This series is sponsored by KWS.
The arrival of KWS Trinity to the 2015 HGCA Recommended List has concentrated interest in the quality wheat sector with promises of high yields, good disease resistance and milling quality grain.
At 102% of controls, KWS Trinity makes the most of its Grafton and Einstein pedigree, with the joint highest UK yield of all Group 1s and top for eastern counties at 103%. It was the first to pass nabim’s new commercial-scale test for milling approval without concern and has the potential to become a leading breadmaker.
But Trinity’s extra yield potential over traditional milling wheats will require a fresh approach to nitrogen management to fulfil its potential and meet end user requirements, says Agrii agronomist David Irvine, who advised on the crop grown to milling specification last season.
He says: “The biggest issue with Trinity is growers have to raise expectations about what can be achieved and how much nitrogen is needed to fulfil yield and meet millers’ protein requirements.”
Any crop with predicted yields at or above 11 tonnes/hectare will, subject to N Max audit regulations, require somewhere close to 300kg/ha of available nitrogen if it is to achieve 13% protein, he says.
“This will be more than many growers normally use, but is around the level needed to counter protein dilution from high-yielding crops.”
KWS product development manager John Miles says most milling wheat growers are used to applying 250-260kg N/ha, but insists the extra investment is worthwhile.
Mr Miles says: “It is a similar situation to when Malacca and Xi19 were introduced. All of a sudden, there was a massive step-change in yield potential which required a fresh look at how to grow the crop.”
Trinity’s low protein on the Recommended List (11.4%) is not indicative of the potential, he adds, as RL trials are grown to a feed wheat protocol with no adjustment to nitrogen for milling types.
Timing nitrogen applications correctly is as important as total dose and reserving some for late in the season is a key way of boosting grain protein, says Mr Irvine.
For last season’s 20ha (50-acre) block of Trinity grown at Streetly Hall Estate in South Cambridgeshire, this meant a total of 310kg N/ha split four ways, with 50kg N/ha going on in early March, followed by two more granular applications of about 100kg N/ha each, before the final application of 40-60kg N/ha applied as an ear spray.
Mr Irvine says: “It is quite a dry part of the country, so we tend to put slightly more on in the first of the main applications and go with liquid nitrogen for the last dose to help uptake.”
Farm manager Paul Norman says the approach worked well with the crop achieving a final yield of 10.85t/ha, protein of 12.8%, a Hagberg falling number of 407 seconds and 83kg/hl specific weight.
He says: “You need to spend a bit more on fertiliser to get the protein, but at those yields it is worth doing. “We are growing 35ha of Trinity again this season and assuming it performs well, it has potential to become our main milling variety.”
Trinity’s strong disease profile, especially against rusts and mildew, makes it relatively easy to manage with a good fungicide programme, says Mr Irvine.
“So long as you get spray timings right, you should not have to fight against anything.”
He acknowledges the septoria rating of 5 is a slight weakness, but insists it does not alter the fundamental crop management.
Mr Irvine says: “This year, we are using an SDHI at T1 and T2, but this is no different to our approach for any other milling wheat.”
Philip Simons of Prime Agriculture also likes the variety, having advised on an area grown for seed on light land in Norfolk last year. “It looked a cracking variety which stayed clean right through the season, despite quite high disease pressure. We kept spray intervals close to three weeks and used SDHI-based fungicides at T1 and T2, plus a robust prothioconazole-based T3 to cover late septoria and fusarium.”
Mr Miles says Trinity is a medium tillerer which is best suited to drilling from mid-September onwards.
Although it has relatively short stiff straw (rated 8 for lodging with PGR), growers are advised to avoid over-thick crops which could reduce specific weight and protein. Aim for final ear numbers of 450-500/sq.m. Beware of orange wheat blossom midge too, as the variety is not resistant.
|Variety||Mildew||Yellow rust||Brown rust||Septoria tritici||Eyespot||Fusarium|
Source: HGCA 2015/16 Recommended List