Described as a breakthrough by industry commentators, Troy is one of six new varieties to join
the 2013/14 HGCA Recommended List for the East/West region and one of nine added to the North
Standing out from the crowd is difficult in such circumstances. But the fact that it’s the
first semi-dwarf variety to perform as well as standard height oilseed rapes has been noticed, and
that’s before its management and harvest benefits have been considered as well.
DSV’s trials manager, John Sweatman, has grown Troy for the last three years and is quick to
point out that it has a very different growth habit and physical appearance to other
“Most relevant to this year is the fact that Troy doesn’t exhibit any of the early
sluggishness that has been reported with previous semi dwarves,” he says. “It seems to have the
autumn vigour that we’ve seen with the best standard size hybrids.”
Getting a plant population of 35-40 plants/m² in the spring is the target, he explains, which
is why this is so important. “It also helps it cope with less than optimum soil conditions, late
drilling and bad weather – things which were all an issue last autumn.”
Two distinct phases of vigour have been observed in the field, he reports. “The first is in
the autumn period, which gets the crop established and allows it to grow away from pest and pigeon
damage, while the second is in the spring.”
The spring ‘kick’ sees the plants growing quickly to 1.3-1.4m, advises Mr Sweatman. “It is
taller than other semi-dwarves,” he acknowledges. “But the extra height does seem to give it higher
With the physical bulk or biomass, but not excessive height, Troy never gets tall enough to be
unmanageable or prone to lodging, he adds. “Its compact growth habit is also a bonus when applying
nitrogen or sprays, as well as making it quick and easy to harvest.”
Case Study - Lodging
Lodging was a serious problem for Derbyshire grower Rob Holmes last year, despite reducing the
amount of nitrogen he applied to his oilseed rape crop in an effort to keep it
Familiar with oilseed rape varieties getting ahead of themselves on his good land – which
tends to carry a lot of residual nitrogen - Mr Holmes has seen varieties getting too tall before.
But 2012 was a real eye opener, with big name varieties suffering badly.
For this reason, he drilled 35acres of Troy last Autumn. “I’d looked at semi-dwarves before as
a way round the problem, but wasn’t too impressed with their yield potential,” he
As his focus is on output, Troy was considered and chosen for part of the farm’s oilseed rape
area. “It appealed because it should stay standing, regardless of soil nitrogen. But in addition,
its yield and gross output potential is right up there with the best. “
Despite the bad conditions last year, Troy established well at an even plant population of
30-35 plants/m², he reports.
“In a good year, it should produce returns as good as anything else, but in less than perfect
conditions it should still deliver even when the others are falling over.”
Case Study - Harvesting
Standing power has become a priority for Lincolnshire grower Sam Markillie, but harvesting
benefits are also high on his list of variety characteristics.
“Last year we had some issues with lodging so standing power has become more of a priority
when choosing which variety to grow. But we’ve also found that combining OSR is becoming more
problematic,” he says.
That’s because crops are often very tall, with green stems that the combines find difficult to
handle, he explains. “Harvest pressure results in us raising the combine header to increase output
and reduce losses so we are left with waist high stubble which is less than ideal for the following
His decision to drill 80 acres of Troy was taken before the variety had been recommended, but
he was impressed by the combination of its compact growth habit and yield potential.
“A semi-dwarf should minimise harvest problems by its very nature, but the yield penalty has
been too great to contemplate them until Troy came along.”
Establishment was even with good vigour, he reports.
Case Study – Pest Problems
Swans are the main pest problem for Cambridgeshire oilseed rape grower Paul Hartley, who
admits to having had crops decimated in previous years.
“They’re attracted to large plants with a lot of top,” he says. “So a smaller plant should
suffer less, but until now the performance of existing semi-dwarves just hasn’t been there."
As a result, he has 50 acres of Troy in the ground. “We couldn’t get hold of it last year,
which was a shame. It’s the first semi-dwarf to have the yield performance.”
He direct drills his oilseed rape crops into stubble, to try and deter both swans and pigeons.
“Troy’s got lots of ‘get up and go’ which means it should be hardy enough to grow through early
attacks by swans and pigeons.
“Further on we are hoping its compact growing habit will give it protection against the swans
and allow it to remain standing, so we should get an easier and quicker harvest than last year.”&
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