrew Blake
HYBRID wheat varieties, with their extra vigour, are well placed to overcome the yield constraints of less than ideal growing conditions. But growers switching from conventionally bred types may need to change their approach to growing the crop.
Careful attention to drilling depth and a readiness to delay nitrogen applications should be well rewarded.
Those are strong messages from France where 150,000ha of DuPont hybrids – representing 6% of seed sales – were grown last year. Some are in first year commercial UK production (Arable May 18).
The firm, which took over Hybrinovas breeding business in 1998, markets 12 hybrid wheats, half of which are potentially suitable for the UK. None of the six ideally need sowing before October, suggests project leader Robert Bird.
All have been created using the chemical hybridising agent Croisor (sintofem) which leaves no residue problems, he says.
Quite apart from unnecessary expense, drilling hybrids too thickly undermines their vigour advantages, says technical manager Olivier Borde. But thin sowing makes it more important that each seed tillers well.
In 60% of the cases where French hybrid growers have been disappointed, sowing too deeply, which reduces tillering, has been to blame. "Deep drilling is often a problem, especially where soils are puffy."
Feedback from French distributors and researchers shows hybrids require their main nitrogen fertiliser later than conventional varieties. "With hybrids you waste N if you put it on early because they can use soil reserves better."
Trials at three UK sites confirm this. "On average we got an extra 0.5t/ha from applying most of the N later and no yield penalty from using no early N," says Mr Bird. On average delaying the N, but using the same overall amount, boosted margins by £32/ha.
Last year, in 50 UK grower trials of 2ha blocks, Hyno hybrids, mainly Hyno-Esta, gave on average 0.7t/ha more than conventional varieties like Consort, Claire, Equinox, Malacca and Savannah.
Half the crops at least covered their extra £40/ha seed cost. "One-third were significantly more profitable and all the farmers growing them have bought seed for this years commercial crops – from 2ha to 20ha each." About 450 such crops from Devon to Scotland are expected to provide valuable management information.
Last seasons results were based on a grain price of £65/t with conventional seed at £40/ha, and all crops were treated the same.
A firming wheat price, costlier conventional seed and more appropriate hybrid treatment should all work in favour of the new types, says Mr Bird.
Where UK growers were disappointed, excessive seed rate was a key cause. "On five farms they hadnt bothered to change the drill calibration and sowed 350-400 seeds/sq m in November." The maximum needed then is 180, he suggests.
"Their crops looked very good, but they got very high ear counts and lost all the hybrid advantage."
Portfolio of solutions
Rather than offering hybrid wheat as a single all-conquering concept, DuPont is concentrating on developing a range of varieties for specific end markets to add value for growers, says Mr Bird.
The ability to introduce new varieties within five years to suit niche outlets is seen as a particular advantage of the hybridising system which uses parent varieties of known quality.
"The traditional breeding industry is looking at a minimum of 2.5% of the seed market and needs to gain 5% to make any money. We can work with small volumes and quickly create a wide range of varieties suitable for end-users needs."
Hybridising agent assurance
Flour millers hesitation over accepting grain produced using chemical hybridisation has recently been overcome, says Mr Bird.
"Millers are pretty comfortable. We have addressed it and given them the information on Croisor. Its a non-issue." No sintofem, which could be approved for UK use by 2004, has been detected in grain grown from hybrid seed produced using it. *
HYNOWHEATHUSBANDRY
• Later drilling advantage.
• Sowing depth critical.
• High seed rates unnecessary.
• Benefits in delayed N.
Heterosis help
Hybrid vigour reduces the yield limiting effects of later drilling, second wheats, poor establishment, variable soils and climatic stress at sowing and during grain fill.
Mr Bird says these are the main reasons why UK average wheat yield is 8.5t/ha and not the 13t+/ha it could in theory be.